winsteam user`s manual
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1. Transport properties are not available in the wet region Specific heat is not available at the critical point Sonic velocity and isentropic expansion coefficient are not available in certain wet areas ERR HLOW 2100 Enthalpy too low The input enthalpy places the point at a temperature that is too low for the input pressure ERR HHIGH 2200 Enthalpy too high The input enthalpy places the point at a temperature that is too high for the input pressure ERR SLOW 2300 Entropy too low The input entropy places the point at a temperature that is too low for the input pressure ERR SHIGH 2400 Entropy too high The input entropy places the point at a temperature that is too high for the input pressure ERR NOCONVERGENCE 2500 Internal error An error occurred within the steam property calculation routines even though the inputs were within the allowable range This could be the result of a convergence failure in an iterative function Call Techware if this error occurs WinSteam Version 3 2 User s Manual2. GENERAL APPROACH All applications acquire steam properties by using the same set of forty three functions In most applications the functions are called by name In DeskTop Steam the appropriate functions are called automatically according to your on screen selections Each user of spreadsheets or programs you write using the steam property functions must have his own copy of WinSteam You are not licensed to distribute any of the WinSteam files without permission from Techware In Excel 1 2 3 Mathcad Visual BASIC and your own Window s programs the functions provided by WinSteam can be used within equations just like each application s built in math functions The functions can even be nested Each function returns a single floating point result The functions require either one or two inputs to identify the state point and an extra parameter to designate the unit set and other options Subsequent sections of this chapter describe the calling syntax and other considerations in using the functions within supported applications The following table summarizes the forty three functions together with their inputs and outputs Function Input s Output StmPT Pressure Saturation Temperature StmTP Temperature Saturation Pressure StmTQH Temperature Quality Enthalpy StmTQS Temperature Quality Entropy StmTQV Temperature Quality Specific Volume Stm
3. Plus 6 0 Use the Math Choose Function menu selections to open the Choose Function window Scroll down the Function name is box to find all the steam functions listed in alphabetical order The Returns box will describe the input arguments and the return value WinSteam Version 3 2 User s Manual Chapter 2 Using the Steam Property Functions Page 6 for the function that is selected Pressing the Insert push button will copy the function to your worksheet with placeholders for each function argument In Mathcad 8 use the Insert Function command menu selections to open the Insert Function window Select the Engineering category in the left hand pane of that window and select the desired function in the right hand pane Press the Insert push button to copy the function call into your worksheet 2 2 4 Using WinSteam from Visual BASIC The steam property functions can be used directly in your Visual Basic programs just like the built in functions Before the functions can be used however they must be declared as functions and Visual BASIC must be told where to find them This can all be accomplished by including a DECLARE statement for each of the steam property functions in either the Form code or in the Global code The DECLARE statement must include the name of the function the dynamic link library where it can be found TSTEAM32 DLL and the list of arguments which must all be passed by value ByVal A sample DECLARE statement
4. Pressure Entropy Temperature StmPSH Pressure Entropy Enthalpy StmPSV Pressure Entropy Specific Volume StmPSQ Pressure Entropy Quality StmPSC Pressure Entropy Specific Heat StmPSW Pressure Entropy Sonic Velocity StmPSG Pressure Entropy Isentropic Expansion Coefficient StmTEMPIT Temperature 1968 scale Temperature 1990 scale StmTEMPTI Temperature 1990 scale Temperature 1968 scale StmVER None Version serial no For C prototypes of the functions see the Stm32Proto h file in the Programming subdirectory of the WinSteam directory created on your hard disk by the installation program 2 2 USING THE STEAM FUNCTIONS Theoretically a point can be uniquely identified by specifying any two of the six thermodynamic properties In most practical applications however pressure and one other variable are known The functions contained in WinSteam are limited to such situations Supported combinations are P ressure and T emperature P ressure and Ent H alpy P ressure and Entropy S P ressure and Q uality wet region only T emperature and Q uality wet region only To obtain the properties of saturated water or steam use the pressure quality or temperature quality functions with quality set to 1 for saturated vapor or O for saturated liquid 2 2 1 Using WinSteam from Excel WinSteam 3 2 supports only 32 bit versions of Microsoft Excel As of this writing available 32 bit versions include Excel
5. To column will display the properties at the end point If you did not enter efficiency as one of the input variables the section efficiency will be calculated for you In addition the WinSteam Version 3 2 User s Manual Chapter 3 Using DeskTop Steam Page 16 expansion energy the energy converted to shaft power and the steam rate will be calculated The units for these results will be consistent with your input units but you may change the units from the drop down list box below the values You may change any of the data and repeat the calculation as required When you are satisfied with the result you may copy that state point back to the current point on DeskTop Steam s main window by pressing the Close and Copy to Current Point button There you can label and store the point is desired If you do not wish to use the expansion state point just press the Cancel button 3 7 USING THE HELP SCREENS The Help menu offers extensive on line help for DeskTop Steam The About item in the Help menu presents the version and serial numbers of your copy of WinSteam 3 8 ERROR MESSAGES When input values are out of range or any other errors occur a message box is displayed describing the error The calculated fields will not be updated until the error condition is resolved 3 9 EXITING DESKTOP STEAM You may exit DeskTop Steam by using any of the standard methods for closing Windows applications These include the follow
6. in the WinSteam library to actually perform the calculations The AFSTEAM add in can use any of the unit systems described in section 2 3 Different unit systems can even be mixed in the same spreadsheet 2 2 3 Using WinSteam from Mathcad The WinSteam add in for Mathcad is a self registering dynamic link library DLL All that is required for Mathcad to access the functions is that the add in file MDCSTM32 DLL be located in the MATHCAD USEREFI directory Whenever a WinSteam function is used Mathcad will automatically load and register the function The WinSteam add in for Mathcad allows the use of any of the unit systems described in section 2 3 Mathcad however allows only pure numbers without units to be passed to and from user defined functions such as these calls to WinSteam The last argument in each function call is the unit set designator and can use values as described in section 2 3 The other arguments to the functions must be numbers without units whose values are consistent with the selected unit set The SAMPLES subdirectory to the WINSTEAM directory created on your hard disk contains a sample Mathcad file named EXAMPLE MCD which makes typical calls to the steam property functions and illustrates the use of the unit set designator Although on line help for WinSteam is not directly available from within Mathcad Mathcad does recognize the WinSteam functions and assists user in assembling calls to the functions In Mathcad
7. the ENTER key to calculate all corresponding state point property values Notice that the ENTER key performs two different functions depending on what you are doing Once you begin typing any text in an I O box DeskTop Steam is in the edit mode While in the edit mode pressing the ENTER key causes the text in the I O box to be evaluated If the evaluation is successful the edit mode is cancelled If you are not in the edit mode pressing the ENTER key is equivalent to pressing the Compute button If you have just finished typing data in the last I O box that requires input data then you must either press the ENTER key twice to compute the properties once to accept the data in the I O box and a second time to give the Compute command or else just click the Compute button with the mouse 3 5 STORING STATE POINTS You have the option of labeling and storing state points for future reference You can store any number of points in the DeskTop Steam calculator This collection of state points can be saved as a DeskTop Steam project file In addition you can print the state points in a tabular form or copy them to the clipboard where they can be transferred to another application such as a spreadsheet program or word processor After calculating a state point the focus is shifted to the state point label box DeskTop Steam will automatically label the point in a sequential manner as Point 1 Point 2 etc but
8. you probably will want to rename the point with something more meaningful to you such as Main Steam or Turbine Exhaust You should keep the names short if you plan on printing the data or else the label may not fit in the printed column Some users prefer to enter the label before calculating the point If you do so and the label is unique DeskTop Steam will not change your label When you are satisfied with the label press the Store Point button and the values displayed for the Current Point will be added to your collection of points The state point that you have just stored will be displayed in the right most column of DeskTop Steam You can view any of the stored points using the drop down list box at the top of the Stored Points column DeskTop Steam requires all stored points to have a unique label If you try to store two points with the same label DeskTop Steam will query whether you wish to replace the stored point which has the same label with the current point If not you should rename the current point and try to store again WinSteam Version 3 2 User s Manual Chapter 3 Using DeskTop Steam Page 15 To use a stored point to calculate another point use the drop down list box to select the stored point you want then press the Recall Point button The values of the stored point will be copied to the Current Point column You may then change one or more parameters and recalculate a new state point You can also repl
9. 2 F for lower pressures Any attempt to calculate steam properties at temperatures above these points will generate this error T3 h Es R TLOW 1100 Temperature Too Low R PLOW 1300 Pressure Too Low A Es WinSteam does not handle thermodynamic properties below a pressure of 0 088 Psia or a temperature of 30 F ERR PHIGH 1200 Pressure Exceeds Program Limits WinSteam will accept a maximum pressure of 15700 Psia Any attempt to calculate steam properties at pressures above this point will generate this error WinSteam Version 3 2 User s Manual Appendix WINSTEAM DLL Error Codes Page 19 ERR PLOWSAT 1300 Pressure too low for saturation ERR TLOWSAT 1100 Temperature too low for saturation ERR THIGHSAT 1900 Temperature too high for saturation ERR PHIGHSAT 1900 Pressure too high for saturation There is no saturated state at pressures or temperatures above the critical point 3200 11 Psia 705 10 F or below the triple point 0 088 Psia 32 018 F Outside this range two properties other than quality are required to define a state point ERR CRITCONVERGENCE 1 500 Failed to converge within critical region All property calculations near the critical point are iterative Find a temperature volume combination that matches the requested inputs This error indicates a failure of thi
10. 3 1 OVEIVIOW e M 11 3 2 Input Combinations and Calculation sssssssse eee 12 3 3 Unit SSIS Teile E 13 3 4 CalCulatiniG State PO UMS d m 14 3 5 Storing State ONS P 14 3 6 Steam Turbine Expansion Tool sss nennen nennen enne 15 3 7 Using the Pelp Screens raean onm eet detenta ecu M stub uoce DR aaaea aeara 16 3 8 Error Messages uoce aenar ae enaa Eaa Duae p eo Deb Rte aeu 16 3 9 Exiting DeskTop Stea us oc Ee e nee era tte to to abe ERI raced PR ELS RIEN ARM RR RIED 16 SPEED AND ACCURACY CHARACTERISTICS sss 17 4 1 Speed of Calculations eene e p eerte Pr nex eer Ea agen E E aun 17 4 2 Accuracy or Calculallgris s eco tte atero edel ct tienda tees 17 APPENDIX STEAM DLL ERROR CODES Chapter 1 Introduction Page 1 1 INTRODUCTION WinSteam provides a library of steam property functions for Windows applications based on the formulations published by the International Association for the Properties of Water and Steam IAPWS WinSteam includes forty three accurate functions which normally use the IAPWS IF97 formulations but at the user s option can use the 1967 IFC formulations In January 1999 the American Society of Mechanical Engineers ASME declared that the 1997 formulations should be used for all future work The 1967 formulations however may be used for analyses involving previously de
11. 7 and Excel 97 Office 2003 and Office 2007 You must load the XLSTM32 XLL add in to access the steam property functions from Excel Loading this add in brings the functions into memory and links them to Excel You load the XLSTM32 property functions into Excel using the Add in Manager Use the Tools Add Ins menu selection to start the Add In Manager In Office 2007 click the Office button then click the Excel Options button then select the Add ins tab and click the Go button at the bottom If installed using the default values the file XLSTM32 XLL should be in the OFFICE LIBRARY directory and the Add In Manager will show that WinSteam for Excel is available If you do not see WinSteam for Excel click the Browse WinSteam Version 3 2 User s Manual Chapter 2 Using the Steam Property Functions Page 4 button and find the file XLSTM32 xl It should be in the C Program Files Microsoft Office OfficeXX Library directory where OfficeXX is the latest Office version installed Click the check box next to WinSteam for Excel and press OK The Techware copyright notice will appear in the status bar each time the add in is loaded Once selected this way using the Add in Manager the functions will be loaded automatically each time you start Excel If you wish to unload the functions use the Add In Manager and uncheck the box labeled WinSteam for Excel Thereafter WinSteam for Excel will not load until you select it again us
12. TQC Temperature Quality Specific Heat StmTQK Temperature Quality Thermal Conductivity StmTQM Temperature Quality Dynamic Viscosity StmTQW Temperature Quality Sonic Velocity StmTQG Temperature Quality Isentropic Expansion Coefficient StmPQH Pressure Quality Enthalpy StmPQS Pressure Quality Entropy StmPQV Pressure Quality Specific Volume StmPQC Pressure Quality Specific Heat StmPQK Pressure Quality Thermal Conductivity StmPQM Pressure Quality Dynamic Viscosity StmPQW Pressure Quality Sonic Velocity StmPQG Pressure Quality Isentropic Expansion Coefficient StmPTH Pressure Temperature Enthalpy StmPTS Pressure Temperature Entropy StmPTV Pressure Temperature Specific Volume StmPTC Pressure Temperature Specific Heat StmPTK Pressure Temperature Thermal Conductivity StmPTM Pressure Temperature Dynamic Viscosity WinSteam Version 3 2 User s Manual Chapter 2 Using the Steam Property Functions Page 3 StmPTW Pressure Temperature Sonic Velocity StmPTG Pressure Temperature Isentropic Expansion Coefficient StmPHT Pressure Enthalpy Temperature StmPHS Pressure Enthalpy Entropy StmPHV Pressure Enthalpy Specific Volume StmPHQ Pressure Enthalpy Quality StmPHC Pressure Enthalpy Specific Heat StmPHW Pressure Enthalpy Sonic Velocity StmPHG Pressure Enthalpy Isentropic Expansion Coefficient StmPST
13. VERVIEW DeskTop Steam is an interactive replacement for tables of the thermodynamic properties of steam It eliminates the need for time consuming look up and interpolation It automatically calculates all unknown properties when a state point is defined by two known properties The program is flexible and designed to minimize keystrokes for common calculations DeskTop Steam allows you to enter any number of state points label them and store the collection of points for later reference You can print a table of stored points or copy them to the clipboard and paste them into your favorite spreadsheet or word processor DeskTop Steam is a standard Windows application including a menu and toolbar at the top of its window and a status bar at the bottom It employs common keystrokes and mouse movements to activate its various menus buttons check boxes input fields and list boxes For example the Tab key can be used to move among buttons and input fields Please refer to your Windows manual for a description of the fundamentals of the Windows interface The program uses the IAPWS IF97 formulations by default but you can select the IFC 67 formulations by selecting the Use IFC 67 command from the Tools Formulations menu The results of calculations appear on the screen almost instantly Major features of this program include consistency with IAPWS IF97 or IFC 67 values validity over full range defined by the ASME flexible interactive design ful
14. WINSTEAM USER S MANUAL VERSION 3 2 COPYRIGHT NOTICE The WinSteam software and manual are copyrighted and licensed for use by one user per copy purchased This manual and the software described in it are copyrighted with all rights reserved Under the copyright laws this manual or the software may not be copied in whole or part without written consent of Techware Engineering Applications Inc Techware Engineering Applications Inc grants permission to the purchaser to make a limited number of copies of the add in for backup purposes only provided that the copies are not in use at the same time as the original Additional reproduction of the add in is a violation of copyright law Violators will be prosecuted to the fullest extent of the law Copyright 1992 2008 Techware Engineering Applications Inc All rights reserved TRADEMARKS The following trademarks are used throughout this manual They are registered trademarks of the companies shown Lotus and 1 2 3 and IBM and IBM PC are trademarks of the International Business Machines Corporation Excel Windows Visual C C and Visual BASIC are trademarks of the Microsoft Corporation Mathcad is a trademark of MathSoft Inc 1 2 TABLE OF CONTENTS INTRODUCTION t iecescueGeux Go settore tH Eee eta rk En 6s uns Tn pie VI EDT WEE FOR yes EUR Cr RE ERE E uen ob or ba Cor OK PEE 1 USING THE STEAM PROPERTY FUNCTIONSGS sss 2 2 1 General Ap
15. X appears to the left of the box to indicate that new input data has been entered After a Compute command is issued successfully all I O boxes are interpreted as output and the red X s are removed To enter values choose the property by clicking on the desired I O box with the left mouse button or press the tab key until the desired box is selected If you wish to enter new data double click the left mouse button to select all the text in the box You may enter either a number or an expression in the box A number can be entered in either decimal or scientific notation The expression can be any valid arithmetic expression using the following operators add subtract multiply divide exponent parentheses WinSteam Version 3 2 User s Manual Chapter 3 Using DeskTop Steam Page 13 Arithmetic calculations can be nested to any level using parentheses An example of a valid expression is 100442 99742 2 5 which evaluates to 1000 506 When you are finished entering the number or expression in the I O box you may move to another control or else press the lt ENTER gt key In either case the number or expression entered in the box will be evaluated and its value will be displayed in the box If the input is accepted a red X will be displayed to the left of the box indicating that this is a new input value that is not consistent with the other values displayed If the text typed in the box cann
16. ace stored values with those in the Current Point by using the Replace Point button The stored point s label and all the property values will be replaced with those from the Current Point even if the labels are the same You can eliminate the stored point currently displayed in the stored point column by using the Delete Point button All of these storage operations can be performed from the Edit menu as well All state point values that you store will retain the properties calculated using the formulations in effect at the time of the calculation For example suppose you calculate a state point using the IF 97 formulations and store it then change the formulations to IFC 67 The stored point will retain the values calculated using the IF 97 formulations but any new point calculated or stored will be based on the IFC 67 formulations If you recall the point the current point will still show the IF 97 values If you execute a Compute command the current point will now be recalculated with the IFC 67 formulations using the two selected properties as input values Since you can change back and forth between the formulations the storage array may contain a mixture of points calculated with both formulations You may wish to add a notation to the state point label to identify the formulations used 3 6 STEAM TURBINE EXPANSION TOOL This tool opens a dialog box that is used to calculate a steam path expansion from the current state point to anot
17. ase on the IAPWS Industrial Formulation 1997 for the Thermodynamic Properties of Water and Steam which was published in Erlangen Germany in September of 1997 This paper provides the formulations for calculating steam properties in 5 different regions Region 1 is compressed liquid region 2 is superheated steam region 3 is the critical region region 4 is the saturation line and region 5 is the high temperature superheated region In each region the paper provides several test points printed to 9 significant digits For all the points printed for regions 1 2 4 and 5 WinSteam 3 2 matches the published values exactly when using pressure and temperature as the input values In the critical region the equations are based on temperature and volume instead of pressure and temperature Since WinSteam does not have a function that uses temperature and volume as inputs the comparison is made using pressure and temperature as inputs The WinSteam functions use iterative procedures to calculate the properties in region 3 and should not be expected to achieve the same level of accuracy In fact the WinSteam functions actually match most of the properties to the full 9 digits In the worst case the functions are accurate to 7 significant digits If you would like to review the results in detail or to run the test on your own system please visit our web site for more information In general greatest accuracy is achieved when temperature and pressure are th
18. d in the same spreadsheet 2 2 2 Using WinSteam from 1 2 3 You must load the add in file named AFSTEAM 12A to access the steam property functions from 1 2 3 When the add in is loaded into memory it establishes links between 1 2 3 and the WinSteam libraries Use the File Add Ins Manage Add ins menu selections to start the Add In manager Before you can use the WinSteam add in for the first time you must register the add in by pressing the Register push button If installed using the default values the file AFSTEAM 12A should be in the LOTUS 123 ADDINS directory and will be shown in the Register Add Ins window If you installed the file elsewhere you will have to use the Look in window to search for the file When you have located the AFSTEAM 12A file select it and press the Open push button The add in is now registered To load the add in after it is registered click on the path name that has the AFSTEAM 124A file A check mark will appear to the left of the path name indicating that the add in is selected Press the Done push button to complete the task Thereafter each time you start 1 2 3 the functions will be loaded automatically If you wish to WinSteam Version 3 2 User s Manual Chapter 2 Using the Steam Property Functions Page 5 unload the functions use the Add In manager and uncheck the add in Thereafter the AFSTEAM 12A add in will not load until you select it again using the Add In manager as described ab
19. e input variables Other combinations of inputs require iterative solutions which apply tolerances of about 0000001 9 WinSteam Version 3 2 User s Manual Appendix WINSTEAM DLL Error Codes Page 18 APPENDIX WINSTEAM DLL ERROR CODES If an error is encountered by a function during calculation of a steam property it returns a negative value 1000 or more negative This Appendix presents the error numbers together with an explanation of each possible error condition The header file STMERR H defines mnemonic constants for the error codes The mnemonics are listed below also The error codes listed below are accessible only from programming languages like C or Visual Basic The interfaces provided for Excel and 1 2 3 intercept these error numbers and return appropriate Excel or 1 2 3 error values This is done to avoid inadvertent use of an error value in a cell equation In Mathcad an error message is printed in a box near the function If you have developed programs using earlier versions of WinSteam be aware that the numeric values of the error codes has changed to accommodate the fact that some properties have negative values when using some of the new unit systems Nine new codes have also been added to make it possible to better identify the cause of an error ERR THIGH 1000 Temperature Exceeds Program Limits WinSteam will accept a maximum temperature of 1600 deg F for pressures greater than 1450 psia or up to 363
20. eeded In 1 2 3 no parentheses are needed The StmVer function returns a floating point number containing the information e g 3 212345 The first three digits indicate the DLL version number The next five digits make up your copy s serial number WinSteam Version 3 2 User s Manual Chapter 2 Using the Steam Property Functions Page 10 2 8 UPGRADING FROM PREVIOUS VERSIONS WinSteam 3 2 is directly forward compatible with all of Techware s steam property add ins for Excel introduced over the past several years Most users will not need to make any changes to existing spreadsheets WinSteam 3 2 also maintains the same general function set and calling conventions of various steam property add ins produced by Techware since 1989 So conversion of even your oldest spreadsheets is readily feasible For help in converting older spreadsheets please see the FAQ section of our web site The WinSteam add in for Lotus 1 2 3 97 does not allow optional arguments within the functions For this reason the unit set argument is mandatory with each function call If you are upgrading a file created with an earlier version of 1 2 3 for Windows and have not included the optional unit set argument the steam functions will return an error value You must edit each steam function call and insert the missing unit set argument to eliminate the error WinSteam Version 3 2 User s Manual Chapter 3 Using DeskTop Steam Page 11 3 USING DESKTOP STEAM 3 1 O
21. her state point at a lower pressure The first column identifies 5 thermodynamic properties P pressure T temperature Q quality H enthalpy S entropy and the units currently in use on DeskTop Steam s main window The second column labeled Expand From shows the properties of the starting state point which was copied from the current point on DeskTop Steam s main window The third column labeled To will hold the results of the expansion calculation You define the expansion process by specifying the conditions for the end point The box below the columns allows you to choose the input variables for the calculation Typically if you are trying to predict the performance of a steam turbine section you probably know the end point pressure and the turbine section efficiency You will notice that those are the only two I O boxes that are enabled for you to enter data If instead you are trying to analyze the performance of a turbine section from either a heat balance or actual plant data you will know the end point pressure and perhaps enthalpy temperature or quality if the endpoint is in the wet region Select the button that corresponds to the data you have and notice that only the I O boxes for your selection are enabled Enter the data in the I O boxes just as you did on the DeskTop Steam s main window and press the Compute button or the lt ENTER gt key The expansion calculation will be completed and the
22. ing e Click the upper left corner of its program window and select close from the menu e Selecting Exit from the File menu e Press Alt F4 keys e Click the X button in the upper right corner of the program window WinSteam Version 3 2 User s Manual Chapter 4 Speed and Accuracy Characteristics Page 17 4 SPEED AND ACCURACY CHARACTERISTICS 4 1 SPEED OF CALCULATIONS This section addresses the steam property calculation speed as measured within Microsoft Excel Performance within other applications is similar The time required to recalculate a spreadsheet is a function of many features of the computer system hardware and the nature of the spreadsheet Technically the time required to perform the calculations also varies depending on the variables used as inputs and the region of the state point Calculations near the critical point are slower than those in other regions Calculations that use pressure and temperature as inputs run the fastest However today s processors perform floating point calculations so quickly that they are able to perform any useful set of calculations involving steam properties instantly for all practical purposes For example we have found that a 350 MHz Pentium Il computer can execute in excess of 12000 function calls per second 4 2 ACCURACY OF CALCULATIONS The calculations performed by WinSteam have been checked extensively against the values published by the IAPWS in the paper titled Rele
23. ing the Add In Manager as described above Once the add in is loaded the steam property functions are available in the same ways as Excel s built in functions That is they can be typed into cell formulas or they can be inserted by pressing the fx button while creating a cell equation or using the Formula Paste Function menu selection In Office 2007 these can be found on the Formulas tab When using either of the two latter methods the steam property functions will be alphabetically sorted in a function category called Engineering Generally you can use any of the functions listed in Chapter 2 in any cell formula Be sure to prefix the function name with an character if it is the first or only item in a formula The line below presents an example of a call to a steam property function from Excel StmPTH a1 b1 Eng After installation the SAMPLES subdirectory to the WINSTEAM directory created on your hard disk includes a sample Excel spreadsheet named EXAMPLE XLS which makes several typical calls to the steam property functions Since the steam property functions make many floating point calculations they can add to a spreadsheet s recalculation time You may find it desirable to set recalculation to manual rather than automatic through the Tools Options Calculation menu selection The WinSteam for Excel add in can work in any of the unit systems or modes described in section 2 3 Different unit systems can even be mixe
24. is as follows Declare Function StmPT Lib TSTEAM32 DLL ByVal P As Double ByVal Units As Integer As Double The file named STEAMDEC TXT contains a complete set of declarations for Visual BASIC If you are using the WinSteam functions in an Excel Visual Basic module to create additional functions you should use a different name to declare the functions or else they will conflict with the functions in the XlStm xll add in In this case you must use the ALIAS keyword in the declaration to identify the true name in the DLL For example Declare Function MyStmPT Lib TSTEAM32 DLL ALIAS StmPT ByVal P As Double ByVal Units As Integer As Double The file named TSTEAMVBADEC TXT contains a complete set of declarations for Excel Visual BASIC With each steam function call your code should check to ensure that the values returned are greater than 1000 Return values of 1000 or smaller more negative indicate error conditions See the Appendix for a listing of error codes and their meanings 2 2 5 Using WinSteam from Windows Programming Languages The steam property functions in TSTEAM32 DLL can also be called from your own programs compiled to run under Windows Prototypes for all functions must be declared near the top of the source file This is most easily done by including using the include compiler directive the file named Stm32Proto h All files needed to support your programming applications ca
25. it Isentropic Non Dim Non Dim Non Dim Non Dim Non Dim Non Dim Non Dim Expansion Coefficient Velocity In all cases make sure the units used and produced by these functions are compatible with the unit system of any formulae you use Otherwise make further conversion part of the cell equation The selection of unit set is made with each function call by the use of an extra argument which designates the unit set see section 2 2 In addition to allowing selection of the unit sets described above the Unit Set parameter is also used to select which formulations to use see section 2 4 and to select the non iterative mode see section 2 5 Including the unit set argument with each function call allows the following important features 1 The user can include functions in both English and SI units on the same spreadsheet 2 Because the choice of unit set is recorded with each function used on the spreadsheet it insures that anyone using that spreadsheet will automatically use the correct unit sets The WinSteam add in for Excel allows two modes of operation In one mode the unit set argument is optional and the units default to English units if the argument is omitted In the other mode the unit set argument is mandatory If omitted the functions will return an error value WinSteam Version 3 2 User s Manual Chapter 2 Using the Steam Property Functions Page 8 The optional unit set mode was included to allow the use of
26. l choice of units used for each property quick response time on line help screens If you choose to use the IFC 67 formulations the high temperature range is not available because it is not defined under the older formulations In addition the sonic velocity property is not available when using the IFC 67 formulations DeskTop Steam also includes a turbine expansion tool which analyzes steam turbine expansion efficiencies If you input the efficiency it will calculate the end point if you input the endpoint it will calculate the efficiency The expansion tool also calculates the steam rate and shaft energy If installed using the default settings DeskTop Steam is started by simply clicking on its name icon in the TechwareEng Group appearing in the Windows Program Menu WinSteam Version 3 2 User s Manual Chapter 3 Using DeskTop Steam Page 12 3 2 INPUT COMBINATIONS AND CALCULATION DeskTop Steam arranges the display in a tabular format which remains constant although the program window can be resized You may sometimes find it convenient to make the program window smaller Each of the twelve rows in the table is dedicated to one of the thermodynamic pressure temperature quality enthalpy entropy and specific volume or transport properties specific heat dynamic viscosity thermal conductivity Prandtl number and critical velocity After recalculation the twelve fields contain values for steam or water at a particular state p
27. mnemonics just add 16 to the unit set number In this case the unit set number would be 16 0 for English plus 16 for fast formulations The fast formulations are not available with the 1967 IFC formulations If you include the fast formulation option with the old formulations or with any forward function it will be ignored 2 6 VALID RANGE WinSteam produces results for the full range identified by either the 1967 IFC or the IF97 formulations WinSteam allows pressures up to 16 000 Psia 110 32 MPa for both formulations The official IAPWS release cites a limitation in the IF97 formulations to a pressure of 100 MPa but ASME recommends the use of these formulations up to 110 32 MPa WinSteam allows temperatures varying between 30 F and 1600 F 1144 3 C when using the 1967 IFC formulations The IF97 formulations limit temperature to 1472 F 800 C for pressures above 1450 3 psia 10 0 MPa but adds a new region which extends the temperature range up to 3632 F 2000 C for pressures up to 1450 3 psia 10 MPa 2 7 VERSION AND SERIAL NUMBER There may be new releases of WinSteam to add features or to support new applications Each new release of WinSteam will have a different version number Every licensed copy of WinSteam also has a unique serial number You can identify the version of the WinSteam and serial numbers of your copy by using the StmVer function which takes no arguments In Excel an empty pair of parentheses is n
28. n be found under the WINSTEAM directory if you chose the default directory during installation You may also find it convenient to include the file named Stmerr h It defines mnemonic constants for the various error values returned by TSTEAM32 The compiled code should also be linked with the import library named TSTEAM32 LIB With each steam function call your code should check to ensure that the value returned is greater than 1000 Return values of 1000 or smaller more negative indicate error conditions See the Appendix for a listing of error codes and their meanings WinSteam Version 3 2 User s Manual Chapter 2 Using the Steam Property Functions Page 7 2 3 ALTERNATE UNIT SYSTEMS The WinSteam functions directly support two main unit sets English units and the International System of Units SI and two variants within each for a total of four unit sets The table below summarizes the units used for each parameter in either system Use the unit set name or number to identify which unit system to use in each WinSteam function call Letom ate Rma n Qm emm Customary Gauge UnitSetNumber O 1 d 3 4 s 6 Temperature F C F JK Jc c J Specific Heat Btu lb F kJ kg C Btu lb F kJ kg C kJ kg C kcal kg C kcal kg C Thermal Btu hr ft F Watt m C Btu hr ft F Watt m K Watt m C Watt m C Keal m h C Conductivity Viscos
29. ng blanks For example the string Engl would be accepted as a match and cause the function to use English units but the string En would not be accepted as a match as the function would return an error For Mathcad the unit set can only be entered as a number The following examples show several valid uses of the WinSteam functions with unit set arguments Function Called from Cell Formula STMPT 150 0 Note that both the input values and the return values must use whichever unit set is selected for a particular function For example if the function StmPT is used in Lotus 1 2 3 with SI units then the function expects the input value to be in units of bar and the return value will be in units of deg C 2 3 2 Selecting Operating Modes The WinSteam add in for Microsoft Excel allows two modes of operation as outlined above One mode makes the unit set argument optional defaults to English In the other mode the unit set argument is mandatory The operating mode is determined when the add in is loaded into Excel based on an entry in the Windows registry made by the WinSteam installation program The user chooses whether the unit set parameter will be mandatory or not during the installation process If need to change the selection arises simply re run the installation program WinSteam Version 3 2 User s Manual Chapter 2 Using the Steam Property Functions Page 9 2 4 USING THE IAPWS IF97 OR 1967 IFC FORMULAS T
30. nput values Otherwise the values will be converted and you will have to re enter them The first time the program is started the SI unit system is automatically selected You may choose any combination of available units for your default set Simply select the units you desire as described above and issue the Use Settings as Default command from the Format menu The next time you start DeskTop Steam your unit set will be used If you change units and then save a file those selected units will be restored whenever the file is opened If you wish to change the units back to your default units all at once issue the command Restore Default Settings from the Format menu You can change all the units to either standard English or SI units by issuing the English units or SI units command from the Format menu For an even easier method just press the Eng or the SI button on the toolbar WinSteam Version 3 2 User s Manual Chapter 3 Using DeskTop Steam Page 14 Make sure to always note the units displayed when using values from DeskTop Steam The program makes it so simple to change units that it can be easy to lose track of the units in use Unit system changes in DeskTop Steam do not affect use of WinSteam from any other applications e g Excel 1 2 3 etc 3 4 CALCULATING STATE POINTS When you have finished entering values for the selected input variables press the on screen button labeled Compute or
31. o instruct a WinSteam function to use the old 1967 IFC formulations instead of the default IF97 formulations append the character o or O to the unit set name For example to select English units using the 1967 IFC formulations the unit set argument would be EngO If you prefer to use numbers instead of the mnemonics just add 8 to the unit set number In this case the unit set number would be 8 0 for English plus 8 for 1967 formulations WinSteam has no functions returning sonic velocity or isentropic expansion coefficient using the 1967 IFC formulations If you invoke this option using one of these functions it will be ignored and WinSteam will use the IF97 formulations instead 2 5 NON ITERATIVE MODE The IF97 formulations include special inverse functions to calculate temperature when pressure and enthalpy or pressure and entropy are the input variables While these functions return good results they are not as accurate as the other forward functions As a result WinSteam normally uses these inverse functions as a first approximation then iterates to achieve the same level of accuracy as the other functions You can disable the iterative feature and instruct a WinSteam function to use just the inverse function by appending the character s or S to the unit set name For example to select English units using the fast formulations the unit set argument would be EngS If you prefer to use numbers instead of the
32. oint Five properties are commonly used in describing steam state points temperature pressure enthalpy entropy and quality Theoretically a point can be uniquely identified by specifying any two of the six thermodynamic properties This is seen on a Mollier diagram as the intersection of two lines which represent two variables In most practical applications however pressure and one other variable will be known Acceptable combinations are Pressure and Temperature Pressure and Enthalpy Pressure and Entropy Pressure and Quality wet region only Temperature and Quality wet region only Choose the desired combination of inputs by checking the corresponding combination of check boxes The program will not let you select invalid combinations Variables that cannot be combined with existing selections are grayed Uncheck one or more variables to enable other input combinations Enter values for the selected input variables then press the on screen button labeled Compute to calculate all corresponding state point values Pressing ENTER on the keyboard is equivalent to pressing the Compute button You can enter input data only for five of the thermodynamic properties including pressure temperature quality enthalpy and entropy The text boxes for these five properties are special dual purpose boxes called input output boxes or I O boxes for short If you enter a value in any of the I O boxes it is interpreted as input and a red
33. older files which may not have used a unit set argument If you do not need to use such files Techware recommends that you make the unit set argument mandatory You select this option during the installation process If you wish to change the mode run the setup program again If you have selected the optional argument mode and are creating a new spreadsheet it is recommended that you enter the unit set argument anyway This will assure consistency with future versions of WinSteam which may not allow optional unit set arguments In addition this documents the unit set you are using so that there is no confusion 2 3 1 Using Alternate Unit Systems The unit set argument is always the last input argument to the function call For the functions StmTemplT StmTempTl StmPT or StmTP it is the second argument for all the others it is entered as the third argument For convenience the unit set can be selected by entering either a number e g O for English units or 1 for SI units or a string e g ENG for English units or SI for SI units or reference to a cell which contains one of these values Ifa string is used it can consist of upper or lower case characters and may contain any number of leading blanks The function checks the first few non blank characters for a match e g 3 characters for ENG and 2 for SI If it finds a match the function checks the remaining characters for unit set modifiers and ignores any other characters includi
34. ot be evaluated to a number you will hear a beep focus will be returned to the box and the first offending character will be highlighted You must fix the error and try again If the expression you are entering is too long to fit in the I O box the box will temporarily increase in length so that you may view more of the expression When the edit mode for the I O box is cancelled the box will return to its original length If you wish to edit an expression typed in an I O box select the I O box and then issue the Recall Expression command from the Edit menu or press the F2 key The last number or expression entered in that I O box will be displayed and the I O box will be in the edit mode Note that the I O box retains the last number or expression entered even after a Compute command is issued As a result the value in the box may not reflect the value of the expression 3 3 UNIT SELECTION DeskTop Steam allows you to use any combination of units for input and output properties The units for each property can be set independently by using its associated pull down box To change a unit select its list box and scroll through the list of available units using either the keyboard cursor arrows or the mouse Whenever a new unit is selected the program converts the values displayed for that property in both the current point and the stored point value boxes Therefore when entering data it is best to first select the units and then key in the i
35. ove but it should be unnecessary to go through the registration process again Once the add in is loaded the steam property functions can be used in any cell formula by typing the function name in the same ways as 1 2 3 s built in functions If you need help use the 1 2 3 Help menu and select the WinSteam Help item This will launch an interactive help window which provides information regarding the functions and their usage When the add in is loaded the steam property functions are available in the same ways as 1 2 3 s built in functions That is they can be typed directly into cell formulas Generally you can use any of the 43 functions listed in section 2 1 in any cell formula simply by prefixing the function name with an character The WINSTEAM SAMPLES directory includes a sample 1 2 3 spreadsheet named EXAMPLE 123 which makes several typical calls to the steam property functions The line below presents an example of a call to a steam property function from 1 2 3 QStmPTH al bl Eng This syntax actually calls an add in function in the AFSTEAM add in These add in functions perform error checking and return an appropriate 1 2 3 error value e g ERR when necessary typically when input arguments are out of range or when too many arguments are supplied to the function 1 2 3 will not accept a cell formula that contains a function reference with too few input arguments The AFSTEAM add in functions themselves call functions
36. proach esie he rp EE EE HR ORbe FR rta EAT eM IRR cu UO ERE RS ERREUR ORAE 2 2 2 Using the Stesrm P UDICUO Ts ocidh nice erre se bdo Somme aah aod coc bee eal diit aera det ds 3 2 2 1 Using WinSteam from EXCel oai eM se Odette Seatac i ben Rabe to e fed etu anges 3 22 2 Using WinStearm TOM 192 3 accetto pero dero dee Fubuadezxe ig ea Bias ese Nue du ci dent 4 2 2 9 Using WinSteam from Mathcad cene iced ni e p Ra ees Ast RR RR ERE R E dan nEd 5 2 2 4 Using WinSteam from Visual BASIC iib ite pes amr taie diee en Toute ERE etri uus 6 2 2 5 Using WinSteam from Windows Programming Languages sese 6 2 3 Alternate Unit Systerris eei eee Tete b ee edd i pado td 7 2 3 1 Using Alternate Unit SySILeris cocer epe trio olor oe ep rer eue het ioa Ipsa o ot Leere dn 8 2 3 2 Selecting Operating Modes ciini tetto Gre Do ix tees bs La ateittatat iniu fe dki Ree iea pese 8 24 Using the IAPWS IF97 or 1967 IFC Formulas eee 9 2 5 Non Iterative Mode rr te teet tte rh Eee per hien peo rp ce CP ERU ER THER TERR TURA 9 2 6 Valid Ftang amp ostoc entes ee eser al scd lette s t at eu Rr eaten t 9 2 7 Version and Serial Nurnber botte e e ERA RE Lean t enean iria be e pde ede gae 9 2 8 Upgrading from Previous Versions eeeeeeseeeeeeeeeeeeeeeee eene nennen ennt en nnn nnens 10 USING DESKTOP STERN eie trt e e cons tate tnra dd eda Ente cu ta ero oae Fen tado aues 11
37. s iteration Contact Techware if this error occurs ERR NOTINRANGE 1500 Either temperature and or pressure are beyond range of the steam property routines For the thermodynamic properties WinSteam will accept only pressures in the range of 0 088 Psia to 15700 Psia For all pressures it will accept temperatures in the range of 30 F to 1600 F For pressures up to 1450 psia it will accept temperatures up to 3632 F ERR INTERNAL 1600 Internal error An error occurred within the steam property calculation routines even though the inputs were within the allowable range This could be the result of a convergence failure in an iterative function Call Techware if this error occurs ERR QUALWRONG 1700 Quality input is incorrect The steam property functions only accept input quality between 0 and 1 0 inclusive ERR PNOTSAT 1800 Pressure outside of saturation range The saturated state of water occurs only at pressures between the triple point 0 08865 Psia and the critical point 3208 1 Psia ERR TNOTSAT 1900 Temperature outside of saturation range The saturated state of water occurs only at pressures between the triple point 32 018 F and the critical point 705 10 F WinSteam Version 3 2 User s Manual Appendix WINSTEAM DLL Error Codes Page 20 ERR _NOTAVAILABLE 2000 Property requested is not available at the input conditions
38. veloped contract requirements You can use WinSteam 3 2 in either situation The WinSteam package includes DeskTop Steam an interactive steam property calculator and various add ins which allow the functions to be used as if they were built in to 1 2 3 for Windows Microsoft Excel and Mathcad Programmers can call the functions which reside in a dynamic link library directly from many Windows programming languages such as Microsoft s Visual Basic Visual C and Access Both the 1997 and 1967 formulations in WinSteam have been extensively tested and found to replicate published sources For a complete discussion of add in timings and accuracy see section 4 of this manual WinSteam supports the full ranges defined valid by each set of formulations The functions detect requests for calculations outside those ranges and return an error value The ranges in which the routines are valid are described in section 2 6 of this manual WinSteam 3 2 supports only 32 bit applications If you are using Windows 3 1 or 16 bit applications please contact Techware for other options The Setup program and the installation instructions contained in the WinSteam package guide you through installing the files you ll need for the applications you expect to use Example files to help you get started will also be installed WinSteam Version 3 2 User s Manual Chapter 2 Using the Steam Property Functions Page 2 2 USING THE STEAM PROPERTY FUNCTIONS 2 1
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