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Guidance for hydrogen and fuel cell stationary applications

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1. 2 Installation Location Indoor Outdoor Remote Industrial Residential Yes lean to shed Additional information e g single multi family home rooftop laboratory etc Single family home Located in a shed attached to the house What affected your choice of site location Availability of site Installed by Name contact details Installation company Energised Ltd Manufacturer BAXI INNOTECH Gmbh Service company maintenance Energised Other 45 Please provide copies of installation manuals service amp operational manuals and training material 2 1 Before amp during installation Schematic drawing of installation electrical amp mechanical optional ee l l l l l F Site evaluation 1 What safety and security measures were taken for each component of the fuel cell system e g ventilation fire protection sensors barriers walls locks Considered under HAZOP and under site choice Fuel supply Piped YES Generated on site Stored on site 1 Describe the fuel storage and any safety devices related to the storage e g number of cylinders used size of tank used storage pressure materials used etc Natural Gas 2 Describe fuel piping used between components material length internal and external diameter if known shape connections etc
2. 46 N A 3 Describe what precautions were taken if the piping went through a wall type of wall type of sealing piping instructions fire protection smoke protection etc N A If the fuel cell was connected to a grid or appliance what criteria had to be fulfilled The fuel cell was connected to the grid Standard connection criteria for connection of distributed power generation to local distribution network was used G83 1 1 2008 Engineering Recommendations 2 2 After installation What training did the installers users and service personnel receive BAXI trained the installer and service personnel No intervention by the user What emergency procedures are were in place Fire Brigade were made aware of location of installation and a special tel number was issued in case of emergencies Remotely monitored by PLC by BAXI If an approval route was necessary describe by whom and what was needed The system was CE marked and similar procedures were followed as 1 installation Was any commissioning of the installation carried out If so please provide details Commissioned in lab and then re commissioned on site by manufacturer Please describe the service procedure Re commissioned on every service period of service based on usage running time and stops and starts 47 3 Lessons learned What were the challenges
3. CGA P 6 Standard Density Data Atmospheric Gases and Hydrogen Compressed Gas Association NFPA 50A Standard for gaseous hydrogen system at consumer sites National Fire Protection Association The Fire Protection Research Foundation Technical Report Siting Requirements for Hydrogen Supplies Serving Fuel cells in Non combustible Enclosures Safety distances IGC Doc 15 06 E Gaseous Hydrogen Stations European Industrial Gases Association IGC Doc 75 01 rev Determination of Safety Distances European Industrial Gases Association ISO TR 15916 2004 Basic Considerations for the Safety of Hydrogen Systems NFPA 50A 50B 52 and 55 National Fire Protection Association Fuel cells general BS EN62282 3 1 2007 Fuel cell technologies Part 3 1 Stationary fuel cell power systems Safety 41 Fuel cells general BS EN 62282 3 2 2006 Fuel cell technologies Part 3 2 Stationary fuel cell power plants Performance test methods BS EN 62282 3 3 2008 Fuel cell technologies Part 3 3 Stationary fuel cell power systems Installation Hydrogen fuel ISO 14687 1999 Hydrogen fuel Product specification ISO TS 14687 2 2008 Hydrogen fuel Product specification Part 2 Proton exchange membrane PEM fuel cell applications for road vehicles Hydrogen sensors BS EN 61779 Parts 1 to 5 Electrical apparatus for the detection and measureme
4. Health and Safety Executive Installation permitting guidance for hydrogen and fuel cell stationary applications UK version Prepared by Health and Safety Laboratory for the Health and Safety Executive 2009 RRS Health and Safety Executive Installation permitting guidance for hydrogen and fuel cell stationary applications UK version D K Pritchard M Royle amp D Willoughby Health and Safety Laboratory Harpur Hill Buxton Derbyshire SK17 9JN The HYPER project a specific targeted research project STREP funded by the European Commission under the Sixth Framework Programme developed an Installation Permitting Guide IPG for hydrogen and fuel cell stationary applications The IPG was developed in response to the growing need for guidance to foster the use and facilitate installation of these systems in Europe This document presents a modified version of the IPG specifically intended for the UK market For example reference is made to UK national regulations standards and practices when appropriate as opposed to European ones The IPG applies to stationary systems fuelled by hydrogen incorporating fuel cell devices with net electrical output of up to 10 kWel and with total power outputs of the order of 50 kW combined heat electrical suitable for small back up power supplies residential heating combined heat power CHP and small storage systems Many of the guidelines appropriate for these small systems will als
5. Introduction and Scope Chapter 1 Introduction to fuel cell systems and their associated hazards Chapter 2 General and Higher Level Requirements Chapter 3 e System Specific and Siting Considerations Chapter 4 Permitting Route Chapter 5 e Appendices Although it is envisaged that the information may be of interest to all user groups an effort has been made to organise information for ease of use by each user group particularly in Chapter 3 Chapter 4 contains additional information relating to specific systems as well as details on siting considerations The information in this document provides guidance on some safety aspects of the equipment This is not a substitute for meeting applicable standards codes and regulations Relevant standards codes and regulations are referenced where available in the text and Appendix 1 gives a listing of current codes and standards As many standards and codes are currently in development or only recently adopted and system designs have yet to be finalised by many manufacturers it may be some time before we can reasonably expect equipment certification to these codes and standards Certification including CE marking is not required for demonstration prototypes It is hoped that the guidance provided in this document can facilitate demonstration and early market installations A list of abbreviations used in this document is available in Appendix 6 References are pr
6. While Chapter 3 dealt with the general safety considerations this chapter deals with system specific and siting considerations mainly focused on fire and explosion hazards When seeking to control the risks associated with using hydrogen it is important firstly to take all reasonable steps to prevent a loss of containment of hydrogen secondly to ensure if there is a leak that a flammable atmosphere cannot accumulate thirdly to control potential ignition sources where flammable atmospheres may accumulate and finally to use suitable protection against the fire and explosion hazards The experimental and modelling programmes in the HYPER project considered scenarios related to the system siting and the reader is referred to the IPG and the HYPER website for further information on the results of these work programmes It should be noted that many of the regulations and standards cited in this chapter would not be applicable or relevant to residential applications For example the DSEAR and EPS Regulations only apply to the workplace Nonetheless it is recommended that the general principles in DSEAR be adopted for identifying hazards and implementing prevention and protection measures for residential applications 4 1 HYDROGEN GENERATION 4 1 1 Generation options Hydrogen can be produced at large central production facilities and delivered to the point of use or produced at the point of use an option that is not available for conve
7. phones and work clothing Precautions should also be taken to prevent the build up of static charges that may lead to an incendive discharge These may include e Ensuring that all pipe work is conductive and has effective electrical continuity especially over mechanical joints such as flanges e Ensuring that all pipe work and equipment is effectively earthed e Carrying out and documenting appropriate earthing continuity checks e Wearing antistatic clothing and footwear in hazardous areas Further information on the avoidance of hazards due to electrostatics can be found in the code of practice PD CLC TR 50404 2003 Appropriate protection is also required against the risk of lightning strike when designing outdoor fuel cell or hydrogen storage facilities 4 4 3 Explosion mitigation If explosive atmospheres may be present and ignition sources cannot be eliminated then measures to mitigate the effects of the explosion should an ignition occur and prevent the explosion propagating to surrounding areas are required There are a number of techniques available that can be employed to reduce the explosion pressure generated and or contain the explosion within a given area 4 4 3 1 Explosion venting In this technique weak areas explosion vents that fail early on in the explosion are deliberately incorporated in the item of equipment venting the combustion products and so reducing the explosion pressure generated inside the equipm
8. pressure and weather for outdoor locations related need to be taken into account Hazards that are likely to arise during the lifetime of the installation also need to be considered This would include those hazards associated with installation of the equipment start up and shutdown of the equipment delivery of consumables eg gas cylinders and maintenance and repair For domestic installations a fairly basic risk assessment will be sufficient and in some cases one may not be required at all e g for an integrated CHP system In these cases it is proposed that all that is required is that the equipment is installed according to the manufacturer s instructions as in drawing up these instructions the manufacturer will have undertaken a risk assessment Step 2 Check the equipment used in the installation complies with the essential health and safety requirements of all applicable EU Directives For fuel cells and associated equipment the applicable Directives will include the ATEX Directives Pressure Equipment Directive Machinery Directive Gas Appliances Directive Low Voltage Directive and Electromagnetic Compatibility Directive Step 3 Check the installation meets national legislation dealing with planning approval building regulations and fire regulations Installations that can export surplus electricity generated back to the distribution grid will also need to meet any regulations for interconnectivity of supplies Step 4 The equip
9. 3 2007 Fuel cell technologies Part 3 3 Stationary fuel cell power systems Installation HSG 243 Fuel Cells Understand the hazards control the risks 2004 HSE Books ISBN 0 7176 2766 7 HSE L56 Safety in the installation and use of gas systems and appliances Gas Safety Installation and use Regulations 1998 Approved Code of Practice and Guidance HSE Books ISBN 0717616355 Bulk LPG Storage at Fixed Installations Code of Practice 1 Parts 1 to4 UKLPG R J Lewis Sax s Dangerous Properties of Industrial Materials 1 j edition Volumes 1 3 John Wiley amp Sons November 2004 ISBN 978 0 471 47662 7 CP4 Industrial gas cylinder manifolds and distribution pipework pipelines excluding acetylene British Compressed Gases Association Code of Practice Council Directive 89 392 EEC of 14 June 1989 on the approximation of the laws of the member States relating to machinery Luxembourg 1989 OJ L183 29 06 1989 Council Directive 2006 95 EC of the European Parliament and of the Council of 12 December 2006 on the harmonisation of the laws of Member States relating to electrical equipment designed for use within certain voltage limits codified version Luxembourg 2006 OJ L 374 27 12 2006 Council Directive 90 396 EEC of 29 June 1990 on the approximation of the laws of the Member States relating to appliances burning gaseous fuels Luxembourg 1990 OJ L196 26 7 1990 Directive 94 9 EC of the European Parliament an
10. Adjustment and maintenance points must be located outside danger zones It must be possible to carry out adjustment maintenance repair cleaning and servicing operations while equipment is at a standstill If one or more of the above conditions cannot be satisfied for technical reasons measures must be taken to ensure that these operations can be carried out safely In the case of automated equipment and where necessary other equipment a connecting device for mounting diagnostic fault finding equipment must be provided Automated equipment components that have to be changed frequently must be capable of being removed and replaced easily and safely Access to the components must enable these tasks to be carried out with the necessary technical means in accordance with a specified operating method 3 4 2 Access to operating positions and servicing points Equipment must be designed and constructed in such a way as to allow access in safety to all areas where intervention is necessary during operation adjustment and maintenance of the equipment 3 4 3 Isolation of energy sources Equipment must be fitted with means to isolate it from all energy sources Such isolators must be clearly identified They must be capable of being locked if reconnection could endanger people Isolators must also be capable of being locked where an operator is unable from any of the points to which he has access to check that the energy is still cut off In the case of
11. Regulations 1994 Statutory Instrument 1994 No 2063 The Stationery Office The Supply of Machinery Safety Amendment Regulations 2005 Statutory Instrument 2005 No 831 The Stationery Office PD 6686 2006 Guidance on directives regulations and standards related to prevention of fire and explosion in the process industries Directive 1999 92 EC of the European Parliament and Council of 16 December 1999 on the minimum requirements for improving the safety and health protection of workers potentially at risk from explosive atmospheres 15 individual Directive within the meaning of Article 16 1 of Directive 89 391 EEC Luxembourg 1999 OJ No L023 28 01 2000 The Dangerous Substances and Explosives Atmospheres Regulations 2002 Statutory Instrument 2002 No 2776 The Stationery Office Biennial Report on Hydrogen Safety Chapter 3 www hysafe org BRHS BS EN 61508 series of standards Parts 1 to 7 Functional safety of electrical electronic programmable electronic safety related systems Building Regulations 2000 Statutory Instrument 2000 No 2531 as amended The Stationery Office Build Regulations Approved Documents A to P www planningportal gov uk Building Scotland Regulations 2004 Scottish Statutory Instrument 2004 No 406 The Stationery Office Building Scotland Regulations Technical Handbooks www sbsa gov uk tech_handbooks HYPER website www hyperproject eu NATURALHY Project www natu
12. UK version The HYPER project a specific targeted research project STREP funded by the European Commission under the Sixth Framework Programme developed an Installation Permitting Guide IPG for hydrogen and fuel cell stationary applications The IPG was developed in response to the growing need for guidance to foster the use and facilitate installation of these systems in Europe This document presents a modified version of the IPG specifically intended for the UK market For example reference is made to UK national regulations standards and practices when appropriate as opposed to European ones The IPG applies to stationary systems fuelled by hydrogen incorporating fuel cell devices with net electrical output of up to 10 kWel and with total power outputs of the order of 50 kW combined heat electrical suitable for small back up power supplies residential heating combined heat power CHP and small storage systems Many of the guidelines appropriate for these small systems will also apply to systems up to 100 kWel which will serve small communities or groups of households The document is not a standard but is a compendium of useful information for a variety of users with a role in installing these systems including design engineers manufacturers architects installers operators maintenance workers and regulators This report and the work it describes were funded by the Health and Safety Executive HSE Its con
13. and if the explosion risk cannot be entirely eliminated explosion protection measures is referred to as integrated explosion safety Guidance on the integrated explosion safety approach can be found in BS EN 1127 1 2007 which outlines the basic elements of risk assessment for identifying and assessing hazardous situations The standard also specifies general design and construction methods to help designers and manufacturers to achieve explosion safety in the design of equipment protective systems and components 4 4 1 Prevention of explosive atmospheres The first line defence in preventing an explosion is to ensure an explosive atmosphere never exists either as a result of a leak generating an external explosive atmosphere air ingress forming an explosive atmosphere inside the equipment or having a process that operates with gas mixtures in the explosive range Hydrogen due to its low viscosity is particularly prone to leakage from piping vessels etc and therefore special attention should be paid to ensuring gas tight connections in any equipment containing hydrogen The requirements for hydrogen containment and piping are discussed in section 4 2 For processes that operate at sub atmospheric pressures leakage of hydrogen will not be an issue but the possibility of air ingress resulting in the formation of an internal explosive atmosphere needs to be considered Ventilation can be used to prevent small leaks generating an explosive
14. atmosphere by ensuring the escaping gas cannot accumulate to concentrations above the LEL Ventilation is the air movement leading to replacement of a potentially dangerous atmosphere by fresh air The following principles should be used to ensure that any foreseeable release of a dangerous substance cannot accumulate to a concentration that affects the safety of people and property e Wherever possible locate hydrogen storage handling equipment outside e Estimate the maximum foreseeable release rate e Provide adequate high and low ventilation 28 e Beware of low ceilings canopies covers and roofs e Ensure the dilution air is drawn from a safe place e Ensure vents and purges discharge to a safe place e Use computational fluid dynamics CFD for complex ventilation requirements It is always best to locate hydrogen storage handling equipment in the open air however precautions still need to be taken to ensure that a flammable atmosphere cannot accumulate e Avoid the use of low impervious roofs canopies or bulkheads e Avoid locations below eaves or other overhanging structures e Use a suitable non combustible security fence rather than a wall e Ensure adequate high and low level ventilation apertures where a wall around the storage system in unavoidable The size of any foreseeable leak into an enclosed or partially enclosed area should be used as the basis for any calculations of the ventilation requirements The ventilati
15. available hydrogen detection systems shortcomings of current detection techniques are highlighted in Table 4 1 Table 4 1 Indications where commercially available sensors meet or fail to meet current performance targets Criteria Electrochem Catalytic Acoustic Measuring Min Max Min Max Min Max Min Max Min Max Min Max Min Max Range 0 1 10 v x v x v x v v v v v x Temperature Min Max Min Max Min Max Min Max Min Max Min Max Min Max Range c 30 80 x x x x v v x v v x v v Humidity Min Max Min Max Min Max Min Max Min Max Min Max Min Max Range RH 10 98 v x v v v v v v v v v x Response Time i S 2 j d x t 90 s Accuracy 5 v x x v Lifetime yrs 5 x v v v v Due to the considerable differences in the various requirements for indoor applications no sensor type is currently capable of meeting all performance target sets Each detection technology has advantages and disadvantages depending on its intended application When 52 considering a hydrogen detector for a particular application the desired performance capabilities and ambient conditions for the application should be considered H sensors positioning The correct location of reliable sensors is crucial for timely detection and warning of hydrogen 2 5 6 leaks before an explosive mixture is formed Recommended locations for sensors include Evaluate and list all possible leak or spill s
16. equipment capable of being plugged into an electricity supply removal of the plug is sufficient provided that the operator can check from any of the points to which he has access that the plug remains removed After the energy is cut off it must be possible to dissipate normally any energy remaining or stored in the circuits of the equipment without risk to people As an exception to the requirement laid down in the previous paragraphs certain circuits may remain connected to their energy sources in order for example to hold parts to protect information to light interiors etc In this case special steps must be taken to ensure operator safety 3 4 4 Operator intervention Equipment must be so designed constructed and equipped that the need for operator intervention is limited If operator intervention cannot be avoided it must be possible to carry it out easily and safely 3 4 5 Cleaning of internal parts The equipment must be designed and constructed in such a way that it is possible to clean internal parts that have contained dangerous substances or preparations without entering them any necessary unblocking must also be possible from the outside If it is impossible to avoid entering the equipment it must be designed and constructed in such a way as to allow cleaning to take place safely 20 4 SYSTEM SPECIFIC AND SITE CONSIDERATIONS When installing a hydrogen fuel cell system many safety factors need to be taken into account
17. explosive limit LEL up to as much as 75 v v which is the upper explosive limit UEL may propagate a flame The wide range of flammability of hydrogen air mixtures compared to propane and methane air mixtures is in principle a disadvantage There are however only minor differences between the LEL of hydrogen and that of methane or propane The LEL of hydrogen is considered by many experts to have a greater significance in hazard ranking than the width of the fuel s flammable range Furthermore in the case of low momentum releases the dispersion characteristics of hydrogen will make it less likely that a flammable mixture will form 2 3 3 2 Very low ignition energy The energy necessary to initiate a hydrogen air explosion is very small The ignition energy for a 2 1 hydrogen oxygen mixture is only about 0 02 mJ This is less than one tenth that of other fuels such as methane LPG or petrol Even very small sparks such as those produced by wearing certain types of clothing are capable of igniting hydrogen air mixtures and causing an explosion 2 3 3 3 Spontaneous ignition Hydrogen has the possibility to spontaneously ignite on sudden release from pressurised containers 2 3 4 Consequences of a fire explosion 2 3 4 1 Invisible flame Hydrogen burns with an invisible flame making it difficult to detect a hydrogen fire This apparent low emissivity of hydrogen flames total heat flux radiated may reduce the heat transfer by radia
18. hazards or to reduce risks and when appropriate the indication of the residual risks associated with the equipment e The standards and other technical specifications used indicating the essential health and safety requirements covered by these standards e Any technical report giving the results of the tests carried out either by the manufacturer or by a body chosen by the manufacturer or his authorised representative e A copy of the instructions for the equipment e Where appropriate the declaration of incorporation for included partly completed equipment and the relevant assembly instructions for such equipment e Where appropriate copies of the EC declaration of conformity of equipment or other products incorporated into the equipment e Where appropriate for pressure systems documentation relating to compliance with the materials specifications by using materials which comply with harmonised standards by using materials covered by a European approval of pressure equipment materials or by a particular material appraisal e A copy of the EC declaration of conformity e Results of design calculations made examinations carried out etc e Test reports For series manufacture the internal measures that will be implemented to ensure that the equipment remains in conformity with the provisions of the relevant directive s The manufacturer must carry out necessary research and tests on components fittings or the completed equ
19. hurdles for approval Public perception of H2 not good Fear of H2 No standards for installation in place lack of guidance Is it gas or electrical Lack of knowledge within industry What were the challenges hurdles for installation Peripheral trades e g engineers and electricians were not sure of what to do Integrating the system with existing structures What problems were caused by techniques Small issue with lifting gear What problems were caused by administration agencies N A What difficulties did the installer experience Lack of knowledge within industry I T difficulties with German software internet transfer and protocol What difficulties were experienced by the customer None Describe any modifications to the installation process N A In your opinion if a leak were to occur in the system where would it be most likely to occur and what would be the most likely causes of the leak Describe multiple situations if necessary N A 48 8 APPENDIX 3 CE CERTIFICATION 1 Check list The following check list should be used when seeking CE certification Identify the directive s that are applicable to the different components of the fuel cell system Identify the conformity assessment procedure that must be taken for each component being certified whether self declaration or assessment by a Notified Body or a comb
20. increasing other hazards such as those associated with moving gas cylinders e Use the minimum length and size of pipe work that is appropriate e Use the minimum length of high pressure pipe work from the pressure source to the high pressure regulator 22 e Where possible use as small a diameter and operating pressure as possible flow restriction may also be used on high pressure pipe work in order to minimise mass flow of hydrogen and hence the consequences of any unintended releases see Figure 1 e Minimise hydrogen inventories where possible e Minimise the number of joints by using continuous lengths of pipe work wherever practicable e Where possible use fusion joints welded or brazed to join pipe work flange threaded connectors may be used where necessary e Give due consideration to the risk of fatigue due to vibrations in pipes Ensure that the system is leak tested before use in a manner appropriate to hydrogen 39 systems e Use a high pressure relief valve downstream from the high pressure regulator that is able to vent into a safe place where hydrogen gas cannot accumulate but can freely disperse e Suitable isolation valves with locking facilities should be used to enable isolation of sections of pipe work system for routine maintenance and in emergencies e All hydrogen handling equipment and piping shall be identified and appropriately labelled e Carry out appropriate inspections of th
21. it is necessary to certify part or all of a fuel cell system using these directives the full documents should be obtained to assess conformity unless using a third party for certification The process of CE certification is briefly described in section 3 1 1 3 1 DESIGN AND MANUFACTURING REQUIREMENTS 3 1 1 CE certification CE marking is mandatory in the UK for certain product groups which indicates conformity with the essential health and safety requirements set out in a number of EU directives e g machinery 2006 42 EC low voltage 2006 95 EC gas appliances 90 396 EEC ATEX equipment directive 94 9 EC CE conformity marking concerns the design manufacture placing on the market and entry into service of a product The CE marking must be affixed by the manufacturer or his agent established in the EC Depending on the directive concerned certification is either through self declaration or through examination and assessment by a notified body The manufacturer bears the ultimate responsibility for the conformity of the product He has to issue a Declaration of Conformity which includes his identity a list of EU directives he declares compliance with a list of standards the product complies with and a legally binding signature The basis of the conformity assessment is the Technical Construction File also referred to in some directives as the technical file or the technical demonstration which is a compilation of d
22. mechanical transmission devices and partly completed machinery This would not apply to the fuel cell installation itself but may apply to associated equipment required for operating the installation e g a hoist for lifting gas cylinders Prototype equipment does not need to comply with EU Directives and be CE marked Nonetheless it is recommended that the general principles of the essential health and safety requirements are taken into account in the design of a prototype installation 5 1 3 Step 3 other legislation The installation needs to meet legislation dealing with planning approval building regulations see 3 3 1 and fire regulations see 4 6 Installations that are connected to the electrical distribution network for exporting surplus electricity back to the grid will need to meet electrical regulations for interconnectivity of supplies see 4 7 5 1 4 Step 4 installation issues The equipment to be installed and maintained by a competent person At present there is no national scheme in place for training and assessing the competency of persons to install hydrogen systems although some manufacturers do have schemes for training installers and service engineers 5 1 5 Step 5 emergency responders The local fire brigade to be informed of the location and type of installation and given the opportunity to visit the installation Of particular interest would be the location and quantity of any hydrogen stored at the
23. positions of valves for those that are not self indicating o A storage and distribution plan that is legible and drawn approximately to scale showing the intended storage arrangement including the location and dimensions of walkways A list of personnel who are designated and trained to act as a liaison with the emergency services and who are responsible for the following o Aiding the emergency services in pre emergency planning o Identifying the location of compressed gases and cryogenic fluids stored or used o Accessing MSDS 27 o Knowing the site emergency procedures 4 4 EXPLOSION PREVENTION AND PROTECTION For industrial installations DSEAR and the EPS Regulations apply which require an hierarchical approach to explosion prevention and protection DSEAR requires the identification of the explosion hazards and the prevention or protection measures to be employed The measures taken should be appropriate to the nature of the operation being undertaken in order of priority and in accordance with the following basic principles The prevention of the formation of explosive atmospheres or where the nature of the activity does not allow that The avoidance of ignition sources where an explosive atmosphere could exist or If ignition sources cannot be eliminated the employment of measures to mitigate the effects of an ignition This approach to explosion safety using a range of explosion prevention measures
24. rich fuel into a form usable by the fuel cell an electrolyser or a hydrogen storage system tank or transportable cylinders Most fuel cell systems use pure hydrogen or hydrogen rich fuels such as methanol gasoline methane diesel or gasified coal to produce electricity These fuels are passed through onboard internal reformers within the fuel cell itself or though external reformers that extract the hydrogen from the fuel 3 Power conditioning equipment that converts the direct current produced by the fuel cell into alternating current 4 A number of subsystems to manage air water thermal energy and power Although all fuel cell power plants contain these components the assembly of these components into the actual equipment is very important In addition a heat recovery system is typically used in high temperature fuel cell systems that are used for stationary applications where the excess energy in the form of heat can be used to produce steam or hot water or converted to electricity 2 2 HAZARDS ASSOCIATED WITH FUEL CELL INSTALLATION AND OPERATION 2 2 1 Hazards of fuel cells other than hydrogen Many fuel cells use hydrogen produced by the reforming of hydrocarbon fuels other high temperature fuel cells are able to utilise suitable hydrocarbons directly The processing and or use of these hydrocarbon fuels will produce carbon dioxide Appropriate measures such as containment and ventilation should be taken to ensure that any
25. site 37 5 2 OUTLINE APPROVAL CHECKLIST FOR DOMESTIC RESIDENTIAL INSTALLATIONS 5 2 1 Step 1 risk assessment Undertake a risk assessment to identify the hazards and measures to be implemented to eliminate or mitigate their effects For domestic installations at best a fairly basic risk assessment will be required and may not be required at all in some cases e g for an integrated CHP system In these cases it will be sufficient that the equipment is installed according to the manufacturer s instructions as in drawing up these instructions the manufacture will have undertaken a risk assessment Guidance on how to undertake a risk assessment can be found in Appendix 5 5 2 2 Step 2 EU Directives For residential installations there is no legal requirement to use ATEX compliant equipment as the ATEX Directives only apply to the workplace Pressure equipment will still need to comply with the requirements of PED and electrical equipment with LVD and ECM Fuel cells where the primary function is heating will have to comply with GAD and it is also recommended that gas safety regulating and controlling devices on the installation meet the requirements of GAD For further information on these Directives see section 5 1 2 5 2 3 Step 3 other legislation The installation needs to meet national legislation dealing with planning approval building regulations and fire regulations For residential applications they will probably only ne
26. to buoyancy An experimental and modeling programme on the effects of walls and barriers has been carried out within HYPER and details can be found on the project website 4 5 HYDROGEN SENSING As a colourless odourless and tasteless gas hydrogen cannot be detected by human senses therefore means should be provided to detect the presence of hydrogen in locations where leaks and or accumulations may occur When using hydrogen in confined spaces the employment of a hydrogen detection system for early detection of leaks is essential to facilitate the activation of alarms safety operations and where necessary the safe evacuation of people There are numerous hydrogen sensors detectors commercially available operating on various principles 33 When installing a hydrogen gas detection system the following questions need to be considered Which is the most suitable sensing technology What are the appropriate alarm thresholds for the hydrogen detection system g How many sensors are required e0 Where should the sensors detectors be located Consulting relevant standards regulations and guidelines can assist in the choice and correct use of a particular type s of hydrogen detection system most suitable for an application Technical standards for flammable gas detectors have existed for many years although not specifically for hydrogen The most useful among the technical standards are the BS EN 61779 series of standards altho
27. using fuel processing technologies Part 2 Procedures to determine efficiency 42 7 APPENDIX 2 CASE STUDIES The aim of the case studies undertaken as part of the HYPER project was to review and look at a broad range of installations and environments By collecting this information it was hoped to compare best practise and harmonise local technical and non technical variations One of the UK case studies is reproduced below as an example of the type of installation that is currently operating in the UK Further information on the case studies can be found on the HYPER website www hyperproject eu DUDLEY UNITED KINGDOM 1 Details of the Fuel Cell System Application Combined heat and power Customer user Black Country Housing Country England City Town Dudley West Midlands Date 2008 2009 43 Hyper Partner HSE Fuel Type Natural gas YES Hydrogen Other Description Natural Gas Status of development Prototype Verification model YES Serial model Other Description Verification model CE Certification for each component THE WHOLE SYSTEM WAS CE MARKED 1 Component Name CE Certification 1 Stack Yes NO 2 H2 Supply system YES NO 3 Electrical supply inverter Yes NO 4 Control panel YES NO 5 Heat exchanger YES NO 6 Heat Store 7 Electrical supply 8 Batt
28. with a European Directive computational fluid dynamics combined heat and power compressed natural gas Dangerous Substances and Explosive Atmosphere Regulations European Commission essential health and safety requirements European Industrial gases Association Electromagnetic Compatibility Directive European norm standard Equipment and Protective Systems for Use in Potentially Atmospheres Regulations European Union Fuel cell Gas Appliances Directive general fire precautions Health and Safety Executive Health and Safety Laboratory International Electrotechnical Commission Installation Permitting Guidance International Standards Organisation lower explosion limit 58 Explosive LOC LPG LVD MCFC MSDS NASA NFPA PACF PED PER PEMFC PFP SOFC STREP UEL limiting oxygen concentration liquefied petroleum gas Low Voltage Directive molten carbonate fuel cell materials safety data sheet National Aeronautics and Space Administration National Fire Protection Association phosphoric acid fuel cell Pressure Equipment Directive Pressure Equipment Regulations polymer electrolyte membrane fuel cell process fire precautions solid oxide fuel cell Specific Targeted Research project upper explosion limit 59 12 APPENDIX 7 REFERENCES Installation Permitting Guidance for hydrogen and fuel cell stationary applications HYPER Project www hyperproject eu BS EN 62282 3
29. without damage During the transportation of the equipment and or its component parts there must be no possibility of sudden movements or of hazards due to instability as long as the equipment and or its component parts are handled in accordance with the instructions Where the weight size or shape of equipment or its various component parts prevents them from being moved by hand the equipment or each component part must either be fitted with attachments for lifting gear or be designed so that it can be fitted with such attachments or be shaped in such a way that standard lifting gear can easily be attached Where equipment or one of its component parts is to be moved by hand it must e either be easily moveable or be equipped for picking up and moving safely Special arrangements must be made for the handling of tools and or machinery parts which even if lightweight could be hazardous 3 3 REGULATORY APPROVAL CONSIDERATIONS The approval process may depend on whether the installation is in a work environment industrial or a residential environment and the fact that different authorities have responsibility for the industrial and residential premises Furthermore the process may depend on the fuel used As some fuel cells especially those providing combined heat and power operate on natural gas these fuel cells may qualify under existing regulations and be treated similarly to a gas boiler For fu
30. 0 2003 Electrical apparatus for explosive gas atmospheres Part 10 Classification of hazardous areas ANSI AIAA G 095 2004 Guide to Safety of Hydrogen and Hydrogen Systems American National Standards Institute ANSI American Institute of Aeronautics and Astronautics BS 5925 1991 Code of Practice for ventilation principles and designing for natural ventilation PD CEN TR 15282 2006 Guidance on inerting for the prevention of explosions EN 60079 0 2004 Electrical apparatus for explosive gas atmospheres Part 0 General requirements EN 60079 14 2008 Explosive atmospheres Part 14 Electrical installations design selection and erection EN 60079 17 2007 Explosive atmospheres Part 17 Electrical installations inspection and maintenance EN 60079 19 2007 Explosive atmospheres Part 19 Equipment repair overhaul and reclamation 62 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 EN 13463 1 2009 Non electrical equipment for potentially explosive atmospheres Part 1 Basic method and requirements EN 15198 2007 Methodology for the risk assessment of non electrical equipment and components for intended use in potentially explosive atmospheres PD CLC TR 50404 2003 Electrostatics Code of practice for the avoidance of hazards due to static electricity EN 14797 2006 Explosion venting devices EN 14994 2007 Gas explosion venting prote
31. 1 7 Protection against fire and explosion hazards The manufacturer should safeguard against risk of fire and explosion 12 For fuel cell components for use in potentially explosive atmospheres the Equipment and protective Systems for Use in Potentially Explosive Atmospheres EPS Regulations 1996 apply The ATEX Workplace Directive 99 92 EC implemented in the UK by the Dangerous Substances and Explosive Atmospheres Regulations DSEAR 2002 will also apply Although DSEAR does not specifically require the production of an explosion protection document as required by the ATEX Workplace Directive the key requirement of the Regulations is that risks from dangerous substances e g flammable gases are assessed and controlled The DSEAR and EPS Regulations only apply to workplaces and thus would not be applicable to domestic installations 3 1 8 Protection against pressure related hazards The Pressure Equipment Regulations PER 1999 apply to any equipment that could contain pressures in excess of 0 5 bar The Regulations require the following aspects to be addressed Strength of equipment Provisions to ensure safe handling and operation Means of examination Means of draining and venting Materials for pressure vessels Wear Assemblies Provisions for filling and discharge Protection against exceeding the allowable limits of pressure equipment Safety accessories Manufacturing procedures Marking and labelling O
32. 6 Low Voltage Directive LVD The Electrical Equipment Safety Regulations Applies to electrical equipment designed for use with a voltage rating of between 50 and 1 000 V for AC and between 75 and 1 500 V for DC Electromagnetic Compatibility Directive EMC The Electromagnetic Compatibility Regulations Applies to commercially available equipment or combinations of equipment made into a single unit intended for an end user and liable to generate electromagnetic disturbance or the performance of which is liable to be affected by such disturbance Gas Appliances Directive GAD The Gas Appliances Safety Regulations Applies to appliances burning gaseous fuels used for cooking heating hot water production refrigeration lighting or washing and having where applicable a normal water temperature not exceeding 105 C Note though fuel cells do not burn gaseous fuels and should be excluded from the scope of the Directive guidance issued on what appliances are covered by the Directive includes fuel cells where the primary function is heating The Directive also covers such components as safety regulating and controlling devices which may fitted in the gas side of a fuel cell or a reformation unit for generating hydrogen Machinery Directive Supply of Machinery Safety Regulations Applies to machinery interchangeable equipment safety components lifting accessories chains ropes and webbing removable
33. 7 Electrical and non electrical equipment appropriate for use in the different areas of the workplace should be determined once the hazardous areas have been identified and classified The EN 60079 series of standards specifies the requirements and testing of electrical equipment for use in the different zones Part 0 specifies the general requirements for the construction testing and marking of electrical apparatus and components intended for use in hazardous areas where explosive gas air mixtures exist under normal atmospheric conditions Part 14 gives the specific requirements for the design selection and erection of electrical installations in explosive gas atmospheres These requirements are in addition to those for installations in non hazardous areas Part 17 covers the maintenance of electrical installations in hazardous areas and Part 19 the repair and overhaul for apparatus used in explosive atmospheres Non electrical equipment is covered by the BS EN 13463 series of standards with Part 1 specifying the basic method and requirements for the design construction testing and marking of equipment Methodology for the risk assessment of non electrical equipment for use in potentially explosive atmospheres is given in BS EN 15198 2007 31 The hazardous area classification should also be used to ensure that suitable controls are placed on all other foreseeable sources of ignition including hot work smoking vehicles mobile
34. 995 applies to appliances burning gaseous fuels used for cooking heating hot water production refrigeration lighting or washing and having where applicable a normal water temperature not exceeding 105 C It also specifies requirements for certain fittings including safety regulating and controlling devices and sub assemblies For the purposes of this directive a gaseous fuel means any fuel that is in a gaseous state at a temperature of 15 C at a pressure of 1 bar Though fuel cells do not burn gaseous fuels and should be excluded from the scope of the Directive guidance issued on what appliances are covered by the Directive 18 includes fuel cells where the primary function is heating The essential safety requirements of the Directive could also be applied to certain components of the installation e g a reformation unit for generating hydrogen and safety regulating and control devices Hydrogen fuel cell installations would also need to comply with the relevant parts of the Supply of Machinery Safety Regulations the Electrical Equipment Safety Regulations 1994 the Electromagnetic Compatibility Regulations 2006 as well as EU directives and UK legislation covering general health and safety Further information on the procedures for demonstrating conformity with EU directives and obtaining CE marking for equipment is given in 3 1 and Appendix 3 3 4 OPERATIONAL MAINTENANCE CONSIDERATIONS 3 4 1 Equipment maintenance
35. Fuel cell technologies Part 3 1 Stationary Fuel Cell Power Systems Safety BS ISO 16110 1 2007 Hydrogen generators using fuel processing technologies Safety Supply of Machinery Safety Regulations The Gas Appliances Safety Regulations 1995 EN 50465 2008 Gas appliances Fuel cell gas heating appliance nominal heat input up to 70kW BS EN 13611 2007 Safety and control devices for gas burners and gas burning appliances general requirements BS EN 161 2002 Automatic shut off valves for gas burners and gas appliances BS EN 298 2003 Automatic gas burner control systems for gas burners and gas burning appliances with or without fans BS EN 437 2003 Test gases Test pressures Appliance categories BS EN 483 1999 Gas fired central heating boilers Type C boilers of nominal heat input not exceeding 70 kW BS EN 677 1998 Gas fired central heating boilers Specific requirements for condensing boilers with a nominal heat input not exceeding 70 kW BS EN ISO 12100 1 2003 Safety of machinery Basic concepts general principles for design Basic terminology methodology BS EN ISO 12100 2 2003 Safety of machinery Basic concepts general principles for design Technical principles BS EN 50165 1997 Electrical equipment of non electric appliances for household and similar purposes Safety requirements BS EN 60079 14 2008 Explosive atmospheres Electrical inst
36. Hydrogen systems installation BS EN 61779 series Parts 1 to 5 Electrical Apparatus for the Detection and Measurement of Flammable Gases BS EN 60079 29 1 2007 Explosive atmospheres Gas detectors Performance requirements of detectors for flammable gases BS EN 60079 29 2 2007 Explosive atmospheres Gas detectors Selection installation use and maintenance of detectors for flammable gases and oxygen BS EN 62282 3 3 2008 Fuel cell technologies Part Stationary fuel cell power systems Installation EN 60079 10 2003 Electrical apparatus for explosive gas atmosphere Classification of hazardous areas HSG243 Fuel cells Understand the hazards control the risks HSE Books An Installation Guide for Hydrogen Fuel Cells and Associated Equipment Draft UK Hydrogen Association CGA G 5 4 Standard for Hydrogen Piping Systems at Consumer Sites Compressed Gas Association CGA G 5 5 Hydrogen Vent Systems Compressed Gas Association NFPA 853 2007 Standard for the Installation of Stationary Fuel Cell Power Plants National Fire Protection Association ASME B31 Hydrogen Piping and Pipeline Project Team American Society of Mechanical Engineers 40 Hydrogen storage BS EN ISO 11114 1 1998 Transportable gas cylinders Compatibility of cylinder and cylinder valve with gas contents Metallic materials BS EN ISO 11114 4 2005 Transportable gas cy
37. INTRODUCTION AND SCOPE 1 1 HOW THE DOCUMENT WAS PRODUCED The HYPER project started on 1 November 2006 and ended in February 2009 The work programme of the HYPER project was structured around the development of an installation permitting guide IPG which includes 7 An assessment of current knowledge on installation requirements of small stationary hydrogen and fuel cell systems Detailed case studies of representative installations 7 Modelling and experimental risk evaluation studies to investigate fire and explosion phenomena This specific targeted research project STREP was funded by the European Commission under the Sixth Framework Programme and contributes to the Implementation of the Thematic Priority Sustainable Energy Systems Contract No 039028 The IPG was developed in response to the growing need for guidance to facilitate small hydrogen and fuel cell stationary installations in Europe This report is a revised version of the IPG intended for the UK market reference being made to UK national regulations and standards as opposed to European as appropriate 1 2 HOW TO USE THE DOCUMENT This document is not a standard but is a compendium of useful information for a variety of users with a role in installing these systems including Design engineers e Manufacturers e Architects e Installers Operators Maintenance workers Regulators The document is organised as follows
38. allations design selection and erection BS EN 60079 17 2007 Explosive atmospheres Electrical installations inspection and maintenance BS EN 60079 19 2007 Explosive atmospheres Equipment repair overhaul and reclamation BS EN 60204 1 2006 Safety of machinery Electrical equipment of machines General requirements 39 Hydrogen system specifications BS EN 60335 1 2002 Specification for safety of household and similar electrical appliances General requirements BS EN 60529 1992 Specification for degrees of protection provided by enclosures IP code BS EN 60730 series Automatic electrical controls for household and similar use BS EN 60950 1 2006 Information technology equipment Safety General requirements BS EN 61000 6 2 2005 Electromagnetic compatibility EMC Generic Standards Immunity for industrial environments BS EN 61000 6 4 2001 Electromagnetic compatibility EMC Generic standards Emission standard for industrial environments ANSI AIAA G 095 2004 Guide to Safety of Hydrogen and Hydrogen System American National Standards Institute American Institute of Aeronautics and Astranautics Fire safety Regulatory Reform Fire Safety Order 2005 Fire Scotland Act 2005 PD 6686 2006 Guidance on directives regulations and standards related to prevention of fire and explosion in the process industries
39. ally require a hydrogen supply of high purity as their performance and operational life can be adversely affected by even trace impurities in the hydrogen supply This is less so for SOFC ISO standard ISO 14687 1999 deals with product specification for hydrogen fuel The European Industrial Gases Association EIGA document on gaseous hydrogen stations IGC Doc 15 06 E contains some guidance on the operation of purification systems 4 2 HYDROGEN CONTAINMENT AND PIPING Measures to prevent the release of dangerous substances should be given the highest priority The likelihood of a leak occurring can be minimised by using high quality engineering Particular attention should be paid to the design installation operation and maintenance of hydrogen handling equipment in order to reduce the likelihood and size of any leak The following points should be taken into account as recommended best practices e Ensure that the storage equipment pipe work and connections conform to an approved standard for hydrogen equipment e Ensure that maintenance work if effectively controlled and is only carried out by authorised competent people e Minimise the frequency with which connections are made and broken e For gaseous supply use appropriate refillable stationary storage in preference to regularly replacing large numbers of separately connected cylinders e Use the minimum amount of storage that is practical without disproportionately
40. an appropriate dedicated unoccupied storage building in an appropriately ventilated enclosure or in a purpose designed indoor or underground facility and should conform to recognised guidance Requirements specific to commercial industrial premises The fuel cell and any associated equipment shall be suitably protected against unauthorised access interference vandalism or terrorist attack commensurate with the location and installation environment Any security arrangements shall not compromise the requirement for effective ventilation The fuel cell and associated equipment shall be suitably located to allow service maintenance and fire department emergency access and shall be supported anchored and protected so that they will not be adversely affected by weather conditions rain snow ice freezing temperatures wind seismic events and lightning or physical damage Furthermore the placing of any components of the fuel cell system should not adversely affect required building exits under normal operations or in emergencies If practicable the installation should be located in a normally unoccupied room built to appropriate fire resistance standard and within an appropriate fire resisting and non combustible enclosure Congestion blockages and obstructions should be kept to an absolute minimum in the room as they may enhance flame acceleration in the event of an accident The room in which the fuel cell and associated equipment are lo
41. and hence the potential consequences of an ignition Ideally alarms should be audible and visible Automatic corrective actions are actions that can be automatically triggered including forced ventilation isolation of electrical components isolation of hydrogen storage and auto shutdown Hydrogen sensors maintenance and calibration The performance of most sensors detectors deteriorates with time the rate depending on the type of sensor detector and the operating conditions e g dusty corrosive or damp environment Functioning must be checked with the frequency recommended by the manufacturer Checking should include appropriate cleaning especially the head of the detector to allow gas to reach the sensitive element regular inspections for possible malfunctions visible damage or other deterioration that a zero reading is obtained in a clean atmosphere that a correct response is obtained for exposure to a known concentration that if data logging is required the logging period is appropriate for all data points over the required measurement time and can be stored in memory the battery level for portable instruments The best means to determine maintenance intervals for a sensor detector is based on experience learned from use For new installations it may be wise to carry out maintenance frequently at first perhaps weekly increasing the time intervals to perhaps monthly as confidence grows on the basis of
42. ard identification process required by DSEAR would serve as a useful model for assessing the safety requirements of domestic installations The Pressure Equipment Regulations PER 1999 implementing the Pressure Equipment Directive 97 23 EC apply to the design manufacture and conformity assessment of pressure equipment that is subjected to an internal pressure greater than 0 5 bar above atmospheric pressure It covers equipment such as pressure vessels heat exchangers steam generators boilers piping safety devices and pressure accessories Thus some of the components of a hydrogen fuel cell installation may fall within the scope of the Directive although these are usually bought on the market as certified products Each affected item of pressure equipment has to be assigned into a hazard category according to specific criteria which then determines the overall essential safety requirements to be met Depending on the categories different conformity assessment options are permitted to demonstrate compliance by variants on quality assurance direct inspection or surveillance of testing by the Notified Body It is recommended that advice from consultants who specialise in pressure systems be sought in selecting the most appropriate conformity option as an inappropriate choice can lead to unnecessary delays and costs in demonstrating compliance The Gas Appliances Directive implemented in the UK The Gas Appliances Safety Regulations 1
43. associated with the installation of the equipment start up and shutdown of the equipment delivery of consumables e g gas cylinders and the maintenance and repair of the equipment Guidance on how to undertake a risk assessment can be found in Appendix 5 For workplaces it is a legal requirement under DSEAR for the employer to identify the fire and explosion hazards classify areas where explosive atmospheres may exist evaluate the risks and specify measures to prevent or where this is not possible mitigate the effects of an ignition Further information on explosion control and mitigation measures is given in 4 4 5 1 2 EU Directives The equipment used in the installation must comply with the essential health and safety requirements of all applicable EU Directives Compliance confirmed by the CE marking for each applicable Directive see 3 1 and Appendix 3 For a hydrogen fuel cell installation the applicable Directives and the UK implementing regulations are ATEX Equipment Directive EPS Regulations Applies to any equipment electrical or non electrical or protective system designed manufactured or sold for use in a potentially explosive atmosphere Pressure Equipment Directive PED Pressure Equipment Regulations Applies to the design manufacture and conformity assessment of pressure equipment with a maximum allowable pressure greater than 0 5 bar above atmospheric over the temperature range it is designed for 3
44. carbon dioxide effluent stream is effectively discharged and does not produce an asphyxiation risk Natural gas methane is lighter than air and will tend to diffuse upwards but at a much slower rate than hydrogen The explosion limits for natural gas 5 15 v v are also much narrower than hydrogen The characteristics of both fuels should be considered for any dual fuel systems The pipe work and equipment used to supply natural gas should also be suitable and designed to an appropriate standard Liquefied petroleum gas LPG is considerably heavier than air especially when cold for example when taken directly from a liquid storage vessel In the event of a leak LPG vapour will usually percolate downwards and may accumulate on the floor or in low lying sumps rapidly producing a flammable atmosphere Mixtures containing 2 10 v v LPG in air will readily ignite and explode The significant differences in the buoyancy and dispersion characteristics of the two fuels should be carefully considered in systems where LPG and 4 hydrogen may both be present The pipe work and equipment used to store and supply LPG fuel should also be suitable and be designed to an appropriate standard Methanol can be used directly by some types of fuel cell This fuel has some hazards that demand particular attention In addition to being a highly flammable liquid methanol is also toxic by inhalation ingestion and notably by skin absorption Appropria
45. cated in domestic dwellings in commercial premises buildings or outside in the open air 4 3 1 General requirements for both domestic residential and commercial industrial installations The following general requirements apply to all systems whatever their location and should be taken into account in assessing that the risk is acceptable and has been reduced to as low as is reasonably practicable The installation should be placed on firm foundations capable of supporting it Ensure that any area enclosure or housing etc into which hydrogen may leak is designed to prevent the gas becoming trapped and is equipped with effective high and low level ventilation openings The installation components in particularly vent or exhaust outlets should be sited giving due attention to adjoining doors windows outdoor air intakes and other openings into buildings Air intakes shall be located in such a way that the fuel cell is not adversely affected by other exhausts gases or contaminants Exhaust outlet s should not be directed onto walkways or other paths of pedestrian travel Security barriers fences landscaping and other enclosures should not affect the required flow into or exhaust out of the installation Any vents from pressure relief valves or bursting joints etc should be piped to a safe area and any points of possible leakage should be in an area where any gas cannot accumulate or is freely ventilated In addition care sho
46. cated shall provide a minimum of 30 minutes fire resistance and be fitted with a suitable fire detection and alarm system The installation should not be located in areas that are used or are likely to be used for combustible flammable or hazardous material storage Any potential sources of ignition such as non flameproof electrical light fittings should be located well below any equipment from which hydrogen may leak and not immediately below horizontal bulkheads or impervious ceilings under which hydrogen may accumulate For workplaces it is a legal requirement under DSEAR for the employer to identify fire and explosion hazards classify areas where explosive atmospheres may exist evaluate the risks and specify of measures to prevent or where this is not possible mitigate the effects of an ignition All equipment electrical or mechanical within the identified hazardous zone shall be CE certified Whenever reasonably practicable the fuel cell and other hydrogen handling equipment shall be located at the highest level within the enclosure and physically isolated from any electrical equipment that is not ATEX complaint or other potential sources of ignition Gas tight compartments bulkheads and ventilation should as far as possible be used to reduce the likelihood of leaking hydrogen reaching potential ignition sources 26 4 3 3 Unless compliant with the EPS Regulations the installation should be located away from areas wh
47. considered as suitable and sufficient if it has e correctly identified all the hazards e disregarded inconsequential risks and those trivial risks associated with life in general e determined the likelihood of injury or harm arising 56 e identified those who may be at particular risk such as pregnant elderly or disabled persons e taken into account any existing control measures e identified any specific legal duty or requirement relating to the hazard e provided sufficient information to decide upon appropriate control measures taking into account the latest scientific developments and advances e enabled the remedial measures to be prioritised e will remain valid for a reasonable period of time A free download of an HSE leaflet giving more detail on the five steps to risk assessment is available at www hse gov uk pubns indg163 pdf Further assistance in producing risk assessments is available in books videos and training sessions Many consultancy organisations exist that can assist with or prepare risk assessments for their clients 57 AFC ATEX BRHS CE CFD CHP CNG DSEAR EC EHSR EIGA EMC EN EPS EU FC GAD GFP HSE HSL IEC IPG ISO LEL 11 APPENDIX 6 ABBREVIATIONS alkaline electrolyte fuel cell ATmosph res EXplosibles Explosive atmospheres Biennial Report on Hydrogen Safety Conformit Europ enne European Conformity the marking used to show conformity
48. ctive systems NFPA 68 Standard on explosion protection by deflagration venting 2007 Edition National Fire Protection Association EN 14373 2005 Explosion suppression systems prEN 15098 Explosion isolation systems EN 12874 2001 Flame arresters Performance requirements test methods and limits for use EN 14460 2006 Explosion resistant equipment BS EN 61779 series Parts 1 to 5 Electrical Apparatus for the Detection and Measurement of Flammable Gases Biennial Report on Hydrogen Safety BRHS Chapter 6 www hysafe org BRHS Council Directive concerning the minimum safety and health requirements for the workplace first individual directive within the meaning of Article 16 1 of Directive 89 391 EEC Luxembourg 1989 OJ L 183 29 6 1989 Regulatory Reform Fire Safety Order 2005 Statutory Instrument 2005 No 1541 The Stationery Office Fire Scotland Act 2005 Scottish Statutory Instrument 2005 No 207 The Stationery Office BS 9999 2008 Code of practice for fire safety in the design management and use of buildings Technical Note G83 1 1 Recommendations for the connection of small scale embedded generators up to 16A per phase in parallel with public low voltage distribution networks The Energy Networks Association ENA 63 Published by the Health and Safety Executive 06 09 Health and Safety Executive Installation permitting guidance for hydrogen and fuel cell stationary applications
49. d from the ambient air around the fuel cell In some cases where hydrogen is produced by electrolysis the oxygen co produced may be used in the fuel cell Fuel cells can be loosely grouped into those with acidic electrolytes those where the electrolyte is alkaline and cells that operate at very high temperatures Successful examples of acidic electrolyte fuel cells are the proton exchange membrane or polymer electrolyte membrane fuel cells PEMFCs that use a solid polymer as an electrolyte and porous carbon electrodes containing a platinum catalyst and the phosphoric acid fuel cells PAFCs that use liquid phosphoric acid as an electrolyte the acid is contained in a Teflon bonded silicon carbide matrix and porous carbon electrodes containing a platinum catalyst PEMFCs are generally designed to be operated at lower temperatures although some may operate at around 80 C while PAFCs typically operate at temperatures between 150 C to 200 C Alkaline electrolyte fuel cells AFCs use an aqueous solution of potassium hydroxide as the electrolyte and can use a variety of non precious metals as a catalyst at the anode and cathode Most AFCs operate at temperatures of between 100 C and 250 C but new designs operate at lower temperatures of between 20 C to 70 C High temperature fuel cells include molten carbonate fuel cells MCFCs and solid oxide fuel cells SOFCs MCFCs use an electrolyte composed of a molten carbonate salt mixture susp
50. d of the Council of 23 March 1994 on the approximation of the laws of Member States concerning equipment and protective systems intended for use in potentially explosive atmospheres Luxembourg 1994 OJ L100 19 04 1994 The Gas Appliances Safety Regulations 1995 Statutory Instrument 1995 No 1629 The Stationery Office The Equipment and Protective System Regulations 1996 Statutory Instrument 1996 No 192 The Stationery Office Directive 97 23 EC of the European Parliament and of the Council of 29 May 1997 on the approximation of laws of the Member States concerning pressure equipment Luxembourg 1997 OJ L181 09 07 1997 The Pressure Equipment Regulations 1999 Statutory Instrument 1999 No 2001 The Stationery Office 60 20 21 22 23 24 25 26 21 28 29 30 31 32 33 Directive 2004 108 EC of the European parliament and of the Council of 15 December 2004 on the approximation of the laws of the Member States relating to electromagnetic compatibility and repealing Directive 89 336 EEC Luxembourg 2004 OJ L390 31 12 2004 Electromagnetic Compatibility EMC Regulations 2006 Statutory Instrument 2006 No 3418 The Stationery Office The Electrical Equipment Safety Regulations 1994 Statutory Instrument 1994 No 3260 The Supply of Machinery Safety Regulations 1992 Statutory Instrument 1992 No 3073 The Stationery ffice The Supply of Machinery Safety Amendment
51. d thermal conductivity detectors TCD are mainly used in the industries where the hydrogen risk is present The metal oxide semi conductor based sensor MOS is most often used in research laboratories whereas the MEMS micro electro mechanic system are used in the aeronautic and aerospace industries Other less common but still commercially available sensors include gas field effect GFE type sensors and acoustic sensors The various types of hydrogen detection technologies currently in use are described in detail in Chapter 5 of the HySafe Biennial Report on Hydrogen Safety BRHS together with a description of emerging technologies for hydrogen detection Some important factors to consider in the selection of a hydrogen sensor include accuracy measuring range response time ambient working conditions lifetime and stability see ISO TR15916 A market investigation on the performance of commercially available sensors has been performed see HYSAFE deliverable D5 4 the investigation was based on the technical information product specifications datasheets made available by manufacturers Some general hydrogen performance targets for hydrogen safety sensors are given below Measurement range 0 1 10 H in air e Operating temperature 30 80 C Humidity range 10 98 e Response time t 90 lt 1 sec e Accuracy 5 Lifetime 5 yrs Considering these performance targets and the capabilities of commercially
52. drogen against two other widely used fuels natural gas and LPG is given in Table 1 Table 1 Characteristics of hydrogen dry natural gas and gaseous propane Property Dry natural gas LPG Hydrogen methane propane Density Kg m 0 65 1 88 0 090 Diffusion coefficient in air cm s 0 16 0 12 0 61 Viscosity g cm s x 10 0 651 0 819 0 083 Ignition energy in air mJ 0 29 0 26 0 02 Ignition limits in air vol 5 3 15 0 2 1 9 5 4 0 75 0 Auto ignition temperature C 540 487 585 Specific heat at constant pressure 2 22 1 56 14 89 J gK Flame temperature in air C 1875 1925 2045 Quenching gap mm 2 2 0 6 Thermal energy radiated from 10 33 10 50 5 10 flame to surroundings Detonability limits vol in air 6 3 13 5 3 1 7 0 13 65 Maximum burning velocity m s 0 43 0 47 2 6 at normal temperature and pressure 1 atmosphere and 20 C 2 3 1 Propensity to leak 2 3 1 1 Low viscosity Hydrogen gas has a very low viscosity and so it is very difficult to prevent hydrogen systems from developing leaks Pipe work that was leak tight when pressure tested with nitrogen will often be found to leak profusely when used on hydrogen duty Hydrogen leakage through welds flanges seals gaskets etc is an important consideration and an important design and operational issue for hydrogen systems The use of suitable sealing interfaces a
53. e system at suitable regular intervals and record the results e Review the operation and maintenance history at suitable intervals When high pressure storage is used it should be designed and built to an appropriate design code or standard and located in a secure open air compound Measures appropriate to the location should be taken to prevent unauthorised access vandalism and impact from vehicles Cryogenic hydrogen storage installations should be constructed to an appropriate code and located in a suitable open air position and not within an occupied building Low temperature storage installations should incorporate suitable measures to prevent oxygen rich liquid air a powerful oxidising agent from condensing on uninsulated surfaces exposed to liquid hydrogen temperatures To avoid the risk from fire potentially flammable materials including asphalt and tarmac should not be present beneath pipe work where condensation may occur Only appropriate pipe work and fittings for the supply of hydrogen should be used Cupro nickel and stainless steel are preferred materials for high pressure pipe work whereas copper can be used for lower pressures All pipe work joints should be brazed or welded where possible Flanged or screwed joints may be used where necessary Suppliers should be able to provide information on the operating parameters of pipe work and fitting and the standards used for their manufacture Compression joints are
54. ed to comply with the building regulations see 3 3 1 These as well as dealing with construction requirements of the building also deal with issues including fire safety ventilation sound insulation and energy efficiency Installations that are connected to the electrical distribution network for exporting surplus electricity back to the grid will need to meet national electrical regulations for interconnectivity of supplies see 4 7 5 2 4 Step 4 installation issues The equipment to be installed and maintained by a competent person At present there is no national scheme in place for training and assessing the competency of persons to install hydrogen systems although some manufacturers do have schemes for training installers and service engineers 5 2 5 Step 5 emergency responders The local fire brigade to be informed if there will be hydrogen stored e g gas cylinders at the premises It is also recommended that the property insurers are informed of the installation 38 6 APPENDIX 1 USEFUL CODES AND STANDARDS Table 1 1 lists useful codes and standards Codes and standards are under continuous update and review For the latest status of the hydrogen and fuel cell codes and standards the user is referred to http www fuelcellstandards com Table 1 1 Listing of useful codes and standards Application topic Applicable codes and standards Hydrogen system specifications BS EN 62282 3 1 2007
55. el cells operating on other fuels in particular hydrogen which is not currently covered by existing regulations as a fuel 16 gas more time may be required for preparing technical information for the approval and for the review of that information 3 3 1 Building codes and regulations Building codes and regulations describe a set of rules which specify an acceptable level of safety for constructed objects both buildings and non building structures Their requirements cover issues such as e Design and construction to ensure structural stability of the building and adjoining buildings e Fire safety means of escape prevention of internal and external fire spread and access and facilites for the fire services e Preparation and resistance to moisture e Control of toxic substances e Resistance to the passage of sound e Ventilation e Hygiene safety and provision of sanitary and washing facilites e Drainage and waste disposal e The use of combustion appliances and fuel storage e Protection from falling collision and impact e The conservation of fuel and power e Access to and use of the building e Safety relating to windows impact opening and cleaning e Electrical safety Some buildings may be exempt from these controls such as temporary buildings buildings not frequented by people unless close to a building that is small detached buildings such as garages garden storage sheds and huts and simple extensi
56. ember states to assist in preparing risk assessments These include guidance books videos training sessions and consultancy services These can be found using an internet search engine with the key words risk assessment Further guidance on performing a risk assessment is given in Appendix 5 3 1 4 Protection against mechanical hazards The Machinery Directive requires the following aspects to be considered e Risk of loss of stability e Risk of break up during operation e Risks due to falling or ejected objects e Risks due to surfaces edges or angles e Risks related to combined equipment e Risks related to variations in operating conditions e Risks related to moving parts e Choice of protection against risks arising from moving parts e Risks of uncontrolled movements 3 1 5 Protection against electrical hazards The electrical equipment together with its component parts should be made in such a way as to ensure that it can be safely and properly assembled and connected The following should be addressed e Protection against hazards arising from the electrical equipment e Protection against hazards which may be caused by external influences on the electrical equipment e Electricity supply e Static electricity e Electromagnetic compatibility 3 1 6 Protection from flammable gas appliance hazards The Gas Appliances Safety Regulations require the possibility of unburned gas release to be considered 3
57. en in Appendix 1 A further useful source of information is the BSI published document PD 6686 2006 It discusses the EU and UK legislation intended to minimize the risk of fire and explosion in the process industries and provides a comprehensive guide to the standards draft standards and other documents that contain technical practical and organizational information to ensure compliance 3 1 2 Compliance with EC directives The manufacturer of a fuel cell and its components or their authorised representative must ensure that the relevant EC directives are complied with Compliance with these directives is mandatory in the UK however taking into account the state of the art demonstration models etc it may not be possible to meet all the objectives set In that event the equipment must as far as possible be designed and constructed with the purpose of approaching the objectives detailed 11 in any relevant directive s Table 2 gives a list of relevant directives An outline of what has to be addressed is given in the sections below 3 1 3 Risk Assessment The manufacturer of a fuel cell and its components or their authorised representative must ensure that a risk assessment is carried out in order to determine the health and safety requirements that apply to the equipment The equipment must then be designed and constructed taking into account the results of the risk assessment There are technical resources available in many EU m
58. ended in a porous chemically inert ceramic lithium aluminium oxide and operate at 650 C and above SOFCs use a hard non porous ceramic as the electrolyte and operate usually at around 1 000 C Ongoing research is aimed at reducing this operating temperature down to 550 700 C 2 1 2 Components of a fuel cell system All fuel cells work broadly on the same principle Hydrogen or a hydrogen rich fuel is fed to the anode where a catalyst separates hydrogen s negatively charged electrons from positively charged ions protons At the cathode oxygen combines with electrons and in some cases with species such as protons or water resulting in water or hydroxide ions respectively For polymer electrolyte membrane and phosphoric acid fuel cells protons move through the electrolyte to the cathode to combine with oxygen and electrons to generate water The electrons from the anode side of the cell cannot pass through the membrane to the positively charged cathode so they must travel around it via an electric circuit to reach the other side of the cell This movement of electrons is an electric current The design of fuel cell systems can vary significantly depending on the fuel cell type and application However most fuel cell systems consist of four basic components 1 A set or stack of individual cells consisting of an electrolyte sandwiched between two thin electrodes 2 A fuel cell processor reformer that converts the hydrogen
59. ent There are a number of methods used to seal the vents such as thin membranes bursting discs lightweight covers held in place by magnetic fasteners and spring loaded doors The opening pressure of the covers and the size of the vents are chosen to give explosion pressures below that which would damage the equipment It may however be acceptable to allow some damage to the equipment e g bowing of panels provided it does not result in damage to the adjacent area or injuries to nearby personnel It should also be ensured that the explosion is vented to safe areas so it causes no damage or injuries BS EN 14797 2006 BS EN 14994 2007 and NFPA 6857 provide guidance on the design of explosion relief systems and the methods of available for vent sizing 4 4 3 2 Explosion suppression Explosion suppression is achieved by injecting a suppressant agent either water or a liquid or powder suppressant into a developing explosion to quench it before the maximum explosion pressure is attained Suppressing hydrogen explosions is particularly challenging due to the high flame speeds of hydrogen explosions Basic requirements for the design and application of explosion suppression systems are given in BS EN 14373 2005 32 4 4 3 3 Isolation systems Explosion isolation is a technique that prevents an explosion pressure wave and a flame complete isolation or only a flame partial isolation from propagating via connecting pipes or ducts into othe
60. ere potentially explosive atmospheres may be present The ventilation exhaust or other sources of emission that may contain dangerous substances must be released to a safe place An appropriate hazardous zone should be identified around any foreseeable release point The following additional factors should be taken into account in assessing that the risk is acceptable and has been reduced to as low as is reasonably practicable smoking permitted areas uncontrolled public areas security barriers emergency exits Emergency planning It is recommended that an emergency plan should be in place wherever compressed gaseous or cryogenic fluids are produced handled or stored This emergency plan should include the following The type of emergency equipment available and its location A brief description of any testing or maintenance programs for the available emergency equipment An indication that hazard identification labeling is provided for each storage area The location of posted emergency procedures A list including quantities of compressed gases and cryogenic liquids and their materials safety data sheets MSDS or equivalent A facility site plan including the following information o Storage and use areas o Maximum amount of each material stored or used in each area o Range of container sizes o The location of gas and liquid conveying pipes o Locations of emergency isolation and mitigation valves and devices o On and off
61. ery Pack Which directives were used Hazop performed and Risk Assessment with HSE Planning authority consulted but they said it was outside their control Building control advised to treat it as an outside experiment Fire Brigade did not have a procedure one was written by Richard Baines which they adopted Supply of gas BOC covered by Gas Regs This procedure was used for 1 installation 2003 was adopted again Inform grid the system is going to be connected or disconnected G83 Which standards were used IGEM Institution of gas engineers and managers and IET Institution of engineering and technology Who certified each component the overall system BAXI had the system CE marked in Germany Please provide a copy of the certificate of conformance 44 2 Was a risk analysis carried out YES e Please provide HAZOP information e Please provide information regarding to safety measures taken i e fire protection ventilation safety sensor etc The system was housed in a wooden shed it was treated more as a natural gas system would have been treated Fitted with leak detectors Nominal data Power out kWe 1 5kW Heat out kWth 3 0kw Fuel gas supply pressure bar 18 to 25 mbar Voltage V 230 Frequency Hz 50 Ambient temperature range C IP rating Dimensions m 100cm x 73 cm x 185 cm Weight kg 350
62. example of a soft barrier is a curtain made from polythene sheeting which would allow easy access to the area where the gas source is but would restrict the flow of gas to the surrounding areas 4 4 2 Avoidance of ignition sources If the formation of an explosive atmosphere cannot be prevented or the process operates with a flammable atmosphere the next level of protection is the avoidance of ignition sources in areas where a flammable atmosphere may occur The hazardous areas where explosive atmospheres could be formed have to be identified and classified according to the likelihood of an explosive atmosphere being present For situations where hydrogen and or other flammable gases or liquids may be present the following classifications should be used where appropriate e Zone 0 An area in which an explosive atmosphere is present continuously or for long periods Only category 1 equipment should be used in these areas e Zone 1 An area where an explosive atmosphere is likely to occur during normal operation Only category 1 or 2 equipment should be used in these areas e Zone 2 An area where an explosive atmosphere is not likely to occur during normal operation and if it does occur is likely to do so infrequently and will only last for a short period Only category 1 2 or 3 equipment should be used in these areas Guidance on identifying and classifying the hazardous areas is given in BS EN 60079 10 2003 and BS EN 1127 1 200
63. generally not recommended for use on hydrogen systems as it is difficult to achieve and maintain these in a leak free condition Where their use is considered essential such as on small bore pipe work they should be suitable for the duty and used in strict accordance with the manufacturer s instructions 23 INERIS D 4mm jet fire INERIS D 7mm jet fire INERIS D 10mm jet fire Sandia D 5 08mm jet fire UU LES jet fire Unignited jet 2 Chen amp Rodi Best fit for flame length HSL jetfire data Unignited jet 4 Chen amp Rodi UU LES unignited 4 A UU LES unignited 2 100 gt te i gt z c S HEH h E 1 v o c B 01 a Ta Jerr 2 Hydrogen lt TIH 4 Hydrogen 0 01 Visible Flame 0 001 Equivalent Diameter mm O 4OTN S852 OI NOS 0 1000 0 01 a 01 a T 1 O id 100 Figure 1 Nomogram for calculation of flame length of high momentum jet fire by a physical size of leak and pressure in a storage Particular attention should be given to the design and location joints in the system that may require regular maintenance or where mechanical joints will be frequently disturbed or made broken as the likelihood of leaks in these areas is increased The connection between the cylinder and the manifold is typical of these and should be checked with a suitable detection solution or suitable electronic gas detection device whenever the cylinder is cha
64. generate electromagnetic a view to meeting the Electromagnetic disturbance or the protection requirements set Compatibility performance of which is out in the Directive Regulations liable to be affected by such 2006 disturbance 2006 95 EC Electrical equipment The electrical equipment Low Voltage designed for use with a should be so designed and Directive voltage rating of between 50 manufactured as to ensure The Electrical and 1 000 V for alternating current and between 75 and protection against the hazards arising from the voltages at Equipment 1 500 V for direct current which the is used providing Safety that the equipment is used in Regulations applications for which it was 1994 8 made and is adequately maintained 2006 42 EC Machinery interchangeable The manufacturer or his Machinery equipment safety authorised representative Directive components lifting should also ensure that a risk accessories chains ropes assessment is carried out for Supply of and webbing removable the machinery which he Machinery mechanical transmission wishes to place on the market Safety devices partly completed For this purpose he should Regulations machinery determine which are the essential health and safety requirements applicable to his machinery and in respect of which he must take measures A list of useful codes and standards associated with the various parts of a fuel cell system is giv
65. ght of the facility protected No attempt should be made to extinguish fires involving hydrogen or other flammable gas cylinders unless they are in the open or in a well ventilated area free of combustibles and ignition sources Even if located in open or well ventilated areas extreme care should still be taken in attempting to extinguish the fire as this may create a mixture of air and escaping gas that if re ignited might explode Under no circumstances should firefighters attempt to remove a burning cylinder An appropriate exclusion zone should be set up and the burning cylinder s and any surrounding cylinders and combustibles should be kept cool by spraying them with water until the gas escape ceases and the fire extinguishes 4 6 3 Emergency plan A fire protection and emergency plan should be drawn up Personnel should receive specific training in dealing with emergencies involving hydrogen In particular they should know how hydrogen explosions and fires differ from those involving the more conventional gaseous fuels such as natural gas and LPG One example of a difference which is of particular relevance to hydrogen fires is that hydrogen flames are often invisible especially in bright sunlight increasing the likelihood of people fleeing an incident or emergency workers inadvertently straying into a flame 4 7 INTERCONNECTIVITY Manufacturers of equipment intended to be connected to networks should construct such equipment in a
66. guishers fire detection and alarms and staff training General fire precautions for the workplace are set out in the Workplace Directive 89 654 EEC which specifies the minimum requirements for health and safety in the workplace These requirements are implemented in England and Wales by the Regulatory Reform Fire Safety Order 2005 in Scotland by Fire Scotland Act 2005 and came into force on 1 October 2006 Under the new legislation fire certificates are no longer required and instead a risk based approach becomes the primary method to manage fire risk in the workplace Responsibility for compliance will rest with the Responsible Person In the workplace this is the employer and any other person who may have control of any part of the premises e g the occupier or owner The duty of the Responsible Person is to ensure that a suitable and sufficient fire risk assessment has been carried out for the site This amongst other things covers means of detecting and giving warning of a fire at the site measures to reduce the risk of fire and its spread means of escape from the site provision of fire fighting measures and the safety fire of fighters A recently published British Standard BS 9999 2008 gives recommendations and guidance on the design management and use of buildings to achieve reasonable standards of fire safety for all people in and around buildings 34 4 6 1 Overheating The fuel cell and any hydrogen generat
67. ially Explosive Atmospheres EPS Regulations 1996 Equipment electrical and non electrical and protective systems intended for use in potentially explosive atmospheres Hazardous area classification must be carried out to assess potential locations and likelihoods of an explosive atmosphere being present to ensure that any equipment cannot act as a source of ignition 97 23 EC Pressure Equipment Directive Pressure Equipment Regulations PER 1999 This directive applies to the design manufacture and conformity assessment of pressure equipment with a maximum allowable pressure greater than 0 5 bar above atmospheric pressure for the maximum minimum temperatures for which the equipment is designed for gases liquids and vapours The certification process by the Pressure Equipment Directive both certification by the manufacturer and by a notified body depends on a number of system parameters These parameters include the hazards posed by the pressurised gas liquid the characteristics and dimensions of the equipment and its intended use 2004 108 CE Electromagnetic Compatibility Directive Equipment or combinations thereof made commercially available as a single functional unit intended for the end user and liable to The manufacturer shall perform an electromagnetic compatibility assessment of the apparatus on the basis of the relevant phenomena with The
68. iderations cccccceeceeeeeeeeeeeeeeeeeeees 19 SYSTEM SPECIFIC AND SITE CONSIDERATIONG ccccceeeeeeeeeeees 21 Hydrogen GEMS FANON scoscese cerne earen ee ERA EER ARAE En aE EEE 21 Hydrogen containment and Piping cceeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeees 22 11 Lene ee ee ene a aa ae en ee eee ee eee eo 25 Explosion prevention and protection cccccceceecceeeeeeeeeeeeeeeeeeeeeeeeees 28 Hydrogen SAS eesse e etic ede cate a 33 Fire precautions erriei en E RE E 34 MterCOnnectiVIty va snssanscanapansdenspensGenapamsdenspeasGenapsesmenemenspenaniinnnddendeeedededenty 35 PERMITTING UTE esis tect tsecssnctaatasenaaacdeeteestetetenetoecioesteceatniataiadatadeeudaes 36 Outline approval checklist for commercial industrial installations 36 Outline approval checklist for domestic residential installations 38 APPENDIX 1 USEFUL CODES AND STANDARDG seeeeeeee 39 APPENDIX 2 CASE STUDIES 0 eee teeeeeeeeeeeeeeeeeeeeeeneeeeeeeneeeeeeeeeeees 43 APPENDIX 3 CE CERTIFICATION scciccsinistncncsecsncctsencnccssencseccceassscsssase 49 APPENDIX 4 HYDROGEN DETECTION TECHNIQUES 0000 52 APPENDIX 5 RISK ASSESSMENT METHODOLOGY 05 56 APPENDIX 6 ABBREVIATIONG eee eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeees 58 APPENDIX 7 REFERENCE ccccceeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeees 60 viii 1
69. ination of these Be aware of when the directive s come into force Identify if there are any Harmonised European Standards applicable to your product Ensure the components of the fuel cell system comply with the essential requirements of the directive s used Maintain technical documentation see section 2 required by the directive s Your technical documentation should support your compliance with the requirements of the directive It is essential to retain this documentation Provide in particular the necessary information such as instructions Prepare the Declaration of Conformity and the required supporting evidence The Declaration of Conformity along with the technical documentation should be available to competent authorities EU Members upon request Check that no other purely national requirements exist in the countries where the product will be sold These may include national standards labelling or packaging requirements Affix CE marking on your product and or its packaging and accompanying literature as stated in the directive In order to ensure the same quality for the CE marking and the manufacturer s mark it is important that they be affixed according to the same techniques In order to avoid confusion between any CE markings which might appear on certain components and the CE marking corresponding to the machinery it is important that the latter marking be affixed alongside the name of the person who has taken
70. ion and processing equipment must be designed and constructed in such a way as to avoid any risk of a fire being initiated by overheating Some types of fuel cell operate at temperatures in the range of 600 to 1000 C so even under normal conditions a high standard of thermal insulation will be required to prevent nearby equipment from overheating 4 6 2 Fire fighting Fires involving hydrogen should not be approached without appropriate flame detection equipment due to the low visibility of hydrogen flames Hydrogen fires should not be extinguished until the supply of hydrogen is shut off because of the danger of re ignition or explosion of an accumulation of unburnt hydrogen The recommended way of handling a hydrogen fire is to let it burn under control until the hydrogen flow can be stopped Small hydrogen fires can be extinguished by dry chemical extinguishers or with carbon dioxide nitrogen and steam Water in large quantities is the best way of extinguishing anything other than a small hydrogen fire and is required for spraying adjacent plant to keep it cool and preventing fire spread Water spray systems should be provided for hydrogen storage containers grouped piping and pumps where potential fire hazards exist The system s shall be arranged to deliver a uniform spray pattern over 100 per cent of the container surface pumps and adjacent piping Manual control stations shall be located outside the hazardous area but within effective si
71. ion of the forced airflow must be compatible with the expected movement of any hydrogen release as a result of buoyancy thermal effects etc Where differential pressure is used to prevent the ingress of hydrogen into adjoining compartments the pressurisation air should drawn from discharged to a safe place Also suitable fail safes should be in place to raise alarms cause shutdown in the case of any detected loss of ventilation or differential pressure The dilution airflow and the number and location of flammable atmosphere detectors should be appropriate in complex systems or congested areas An appropriate modelling technique should be used in these situations to ensure that pockets of flammable mixture will not accumulate and remain undetected In situations where other fuels such as methane LPG etc are present in addition to hydrogen the different densities and diffusivities need to be taken into account to ensure that the ventilation arrangements provided are adequate Ventilation is not recommended as a prevention measure for large leaks for example from the catastrophic failure of pipe as ventilation systems are unlikely to be able disperse large leaks quickly enough to prevent an explosive atmosphere accumulating If ventilation is used as a prevention measure then the reliability of the system has to be guaranteed and if the ventilation is only activated when a leak occurs then there must also be a reliable method e g gas detector
72. ipment to determine whether by its design or construction it is capable of being assembled and put into service safely The relevant reports and results shall be included in the technical file 50 The technical file must be made available to the competent authorities of the member states for at least 10 years following the date of manufacture of the equipment or in the case of series manufacture of the last unit produced The technical file does not have to be located in the territory of the Community nor does it have to be permanently available in material form However it must be capable of being assembled and made available within a period of time commensurate with its complexity by the person designated in the EC declaration of conformity The technical file does not have to include detailed plans or any other specific information as regards the sub assemblies used for the manufacture of the equipment unless knowledge of them is essential for verification of conformity with the essential health and safety requirements 3 EC declaration of conformity of the equipment This declaration relates exclusively to the equipment in the state in which it was placed on the market and excludes components that are added and or operations carried out subsequently by the final user The EC declaration of conformity must contain the following particulars e Business name and full address of the manufacturer and where appropriate his authorised represe
73. linders Compatibility of cylinder and cylinder valve with gas contents Test methods for selecting metallic materials resistant to hydrogen NFPA 55 Standard for the Storage Use and Handling of Compressed Gases and Cryogenic Fluids in Portable and Stationary Containers cylinders Equipment and Tanks National Fire Protection Association CGA C 10 Recommended procedures for changes of gas service of compressed gas cylinder Compressed Gas Association IGC Doc 100 03 E Hydrogen cylinders and transport vessels European Industrial Gases Association CGA PS 20 CGA Position Statement on the Direct Burial of Gaseous Hydrogen Storage Tanks Compressed Gas Association CGA PS 21 Position Statement on Adjacent Storage of Compressed Hydrogen And Other Flammable Gases Compressed Gas Association CGA Doc 02 50 Hydrogen Storage in Metal Hydrides Compressed Gas Association General hydrogen safety Biennial Report on Hydrogen Safety HYSAFE Network of Excellence Guidance for using hydrogen in confined spaces InsHYde project internal project of the HYSAFE Network of Excellence ISO TR 15916 2004 Basic Considerations for the Safety of Hydrogen Systems Dangerous Substances and Explosive Atmospheres Regulations DSEAR 2002 ANSI AIAA G 095 2004 Guide to Safety of Hydrogen and Hydrogen System American National Standards Institute American Institute of Aeronautics and Astranautics
74. ment is installed and maintained by a competent person Step 5 Inform the local fire brigade of the location and type of installation and especially for the more complex installations give the opportunity to visit and familiarise themselves with the installation Of particular interest would be the location and quantity of any hydrogen stored on the site For domestic installations it would also be prudent to inform the property insurers of the installation 10 11 12 CONTENTS INTRODUCTION AND SCOPE ccccceeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeees 1 How the document was produced cceceeeeeeeeeeeeeeeeeeeeeeeaeeeeneeeretees 1 How to use the DOGUIM GIN sisiccscisdcnidaseindannducndueisbiniseilesanavewevanaiarievavenmavicawns 1 SCOPE aae e E E E EE E E E S 2 BACKGROUND issis ssion apa nr rr SS ec EAEAN EEEa 3 Fu l ey SES eirin soi aE EE EE TEENE 3 Hazards associated with fuel cell installation and operation 4 Properties and characteristics of hydrogen eee eee eee e eee eeeeeeeeees 5 GENERAL AND HIGHER LEVEL REQUIREMENTSG csssessseeeeeeeeeees 9 Design and manufacturing requireMents ccceeeeeeeeeeeeeeeeeeeeeeeeeeeeees 9 Installation requirements ssencnciclcseecsishucncsdetiamducnivansanincsacusledsniebiawsunincaterensds 14 Regulatory approval considerations cece e cece eee eeeeeeeeeeeeeeeeeeeeeeeeeeeeees 16 Operational maintenance cons
75. mum total ventilation area of 0 003 m m of room volume was set for the inlet and outlet openings Discharge from outlet openings shall be directed or conducted to a safe location Ventilation openings shall be designed so that they will not become obstructed during normal operation by dust snow or vegetation in accordance with the expected application In open air situations natural ventilation will often be sufficient to ensure dispersal of any explosive gas atmosphere which arises in the area For outdoor areas the evaluation of ventilation should normally be based on an assumed minimum wind speed of 0 5 m s which will be present virtually continuously EN 60079 10 2003 The effect of wind should be borne in mind when deciding vent orientation Depending on the position of the vents wind may impede or enhance the ventilation efficiency 29 If it can be verified natural ventilation should be permitted to provide all required ventilation and makeup air If mechanical ventilation is required the ventilation system shall be interlocked to the hydrogen process equipment to prevent process equipment from working in the absence of ventilation and therefore shut it down upon loss of ventilation It shall also be equipped with an audible and visual alarm in order to give a warning in case of failure The ventilation unit shall be constructed and installed in such a way as to preclude the presence of mechanical and electrical sparking The f
76. nd appropriate components within a hydrogen system however will significantly reduce the likelihood of this occurring if fitted by a competent person For high pressure storage systems hydrogen would leak nearly three times faster than natural gas and over five times faster than propane However the low energy density of hydrogen means that it produces substantially lower energy leakage rates 2 3 1 2 Extremely high diffusivity Hydrogen is very much lighter than air and is also very diffusive Thus unlike heavier gaseous fuels if a hydrogen leak occurs in an open or well ventilated area its diffusivity and buoyancy will help to reduce the likelihood of a flammable mixture forming in the vicinity of the leak 6 However as with other gases when leaks occur within poorly ventilated or enclosed areas the concentration may rapidly reach dangerous levels Due to its lightness hydrogen will concentrate in elevated regions of an enclosed space whereas other gases dependent upon their relative mass will concentrate at ground level LPG or at elevation CNG If unprotected electrical equipment or other sources of ignition are present the risk from explosion could be considerable As hydrogen diffuses more rapidly through air and through solid materials compared to other fuel gases such as methane or propane it will usually disperse more rapidly if released although buoyancy effects are less significant for high momentum releases from high pre
77. nged Pipe routing should reflect consideration of factors such as risk from impact damage formation of flammable mixtures in poorly ventilated areas heat sources etc Consequently where pipe work passes through enclosed ducts cavity walls etc there should be no mechanical joints Piping should preferably be routed above ground if underground pipe work is unavoidable it should be adequately protected against corrosion The position and route of underground piping should be recorded in the technical documentation to facilitate safe maintenance inspection or repair Underground hydrogen pipelines should not be located beneath electrical power lines Pipe work should be cleaned before being place into service using a suitable procedure for the type of containment which provides a level of cleanliness required by the application Systems should be suitably purged using an inert gas i e nitrogen to prevent the existence of a hydrogen air mixture Purging can be by sweep purging evacuation or repeated pressurisation 24 and venting cycles using appropriately engineering and sited vent and purge connections Also consideration should be given to the asphyxiation hazards of using inert gases 4 3 SITING Requirements applicable to the siting of stationary fuel cell installations fuelled by hydrogen and of their attendant storage and hydrogen generation systems the installation will vary according to whether the installation is lo
78. nt of flammable gases BS EN 60079 29 1 2007 Explosive atmospheres Gas detectors Performance requirements of detectors for flammable gases BS EN 60079 29 2 2007 Explosive atmospheres Gas detectors Selection installation use and maintenance of detectors for flammable gases and oxygen ISO DIS 26142 Hydrogen Detection EN 50073 1999 Guide for selection installation use and maintenance of apparatus for the detection and measurement of combustible gases or oxygen BS EN 62282 3 3 2008 Fuel cell technologies Part 3 3 Stationary fuel cell power systems Installation ISO TR 15916 2004 Basic Considerations for the Safety of Hydrogen Systems ANSI A1AA G 095 2004 Guide to Safety of Hydrogen and Hydrogen System American National Standards Institute American Institute of Aeronautics and Astranautics Explosion venting EN 14994 2007 Gas Explosion Venting Protective Systems NFPA 68 Standard on explosion protection by deflagration venting 2007 edition National Fire Protection Association Electrolysers BS ISO 22734 1 2008 Hydrogen generators using water electrolysis process Industrial and commercial applications ISO CD 22734 2 Hydrogen generators using water electrolysis process Part 2 Residential applications BS ISO 16110 1 2007 Hydrogen generators using fuel processing technologies Reformers Safety ISO DIS 16110 1 2007 Hydrogen generators
79. ntative e Name and address of the person authorised to compile the technical file who must be established in the Community e Description and identification of the equipment including generic denomination function model type serial number and commercial name e A sentence expressly declaring that the equipment fulfils all the relevant provisions of the relevant directive s and where appropriate a similar sentence declaring the conformity with other directives and or relevant provisions with which the equipment complies These references must be those of the texts published in the Official Journal of the European Union e Where appropriate the name address and identification number of the notified body which carried out the EC type examination and the number of the EC type examination certificate e Where appropriate the name address and identification number of the notified body which approved the full quality assurance system e Where appropriate a reference to the harmonised standards used e Where appropriate the reference to other technical standards and specifications used e The place and date of the declaration e The identity and signature of the person empowered to draw up the declaration on behalf of the manufacturer or his authorised representative 51 9 APPENDIX 4 HYDROGEN DETECTION TECHNIQUES There are several types of hydrogen sensors depending on its intended use The electrochemical catalytic an
80. ntional fuels like natural gas For small scale stationary applications the usual method of delivery from production facilities to site is by single transportable cylinders or manifolded packs of cylinders An option for the future is via the existing natural gas transmission system Work is currently in progress to explore the feasibility of using the existing system to transport mixtures of natural gas and hydrogen with the hydrogen being separated out at the point of use Methods of on site production include reforming of natural gas the gas being supplied by the existing natural gas distribution network and the electrolysis of water Production units being developed for domestic applications potentially have the capability to generate enough hydrogen to supply a fuel cell to provide electricity and heating for the home and re fuel a hydrogen powered car The widespread adoption of on site production would reduce the need for large scale hydrogen production facilities and the associated distribution and storage infrastructure 4 1 2 Standards and guidance General guidance on the safety of hydrogen systems can be found in the International Standard Organisation s Technical Report ISO TR 15916 2004 The International Standards Organisation ISO has published or is developing standards specifically dealing with hydrogen production systems ISO 161 10 1 2007 covers the safety of stationary hydrogen generators intended for indoor or o
81. o apply to systems up to 100 kWel which will serve small communities or groups of households The document is not a standard but is a compendium of useful information for a variety of users with a role in installing these systems including design engineers manufacturers architects installers operators maintenance workers and regulators This report and the work it describes were funded by the Health and Safety Executive HSE Its contents including any opinions and or conclusions expressed are those of the authors alone and do not necessarily reflect HSE policy HSE Books Crown copyright 2009 First published 2009 All rights reserved No part of this publication may be reproduced stored in a retrieval system or transmitted in any form or by any means electronic mechanical photocopying recording or otherwise without the prior written permission of the copyright owner Applications for reproduction should be made in writing to Licensing Division Her Majesty s Stationery Office St Clements House 2 16 Colegate Norwich NR3 1BQ or by e mail to hmsolicensing cabinet office x gsi gov uk ACKNOWLEDGEMENTS The contribution of the HYPER project partners listed below to the HPYER Installation Permitting Guidance which was used as the basis of this UK installation permitting guidance is gratefully acknowledged Commissariat a l Energie Atomique Ecofys Netherlands BV Exergy Fuel Cells s r l Forschungszentrum Ka
82. ocuments containing the product design and security measures that make it safe Prototype and demonstration units are not required to have CE marking A number of Agreement of Mutual Recognition of Conformity Assessment between the EC and third countries USA Canada Australia Japan New Zealand and Israel allows industries based in those countries to use local certification organisations accredited for the specific directive To assist fuel cell components manufacturers relevant directives and the UK regulations that implement the requirements of the directives are listed in Table 2 A checklist that can be used when seeking EC certification together with further details on the CE mark the Technical Construction File and the EC Declaration of Conformity can be found in Appendix 3 Table 2 Relevant directives requiring compulsory CE marking Directive Applicable to Comments 90 396 EEC Appliances burning gaseous Strictly only applicable to fuel Gas Appliance fuels used for cooking cells where the primary Directive heating hot water function is heating However production refrigeration some principles on general The Gas lighting or washing and health and safety Appliances having where applicable a considerations may still be Safety normal water temperature useful Regulations not exceeding 105 C 1995 94 9 EC ATEX Equipment Directive Equipment and protective Systems for Use in Potent
83. omplexity of the installation Areas to be considered when identifying the hazards may will include Site location site evaluation hydrogen storage location security choice of materials access deliberate attack and vandalism impact ventilation fire protection location of safety sensors connection to grid A suitable emergency plan should be drawn up in the event of a leak or fire Step 2 Decide who may be harmed and how For each hazard identified in Step 1 assess who might be harmed and how Step 3 Evaluate the risks and decide what to do about them Consideration should be given to removing the hazard and if that is not practical how the hazard can be reduced or controlled Step 4 Record and implement the findings The risk assessment should show that all significant hazards have been recorded and addressed and how the hazards will be eliminated or if they cannot be eliminated how their effects will be minimised Employees must be informed about the outcome of the risk assessment The precautions taken should be reasonable and if there is a residual risk it should be low Step 5 Review the Risk Assessment and update if and when necessary Records of the installation maintenance checks and servicing should be kept Any changes to the installation work activities process or incidents should be recorded and the risk assessment reviewed and if necessary additional safety measures implemented A risk assessment can be
84. on is the preferred method due to its intrinsic reliability If forced ventilation is used then the reliability of the system has to be considered Appliances which are not fitted with devices such as flues to avoid a dangerous accumulation of unburned gas or combustion products in indoor spaces and rooms should be used only in areas where there is sufficient ventilation to avoid accumulation to dangerous levels 3 2 3 Pressure systems Suitable means must be provided for testing and venting pressure equipment The risk assessment for the installation should cover the pressurising and venting operations Adequate means must also be provided to permit cleaning inspection and maintenance in a safe manner of all pressure systems 3 2 4 Materials selection for installation Materials used for the installation of hydrogen and fuel cell equipment must be suitable for such application during the scheduled lifetime unless replacement is foreseen Where necessary adequate allowance or protection against corrosion or other chemical attack must be provided taking due account of the intended and reasonably foreseeable use Hydrogen gas dissolved in liquids will permeate into adjoining vessel materials At elevated temperatures and pressures hydrogen attacks mild steels severely causing decarburisation and embrittlement It is therefore vital that if hydrogen is stored or handled under pressure compatible materials e g special alloy steels are used f
85. on regime should be sufficient to ensure that the hydrogen concentration is normally maintained below 10 of the LEL 0 4 v v for hydrogen with only occasional temporary increases to 25 of the LEL Some basic equations for a calculating degrees of ventilation are described in BS EN 60079 10 2003 Two main types of ventilation are recognised a Passive or natural ventilation the flow of air or gases is created by the difference in the pressures or gas densities between the outside and inside of a room or enclosed space b Active or forced mechanical ventilation the flow of air or gas is created by artificial means such as a fan blower or other mechanical means that will push or induce an air flow through the system The artificial ventilation of an area may be either general or local Natural ventilation can be provided by permanent openings The location of the openings shall be designed to provide air movement across the room or enclosed space to prevent the unwanted quantities of hydrogen air mixtures Inlet openings for fresh air intakes should be located near the floor in exterior walls and only in such a way so that they do not reintroduce air previously evacuated from the process area Outlet openings should be located at the high point of the room in exterior walls or roof Inlet and outlet openings shall each have a minimum total set area of the room volume In the ANSI AIAA Guide for Hydrogen and Hydrogen System a mini
86. ons such as porches covered ways and conservatories However it is good practice to have exemption confirmed by the appropriate authority prior to construction The Building Regulations 2006 as amended lay down the requirements for England and Wales Approved Documents have been published for the purpose of providing practical guidance on meeting the requirements of the Regulations For fuel cell installations the most relevant approved documents are Part A Structure Part B Fire Safety Part F Ventilation Part J Combustion Appliances and Fuel Storage Part L Conservation of Fuel and Power and Part P Electical Safety Scotland has its own building regulations the Building Scotland Regulations 2004 which are broadly in line with the English and Welsh regulations Guidance on achieving the requirements of the Regulations are given in a series of Technical Handbooks 3 3 2 Regulations In the UK the principal regulations covering hydrogen facilities arise from the national legislation passed to implement the ATEX Directives and the Pressure Equipment Directive Their requirements are not specific to hydrogen and would equally apply to any fuel that is capable of generating a flammable atmosphere for example natural gas or LPG or equipment that contains a fuel under pressure For some components of the installation for example if the hydrogen is produced in situ by the reformation of natural gas the requirements of the Gas A
87. or pipe work vessels etc 3 2 5 Mechanical and thermal hazards Equipment must be designed and constructed to minimise the risk of injuries from moving parts and hot surfaces If there are moving parts appropriate guarding should be provided to prevent accidental contact or ejection of failed components Hot components need to be insulated or a means provided of preventing accidental contact 15 3 2 6 Slipping tripping or falling hazards Access to the equipment should be such that there are no slipping tripping or falling hazards for personnel delivering supplies e g gas cylinders undertaking maintenance or carrying out repairs to the installation Rooms or enclosures containing equipment should be fitted with measures to prevent a person from being accidentally trapped within it or if that is impossible with a means of summoning help 3 2 7 Lightning protection Outdoor installations may also need protection against lightning strikes This can be achieved by fitting a system for conducting the resultant electrical charge to earth and also ensuring all equipment is electrically bonded and earthed 3 2 8 Gas venting In electrolyser fed systems venting facilities for hydrogen and oxygen should be separate and isolated from each other 3 2 9 Manual handling Equipment or each component part thereof must be capable of being handled and transported safely be packaged or designed so that it can be stored safely and
88. orced ventilation of an area may be either general or local and for both of these differing degrees of air movement and replacement can be appropriate Although forced ventilation is mainly applied inside a room or enclosed space it can also be applied to situations in the open air to compensate for restricted or impeded natural ventilation due to obstacles As in the case of natural ventilation the dilution air used to artificially ventilate the area should enter at low level and be taken from a safe place The ventilation outflow should be located at the highest point and discharge to a safe place outdoors Furthermore the mechanical means used to ventilate the enclosure should be suitable and in particular the electrical motor s should not be located in the potentially contaminated exhaust air stream Suitable arrangements should be in place to detect when the ventilation system is failing to provide adequate ventilation This may be based on the measurement of flow or pressure This should raise an alarm and safely isolate the electricity supply outside the enclosure and the hydrogen supply outside the building with a normally closed fail safe valve The fuel cell system should shut down safely upon loss of adequate ventilation The cooling air supply fan or compressor present in many fuel cell modules may sometimes be suitable to provide effective ventilation Where this approach is used the air must be drawn from a safe place and the direct
89. ources to be monitored valves flanges connections bellows etc and provide valid justification for sources not monitored At hydrogen connections that are routinely separated for example hydrogen refuelling ports Locations where hydrogen could accumulate In building air intake ducts if hydrogen could be carried into the building In building exhaust ducts if hydrogen could be released outside the building The following points should also be considered An understanding of how a gas leak disperses is required to choose the correct location to install the detection device s Hydrogen being less dense than air will rise when released and disperse rapidly When thinking of the location of hydrogen sensors detectors take the response time into consideration The LEL used shall be the LEL of the gas or gas mixtures When positioning detectors local airflow also needs to be considered Intuitively hydrogen detectors should be placed above a potential leak source however airflow may carry the hydrogen downstream away from the detector and before reaching the ceiling In that case detection may be delayed or even prevented Temperature can also have an effect on the dispersion of a gas As hot air rises a layer of lower density air forms at the ceiling creating a thermal barrier which may slow the diffusion of leaking hydrogen enough to delay detection at the sensor A combustible gas detector that meets the above re
90. ovided in Appendix 7 1 3 SCOPE The IPG provides a structured analysis of known documents relevant for permitting hydrogen and fuel cell systems in the UK and documents best practice for the installation of different generic types of hydrogen and fuel cell systems It also provides guidance on issues not properly dealt with in existing documents and therefore provides the basis for harmonised permitting guidance The IPG takes account of the already established permitting requirements for natural gas appliances The IPG applies to stationary systems fuelled by hydrogen incorporating fuel cell devices with net electrical output of up to 10kWel small according to IEC 62282 3 3 2007 and with total power outputs of the order of 50kW combined heat electrical suitable for small back up power supplies residential heating combined heat power CHP and small storage systems Many of the guidelines appropriate for these small systems will also apply to systems up to 100 kWel which will serve small communities or groups of households 2 BACKGROUND 2 1 FUEL CELL SYSTEMS 2 1 1 Types of fuel cell A fuel cell is an electrochemical device that combines hydrogen and oxygen to produce electricity heat and water The hydrogen may be produced as a by product of a chemical process extracted from any hydrocarbon fuel such as natural gas gasoline diesel or methanol via a fuel reformer or by electrolysis of water The oxygen is usually obtaine
91. perating instructions At elevated temperatures and pressures hydrogen attacks mild steels severely causing decarburisation and embrittlement This is a serious concern in any situation involving storage or transfer of hydrogen gas under pressure Proper material selection e g special alloy steels and technology is required to prevent embrittlement 3 1 9 General health and safety requirements General health and safety requirements should be addressed with respect to e Materials and products External temperatures Errors of fitting Extreme temperatures Noise Vibrations External radiation Emissions of hazardous materials and substances Risk of being trapped in a machine Risk of slipping tripping or falling Lightning 3 1 10 Control system requirements For an appliance equipped with safety and controlling devices the functioning of the safety devices must not be overruled by the controlling devices see the BS EN series of standards for control device requirements All parts of appliances that are set or adjusted at the stage of manufacture and which should not be manipulated by the user or the installer must be appropriately protected Levers and other controlling and setting devices must be clearly marked and give appropriate instructions to prevent any error in handling Their design must preclude accidental manipulation The surface temperature of knobs and levers of appliances mu
92. ppliances Directive may also be applicable ATEX is the name commonly given to the framework for controlling explosive atmospheres arising from gases vapours mists or dusts and the standards of equipment and protective systems used in them It is based on the requirements of two European Directives The first is Directive 94 9 EC also known as ATEX 95 or ATEX Equipment Directive on the approximation of the laws of member states concerning equipment and protective systems intended for use in potentially explosive atmospheres The EPS Regulations implements the requirements of the Directive in the UK Any equipment electrical or non electrical or protective system designed manufactured or sold for use in potentially explosive situations has to comply with the essential health and safety requirements EHSR set out in the Regulations The second is Directive 99 92 EC also known as ATEX 137 or the ATEX Workplace Directive on the minimum requirements for improving the health and safety protection of workers potentially at risk from explosive atmospheres DSEAR implements the requirements of the ATEX Workplace Directive in the UK The key requirement of DSEAR is that risks from dangerous substances e g flammable gases are assessed and controlled As the ATEX Directives and thus the DSEAR and the EPS Regulations only apply to the workplace hydrogen fuel cells installed in domestic premises are outside their scope Nonetheless the haz
93. pplications to increase energy storage density As a cryogenic liquid hydrogen is stored as a liquid below 250 C therefore consideration should be given to cold burns condensation of oxygen enriched atmospheres and the way in which a liquid spill may develop into a flammable cloud It should be appreciated that the vapour produced by a liquid spill will not initially be buoyant due to its low temperature Complex hydrides are also used as a hydrogen storage medium generally based on sodium aluminium hydrides or similar materials These materials are flammable solids and can react violently with water to produce hydrogen and a corrosive aqueous solution Hydride storage systems can be suitably designed to avoid these hazards 2 3 PROPERTIES AND CHARACTERISTICS OF HYDROGEN Hydrogen is a colourless odourless gas that is lighter than air The use of odorants to detect leaks is being investigated however all the odorant chemicals so far considered have been rejected due to concerns regarding their potential to poison the fuel cell membrane catalysts Furthermore they may have limited effectiveness for small leaks as the odorant molecules will inevitably be much larger than the hydrogen molecules Hydrogen has many characteristics which are significantly different from conventional fuels and which it is important to take into account when designing and installing a fuel cell system A comparison of the characteristics of hy
94. quirements should be provided for all indoor or separately controlled gas compressors When hydrogen is stored as a cryogenic liquid and leaks its density is initially greater than air causing it to settle to the ground before heating up becoming lighter than air and eventually rising 53 8 Dilution of hydrogen increases the further the detector is from the site of the leak As a result the actual hydrogen concentration can be higher than the concentration indicated by the detection device when the device is located far from the leak site For this reason detectors should be placed close to a potential leak site and should be sufficient in number to cover the installation 9 It is recommended that a hydrogen sensor be placed at the most elevated point in an enclosed space 10 Ifa forced ventilation system is installed then a sensor should be placed where the ventilation is applied Alarm levels Alarms associated with hydrogen detection should be set as low a level as possible lt 10 LEL without causing false alarms and should provide time to respond in a appropriate manner Where the detection shutdown system is a key part of the risk management system it should conform to an appropriate standard e g EN 50073 1999 Hydrogen system operators should have a portable hydrogen detector available for their use Once an alarm is triggered shutdown of the system should occur as quickly as possible to minimise the hydrogen inventory
95. r parts of the plant The distinction between the two types is important as in some applications it may only be necessary to achieve flame isolation The systems can be either be an active type which requires a means of detecting the explosion and initiating an action to implement the isolation or passive and requires no additional equipment to function Examples of an active system are a quick acting valve a complete isolation system or an extinguishing barrier The later system provides partial isolation by injecting a curtain of suppressant into the pipe or duct to quench the explosion An example of a passive partial isolation system is a flame arrester This device contains an arresting element comprising a matrix of small apertures or convoluted gas pathways with dimensions large enough to allow gas flow with minimal pressure drop but small enough to quench and prevent the passage of flame through the element A standard prEN 15089 is under development that will specify the general requirements for explosion isolation systems excluding flame arresters and the methods for evaluating the effectiveness of different systems BS EN 12874 2001 specifies the performance requirements test methods and limits for use of flame arresters 4 4 3 4 Containment systems An alternative mitigation technique to those that aim to reduce the explosion pressure is to use equipment for example process vessels strong enough to contain the explosion Equipmen
96. ralhy net ISO TR 15916 2004 Basic considerations for the safety of hydrogen systems 61 34 35 36 Sh 38 39 40 41 42 43 44 45 46 47 48 49 50 51 ISO 16110 1 2007 Hydrogen generators using fuel processing technologies Part 1 Safety ISO DIS 16110 2 Hydrogen generators using fuel processing technologies Part 2 Test methods for the performance efficiency standard under development ISO DIS 22734 1 Hydrogen generators using water electrolysis Part 1 Industrial and commercial applications ISO CD 22734 2 Hydrogen generators using water electrolysis Part 1 Residential applications standard under development due to be published 2010 ISO 14687 1999 Hydrogen fuel Product specification IGC Doc 15 06 E Gaseous hydrogen stations European Industrial Gases Association EIGA DOC 06 02 E Safety in storage handling and distribution of liquid hydrogen European Industrial Gases Association EIGA An installation guide for hydrogen fuel cells and associated equipment Draft 12 UK Hydrogen Association NFPA 55 Standard for the storage use and handling of compressed gases and cryogenic fluids in portable and stationary containers cylinders and tanks 2005 Edition National Fire Protection Association EN 1127 1 2007 Explosive atmospheres Explosion prevention and protection Part 1 Basic concepts and methodology EN 60079 1
97. responsibility for it namely the manufacturer or his authorised representative 2 Technical file The technical file must demonstrate that the equipment complies with the requirements of the relevant directive s It must cover the design manufacture and operation of the equipment to the extent necessary for assessment The technical file must be compiled in one or more official Community languages except for the instructions for the machinery for which the special provisions apply and are described in the relevant directive s The technical file shall comprise a construction file including A general description of the equipment 49 e The overall drawing of the equipment and drawings of the control circuits as well as the pertinent descriptions and explanations necessary for understanding the operation of the equipment e Descriptions and explanations necessary for the understanding of said drawings and schemes and the operation of the electrical equipment e Full detailed drawings accompanied by any calculation notes test results certificates etc required to check the conformity of the equipment with the essential health and safety requirements The documentation on risk assessment demonstrating the procedure followed This documentation shall include e A list of the essential health and safety requirements which apply to the equipment e The description of the protective measures implemented to eliminate identified
98. rlsruhe GmbH Institut National de l Environnement Industriel et des Risques National Centre for Scientific Research Demokritos PlugPower Holland BV Pro Science Gesselschaft fur wissenschaftliche und technische Dienstleistungen mbH Russian Research Centre Kurchatov Institute Sandia National Laboratories University of Manchester University of Pisa University of Ulster Vaillant GmbH EXECUTIVE SUMMARY Objectives The HYPER project started on 1 November 2006 and ended in February 2009 The work programme of the HYPER project was structured around the development of an installation permitting guide IPG which includes An assessment of current knowledge on installation requirements of small stationary hydrogen and fuel cell systems s Detailed case studies of representative installations b Modelling and experimental risk evaluation studies to investigate fire and explosion phenomena The IPG was developed in response to the growing need for guidance to facilitate small hydrogen and fuel cell stationary installations in Europe This report is a revised version of the IPG intended for the UK market reference being made to UK national regulations and standards as opposed to European as appropriate This document is not a standard but is a compendium of useful information for a variety of users with a role in installing these systems including Design engineers e Manufacturers Architects Installers Operators Main
99. s of detecting the leak Guidance on the selection and location of gas detectors is given in Appendix 4 There is a higher risk of an explosive atmosphere being present in equipment during commissioning when items of equipment will initially contain air before assembly or during maintenance when equipment is opened up for inspection repair allowing air ingress For these 30 operations inerting can be employed to prevent an explosive atmosphere forming Inerting is a technique by which the equipment is purged with an inert gas such as nitrogen or carbon dioxide until the oxygen concentration falls below the level required for flame propagation to occur This is called the limiting oxygen concentration LOC The LOC depends on the inert gas being used inerts with higher heat capacities being more efficient and giving higher values of LOC for a given flammable gas For inerting with nitrogen the LOC for hydrogen is 5 v v while for inerting with carbon dioxide it is 6 v v Guidance on the application of the inerting technique can be found in the ISO published document PD CEN TR 15282 2006 Even if the formation of an explosive atmosphere cannot be prevented then at a minimum measures should be implemented to limit the extent of the explosive atmosphere Such measures could include ventilation use of gas tight seals on doors pipe entry points etc to prevent gas migration between rooms and compartments and the use of a soft barrier An
100. ssure hydrogen systems When harnessed through intelligent equipment design and layout this buoyancy and hydrogen s rapid dispersion rate can become a significant safety asset 2 3 1 3 High buoyancy The buoyancy of hydrogen can also be used to manage the risk normally associated with fuel handling by segregating the hydrogen from foreseeable sources of ignition using internal partitions and bulkheads and differential pressurisation This can also be done by locating all potential sources of ignition well below the level of the equipment from which hydrogen may leak and accumulate and ensuring adequate ventilation and safe discharge of the exhaust 2 3 2 Propensity to cause embrittlement Hydrogen can cause embrittlement of high strength steels titanium alloys and aluminium alloys with cracking and catastrophic failure of the metals at stress below the yield stress This is most commonly related to the carbon content of metallic alloys Pure unalloyed aluminium however is highly resistant to embrittlement The industry standard for components in hydrogen service is grade 316 stainless steel Cupro nickel is also suitable for hydrogen service and copper can be used for low pressure applications 2 3 3 Propensity to ignite 2 3 3 1 Wide flammability range Hydrogen readily forms an explosive mixture with air The range of hydrogen air mixtures that will explode is wide Mixtures containing from as little as 4 v v hydrogen which is the lower
101. st not present a danger to the user Other areas that need to be addressed in the design of the control system are Safety and reliability of control systems Control devices Starting Stopping Selection of control or operating modes Failure of the power supply e aa qgaadi o Equipment Information warnings markings and instructions The EU Equipment Directives and the UK implementing regulations contain requirements relating to e Information and information devices e Warning devices Warning of residual risks Marking of equipment Instructions 3 2 INSTALLATION REQUIREMENTS Appliances must be correctly installed and regularly serviced in accordance with the manufacturer s instructions 3 2 1 Installation location Where practical particularly for industrial applications the fuel cell should be located outdoors Fuel cells for residential applications should be designed installed operated and maintained to be safe in typical indoor locations For non residential indoor installations the fuel cell should be located in a well ventilated area in which combustible materials are minimised In designing the installation consideration should be given as to whether it is necessary to separate the rooms or spaces that enclose the fuel cell installation from other building areas by fire barriers Use of appropriate protective devices for openings i e doors shutters windows service en
102. t intended to withstand an internal explosion are classed as one of two types Explosion pressure resistant equipment is designed to withstand the expected internal explosion pressure without becoming permanently deformed Explosion pressure shock resistant equipment is designed to withstand the expected internal explosion pressure without rupturing but allowing for some permanent deformation EN 14460 2006 specifies the requirements of the two classes of equipment 4 4 3 5 Blast walls Equipment and plant vulnerable to blast damage can be protected by blast walls These are strong walls positioned between the item to be protected and the expected source of blast that will deflect the blast wave and thus reduce the intensity of explosion pressure experienced They can also provide protection from missiles generated by the explosion The possible beneficial and detrimental effects of blast walls on the dispersion of leaking gas need to be taken into account in the assessment of the explosion hazards Depending on the circumstances for example wind direction and site layout blast walls may limit the spread of an explosive gas air cloud On the other hand walls may extend the time an explosive cloud is present and thus the likelihood of an ignition by inhibiting the dispersion of the gas by the wind These effects are more likely to be important for gases other than hydrogen as due to its low density there will be a significant upward dispersal due
103. te precautions such as containment and ventilation should be taken to prevent spillages and the accumulation of hazardous methanol air mixtures whenever it is used Compared to the hazards associated with more conventional equivalents to fuel cells e g natural gas boilers and batteries some different hazards have to be taken into account including not only the fuel cell but also the means of fuel production storage and transportation 2 2 2 Fire and explosion hazards The estimation of hazards and hazard levels is essential to the consideration of accidental consequences e g overpressures thermal radiation the throw of debris or missiles and the damage level or the vulnerability of the receiving objects In chemical fires explosions that are usually exothermal oxidation reactions a great proportion of the combustion energy is carried by the developing blast wave uniformly distributed in all directions Many flammable gases are widely in use today such as methane propane etc Without appropriate measures being taken a gas release and subsequent fire and explosion can occur Hydrogen has some significantly different properties from these more commonly used gases which need to be fully appreciated to achieve comparable levels of safety Hydrogen for use in fuel cells may be stored in a number of ways As a compressed gas normally in conventional gas cylinders at a pressure of 200bar but this pressure may be increased in specialist a
104. tenance workers Regulators The document is organised as follows Introduction and Scope Chapter 1 Introduction to fuel cell systems and their associated hazards Chapter 2 General and Higher Level Requirements Chapter 3 System Specific and Siting Considerations Chapter 4 Permitting Route Chapter 5 Appendices The IPG applies to stationary systems fuelled by hydrogen incorporating fuel cell devices with net electrical output of up to 10kWel and with total power outputs of the order of 50kW combined heat electrical suitable for small back up power supplies residential heating combined heat power CHP and small storage systems Many of the guidelines appropriate for these small systems will also apply to systems up to 100 kWel which will serve small communities or groups of households Recommendations The complexity of the permitting route required for a particular installation should be proportionate to the scale intended use and location of the installation Residential installations are likely to require a simpler permitting route than a commercial or industrial installation It is recommended however that any permitting route should comprise at least the following five steps vi Step 1 Undertake a risk assessment to identify the hazards and the measures to be implemented to eliminate or mitigate their effects The principal hazards will be fire and explosion ones but other hazards e g electrical
105. tents including any opinions and or conclusions expressed are those of the authors alone and do not necessarily reflect HSE policy www hse gov uk
106. the maintenance records with experience in the installation Information on maintenance protocol should be found in the user manual supplied by the manufacturer 54 References l 2 Biennial Report on Hydrogen Safety Chapter 5 www hysafe org BRHS ISO TR 15916 2004 Basic considerations for the safety of hydrogen systems HYSAFE Deliverable D5 4 Report on sensor evaluation www hysafe org deliverable InsHyde Project Deliverable D113 Initial guidance for using hydrogen in confined spaces Results from InsHyde www hysafe org inshyde IEC 62282 3 3 2007 Fuel cell technologies Part 3 3 Stationary fuel cell power systems Installation NASA NSS 1740 16 Safety Standard for Hydrogen and Hydrogen Systems National Aeronautics and Space Administration NASA EN 50073 1999 Guide for selection installation use and maintenance of apparatus for the detection and measurement of combustible gases or oxygen 55 10 APPENDIX 5 RISK ASSESSMENT METHODOLOGY An example of the steps necessary to complete a risk assessment is given below This is not the only way to perform a risk assessment but this method helps to assess health and safety risks in a straightforward manner The law does not expected all risks to be eliminated but protection of people as far as reasonably practicable is required Step 1 Identify the hazards The types of hazards identified and the methods used will vary according to the c
107. tion to objects near the flame thus reducing the risks of secondary ignition and burns However such effects have not been fully quantified and further work is needed in this area 2 3 4 2 Rapid burning rate The maximum burning velocity of a hydrogen air mixture is about eight times greater than those for natural gas and propane air mixtures The high burning velocity of hydrogen makes it difficult to confine or arrest hydrogen flames and explosions particularly in closed environments In its favour however this rapid rate of deflagration means that hydrogen fires transfer less heat to the surroundings than other gaseous fuel fires thereby reducing the risk of creating secondary fires in neighbouring materials Another downside of a higher burning velocity of hydrogen is that for a given scenario hydrogen would result in higher explosion pressures and rates of pressure rise than other fuels 2 3 5 Possibility of detonation Hydrogen air mixtures have a greater propensity to detonate than mixtures of air with other more common flammable fuels Detonations cause much more damage and are far more dangerous than ordinary explosions deflagrations However due to the rapid dispersal characteristics of hydrogen this is only likely to occur in a confined or congested space 3 GENERAL AND HIGHER LEVEL REQUIREMENTS Guidance given in this chapter is of a general nature and is taken from UK legislation and relevant European Community directives If
108. tries etc should also be considered Voids or openings between the room in which the fuel cell is enclosed and adjacent rooms into which combustion products could pass should be avoided The shared walls should be gas tight A check should be made that any automatic fire suppression system installed has been correctly specified for the room or space in which the fuel 14 cell and associated components are located All installations should comply with building and fire regulations For outdoor installations weather protection may be required Hydrogen storage cylinders and vessels located outdoors need to be protected from extreme temperatures below 20 C and above 50 C Permanently installed hydrogen vessels must be provided with substantial supports constructed of non combustible material securely anchored to firm foundations of non combustible material and protected from accidental impact e g from a vehicle Transportable compressed gas cylinders and vessels shall be secured against accidental dislodgement and protected from accidental impact The area around hydrogen installations should be kept free of dry vegetation and combustible matter If weed killers are used chemicals such as sodium chlorate which are a potential source of fire hazard should not be selected for this purpose 3 2 2 Ventilation Natural or forced mechanical ventilation can be used to prevent the formation of potentially explosive mixtures Natural ventilati
109. ugh they do not specifically focus on hydrogen The development of a standard specific to the performance and testing of hydrogen detection apparatus is underway ISO Technical Committee 197 WG13 Further information on regulations codes and standards relating to flammable gases and hydrogen is published in Chapter 6 of the HySafe Biennial Report on Hudrogen Safety and some useful regulations codes and standards are also listed in Appendix 1 Detection techniques sensor positioning alarm levels sensor maintenance and calibration are discussed in Appendix 4 4 6 FIRE PRECAUTIONS Fire precautions are relevant for all aspects of the fuel cell installation from the hydrogen generation processing storage and piping to the fuel cells A fire can often lead to an explosion and by the same token an explosion can initiate a fire It is important therefore that a fire and explosion risk assessment be carried out as a single exercise that considers all the fire and explosion hazards that can arise Fire precautions are often referred to as process fire precautions PFP and general fire precautions GFP PFP are special precautions that are required for the work activity being undertaken to prevent or reduce the likelihood of a fire occurring or to limit the extent of the fire GFP are those basic measures taken to ensure people s safety in the event of a fire e g general measures to prevent fire means of escape provision of fire extin
110. uld be taken that vents do not release hydrogen adjacent to walls or along the ground as this may increase the extent of the flammable cloud or flame Safety separation distances where a release is foreseeable during normal operation should be determined on a case by case basis Separation distances should be measured horizontally from those points in the system where in the course of operation an escape of hydrogen may occur The most recent version of an appropriate code should be consulted for additional information on the appropriate use of separation distances In circumstances where it is not practicable to use minimum separation distances an acceptable situation may be achieved through the use of fire resistant barriers fire compartments fire resistance room sealed appliances appliance compartments or other hydrogen safety engineering or risk reduction techniques For all indoor locations the installation should comply with all applicable building regulations particularly as they relate to heating and electrical appliances fuel storage systems conservation of fuel and power protection against pollution and more 25 4 3 2 generally to securing reasonable standards of health and safety for people in or about buildings and any others who may be affected by buildings or matter connected with buildings For all indoor fuel cell locations liquefied and gaseous hydrogen storage should either be located outside in the open air in
111. utdoor commercial industrial and residential applications using fuel processing technologies It applies to packaged self contained or factory matched generation systems with a capacity of less than 400 m h that convert the input fuel to a hydrogen rich stream of composition and condition suitable for the type of device using the hydrogen e g a fuel cell Input streams include one or a combination of the following fuels 21 e natural gas and other methane rich gases derived from biomass or fossil fuel sources e fuels derived from oil refining such as petrol diesel and LPG alcohols esters ethers aldehydes ketones and other hydrogen rich organic compounds and e gaseous mixtures containing hydrogen Part 2 of the standard dealing with procedures to determine the efficiency of these types of generator is under development ISO has also published a standard ISO 22734 1 2008 on hydrogen generators using the water electrolysis process for industrial and commercial applications It covers the construction safety and performance requirements of packaged or factory matched generators for both indoor and outdoor use Hydrogen generators that can also be used to generate electricity such as reversible fuel cells are excluded from the scope of the standard Part 2 of the standard covering generators for residential applications is under development with publication expected in May 2010 Hydrogen fuel cells such as PEMFC and AFC usu
112. way that prevents networks from suffering unacceptable degradation of service when used under normal operating conditions In the UK Technical Note G83 1 1 covers the connection of small scale generators to local power distribution networks 35 5 PERMITTING ROUTE Currently there is no formalised route for the approval of a hydrogen and fuel cell stationary installation Guidance on installation can be found in BS EN 62282 3 3 20087 The permitting route required for a particular installation should be proportionate to the scale and complexity of the installation Domestic or residential installations are likely to require a simpler permitting route than a commercial or industrial installation and for this reason different permitting routes are proposed for the two types of installation The approval checklist below is intended to apply to both new build and retro fitted installations 5 1 OUTLINE APPROVAL CHECKLIST FOR COMMERCIAL INDUSTRIAL INSTALLATIONS 5 1 1 Step 1 risk assessment Undertake a risk assessment to identify the hazards and the measures to be implemented to eliminate or mitigate their effects The principal hazards will be fire and explosion ones see 4 4 and 4 6 but other hazards e g electrical pressure and weather for outdoor installations related also need to be considered The hazards arising throughout the lifetime of the installation have to be covered by the assessment This would include those hazards

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