ASME's Mechanical Engineering Toolkit 1997 December

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STEAM93/PC Properties of Steam and Water Interactive Desk Reference NBS/NRC IAPS'84 Formulations "The most accurate properties of water and steam in the world" By: Benjamin R. (Ray) Strong, Jr. and IMPULSE Engineering 415 Arch Street San Francisco, CA 94132 (415) 239-0940 Voice (415) 229-2354 Fax Internet: 76260,1200@CIS.COM (weekly) Thermo@hooked.net (daily) ThermoRay@AOL.com (weekly) Copyright 1984 through 1994 Benjamin R. Strong, Jr. P.E. License Agreement This manual and software is protected by both United States Copyright law and international copyright treaty provisions. You are granted a 30 day trial license. If you use the software for more that 30 days you MUST purchase a license to continue using the program. One license is required for every copy of the program. If the program will be used on a network, an additional license is required for each additional person who uses the program. Your licenses registration is not extended to anyone else. You may not distribute your registration number and if your registration number is distributed, your license will be revoked. This version of STEAM93/PC is shareware. You may distribute this program to others for their evaluation. Each additional copy you distribute is also bound to a 30 day trial period beginning from their receipt. You may copy this software to your computer. Also, to protect your investment from loss, you may make archival copies for the sole purpose of backing up the software. Network License If more than one user will be allowed to use the software on a computer network at the same time, additional users need to be authorized by paying for an additional fee for each additional user. By computer network, we mean any configuration of electronically linked computers where two or more users have access to the same computer program. Requirements, Transportability and Compatibility STEAM93/PC will run on all IBM/PC's and compatibles with 356k of memory or above also running PC/MS-DOS 1.1 or above. A graphics card and video monitor that supports IBM standard text is required. An 80i87 NDP is strongly recommended: operation without an NDP may be excessively slow. STEAM93/PC may not function properly in every hardware/- software environment, particularly in modified versions of the operating system. Graphics characters showing on the screen may not be displayable on all printers. ACKNOWLEDGEMENTS IBM (TM) of International Business Machines, Inc. Microsoft (TM) of Microsoft, Inc. 1-2-3 (TM) of Lotus Development Corporation. Sidekick is a tradename of Borlund International. GETTING STARTED Check for Completeness The program is found as part of the self-extract compressed file STEAMDOS.exe. (If you're reading this manual, you've likely already expended this file.) Just execute it to uncompress the files. The files in the package are: STEAM.EXE The STEAM93/PC program DUMMY.DAT A practice data set DUMMY.PRN The practice data set for use by 1-2-3 STEAMAN.TXT This manual Before running the program, make a copy (see your DOS manual) and use the copy for general use and practice session. Notes on your System STEAM93/PC will run on many different color or monochrome monitors with composite or RGB signals, and the Compaq and IBM portables. It was written for MGA, CGA, EGA, Compaq, and compatible graphics cards. STEAM93 has been tested in a variety of 8086/8088/80286 and high-speed CPU enhancements including ultra-high-speed co- processor accelerator cards and machines. However, the addition of an 80i87 to your system will make much more difference than a faster or newer CPU. For best results, a color monitor is recommended: STEAM93 uses color enhancements to increase the information content and for ease on the eyes. If you have a Compaq with an external monitor, remember to turn it on using the Ctrl-Alt-< keys. The program will run with or without a NDP chip, but runs much faster with it installed. This especially applies to P- h, P-s, and some transports calls which can be quite time consuming. If you are using an 80i87, STEAM93 will use it extensively. This can be used as a test of the 80i87 - if an inconsistency or program abort occurs during calculation, it is our experience that this is most likely an 80i87 problem: that the 80i87 is operating too "hot", or at too high a speed. If you have a switchable system clock, try slowing the clock down. If problems occur with a cold/slow system, call us immediately. If the version of your program is copy protected, you will only be able to use the program on the diskette provided to you. We hope this doesn't provide too much of an inconvenience to you. If you have damaged the diskette, please send it back and we'll send you a new one. Post Processing the STEAM93 Properties Data For follow-on calculations, data logging, and/or plotting we suggest Lotus 1-2-3. This spread sheet program can be used to automatically perform some quite complex calculations. (More about 1-2-3 later.) You can also use 1-2-3 to convert STEAM93/PC data for use by dBASE-II/III. For on-line calculations, we recommend Sidekick. Table of Contents Getting Started Check for Completeness Notes on your System Post Processing the STEAM93 Properties Data Table of Contents List of Figures List of Tables INTRODUCTION About Steam93/PC Related Products About IMPULSE Engineering STEAM93/PC USAGE OVERVIEW Starting the Program Loading the Program Practice Session EXIT'ing, Ending your Session Screen Layout and Use Properties Screen Additional Transports Screen Messages and Indicators On-Line Helps Inputting and Deleting Data Inputting Property Data Inputting Property Combinations Copying Data Deleting Data F3 Key, Finding State Values Opps! = ESC and Recovery Calculation Options Critical Region Toggle Transport Calculation Toggle Printing Units USING THE STEAM TABLES Finding Saturation Values Isentropic Searches and Efficiencies Availability SAVING AND RETRIEVING YOUR SESSION DATA ON DISK Saving Your Session Saving To Your Default File Retrieving a Data File Merging Partial Data Sets USING STEAM93 WITH LOTUS 1-2-3 ENGINEERING NOTES Critical Mass Flux Speed of Sound in the Two-Phase Region Thermodynamic Quality The Very-Near Critical Region Range, Physical Accuracy, and Consistency REFERENCES Appendix A SERVICE AND WARRANTIES PRODUCT SERVICE LIMITED WARRANTY Figures 1.A Properties Screen Layout and Function 1.B Additional Transports Screen Layout and Function 2.A General Help Screen 2.B Input Help Screen Tables 1 Thermodynamic and Transport Properties 2 Range and Accuracy 3 Units Conventions INTRODUCTION About STEAM93/PC STEAM93/PC was written to provide the highest accuracy and highest consistency reference for the properties of steam and water available anywhere in a fast and easy to use form. Much concern and time was spent to make sure that annoying problems such as data overflow, format overflow, system lock- ups during difficult calculations,... will not occur, and protection against them is automatic. Also, knowledge of the state range is not required. Our goal is to make the process of using the program as comfortable, natural and unsophisticated as possible without burdening you with quirks of the solution techniques, system, machine, or programming languages. STEAM93/PC provides the state and transport properties shown in Table 1 to the accuracy estimated in Table 2. The exceptional accuracy is due to the following: -- Each and every property calculation is evaluated from the fundamental formulations. No approximations are introduced by using tables, interpolations, splines, curve fits, or other approximations. -- The fundamental state property solvers are the most accurate and most consistent formulation currently available anywhere. These are applicable over a much wider range than any other correlation [1, 3]. These solvers are based on the most recent internationally approved material from the International Association for the Properties of Steam. The formulations, approved as the "IAPS Formulation 1984", were developed by the US National Bureau of Standards and the National Research Council of Canada and have also been approved by the American Society of Mechanical Engineers through their Research Committee on the Properties of Steam (as members of the IAPS). In addition, the STEAM93/PC implementation has been written to take advantage of this correlation in some special ways: STEAM93/PC is verified to source data and independent parallel correlations to the greatest number of significant digits published in all available reference works, and throughout the entire range of applicability. The Gibbs condition for phase equilibrium is used for the calculation of saturation conditions and coexisting phases. In the very-near critical region, where even mainframe implementations have great difficulty, an optional correlation is available to accurately resolve property data. The range of applicability is extended to 100,000 Bars and 100,000░K. Full data precision is available to SAVE and spreadsheet files for accurate post-processing with the property data, or for data logging. STEAM93/PC includes transport and indirect properties from approved standards commonly used in engineering applications. To make STEAM93 more useful the general format is like a spread sheet for systems and component studies, with data copying, printable files for data logging, and other features. The development of STEAM93 for the PC began with the basic formulations and embedded them in a fault-tolerant environment for greater accuracy and transportability. This environment was then improved by use of the FORTRAN Addenda (also available from IMPULSE Engineering) which provides the screen, keyboard, and file management utilities. STEAM93 has been used in a variety of applications areas, ranging from power systems studies, meteorology, aerospace, component design, and pre-processing for fluid systems simulation programs. Please let us know of your application, and especially if you have questions or problems in using the program. Related Products IMPULSE Engineering has a number of products that can help you develop programs for science and engineering applications. You can receive more information by writing, calling, or e-mailing us at the locations shown on the cover sheet. Verification Package for STEAM93 This documentation describes the extensive verification and benchmarking for STEAM93. The document includes the plan, results, and output files used. STEAM93.DLL STEAM93.DLL allows MS-Windows developers and users of applications such as MS-Access, Win-Basic, MS-Word and Excel to access the NBS/NRC steam tables from within their application. Using MS-Windows Clipboard, OLE, and other resource, the steam tables can now be imbedded in any Windows application. STEAM93/Win This is a windows application that provides the same range of services as STEAM93/PC for DOS. Written specifically for the MS- Windows environment, STEAM93/Win allows Clipboard and real-time OLE connections to other applications and documents. STEAM93/PGM The STEAM93 correlations are available as FORTRAN subroutine source code for custom applications on non-IBM compatible platforms. The package comes complete with a Programmer's Reference manual, example source code, and structure charts and diagrams. A FORTRAN application front-end and benchmark data set are also included. FORTRAN Toolkits The FORTRAN Toolkits are libraries of routines for developing user friendly programs in the DOS & FORTRAN environment. The routines range from windowed graphics to string searches, from on-screen editing control to file management. Engineering Libraries IMPULSE Engineering distributes libraries of engineering data. These can be called from Windows programs or applications that access Windows dynamic Link Libraries (.DLLs). These libraries include Geometry, properties, and schedules of pipes and tubes Pressure drops in piping and components Valve and damper characteristics Psychometric calculations for water and steam Steam tables (see STEAM93.DLL above) Each comes complete with documentation and sample programs. About IMPULSE Engineering IMPULSE Engineering provides specialized consulting and software services in thermodynamics and mechanical engineering to the aerospace, environmental, and energy industries. Our mission is to provide or create the highest quality state-of-the-art technology to make our world a better place to live. Table 1 Thermodynamic and Transport Properties # Property Abbreviation Description (many of the standard symbols are unprintable) 1 Pressure p, Press p = T(s/v)u 2 Temperature T, Temp T = 1/(s/u)v 3 Specific Enthalpy h, Enthal h = u + pv 4 Quality x, Qualty (See Technical Notes) 5 Specific Volume v, SpcVol v = 1/r 6 Availability go, Avail go = h - Tos 7 Specific Entropy s, Entrop s = -(A/T)v 8 Specific Internal Energy u, IntEng u = A + Ts 9 Nozzle p/v p/v 10 Specific Heat Capacity at Constant Pressure Cp Cp = (u/T)v 11 Specific Heat Capacity at Constant Volume Cv Cv = (h/T)p 12 Dynamic Viscosity ╡ IAPS'75 13 Conduction Heat Transfer Coefficient K, HtTran IAPS'85 14 Speed of Sound Cs, w,SndSpd 15 Isothermal Bulk Modulus B|T, BulkM|T BT = 1/k 16 Hemholtz Function A, Hemhlz A = u - Ts 17 Gibbs Function g, Gibbs g = h - Ts 18 Prandtl No. Pr, Prandtl Pr = Cp╡/K 19 Critical Mass Flux W*/A* W*/A* 20 Isentropic Exponent -, Gamma - = -v/p(p/v)s - = 1/a p 21 Kinematic Viscosity u ,KinVisc u =v╡ 22 Isobaric Compressibility ▀ , Comp|p ▀ = (1/v)(v/T)p 23 Isentropic Compressibility _ , Comp|s _ = -(1/v)(v/p)s 24 Isentropic Bulk Modulus B|s, BulkM|s Bs = 1/a 25 Free Convection Coefficient ▀nc, NatCon ▀nc = gb/u2 26 Thermal Diffusivity a, ThrDif a = Kv/Cp 27 Surface Tension s, SurfTn IAPS'75 28 Static Dielectric Constant _, Dielec IAPS'77 29 Isothermal Compressibility k, Comp|T k = -(1/v)(/p)T 30 Compressibility Factor Z Z = pv/RT (1) Calculated directly from the IAPS'84 Hemholtz function and it's derivatives [1,3], not necessarily from the equation shown. When an IAPS release date is shown, the formulation is from that IAPS specification. (2) In the 2-phase region the critical velocity V* is substituted for Cs. (3) Calculated assuming p, v, ... are TOTAL conditions. Table 2 Range and Accuracy PROPERTY RANGE ACCURACY (1) / NOTES Pressure 0 < p < 10,000 Bars IAPS'84 p < 30,000 Bars IAPS Extrapolations / (3) p < 100,000 Bars STEAM93 / (4) Temperature 0.01 < T < 1,000░C IAPS'82 / (2) T < 2,773░ IAPS Extrapolations / (3) T < 100,000░C STEAM93 / (4) Specific Volume 0 < T < 600░C, v(p,T) 0 < P < 500 Bars; Liquid 1 part in 10,000 (0.01%) Vapor 1 part in 1,000 (0.1%) General: T < 1,000░C, p < 10,000 Bars 10 parts in 10,000 (0.1%) Anomalous Region 2 parts in 100,000 0.002%) Metastable States "... very good ..." Vapor Pressure 0.01 < T < Tcrit 12 parts in 100,000 (0.012%) Specific Enthalpy of Vaporization " 2 parts in 10,000 (0.02%) Specific Enthalpy 1 < p < 5,000 Bars h(p,T) = p_h(1,T) 5 < p 5,000 Bars h(p,T) = [5+2(p-5)]_h(1,T) / (5) Specific Heat at Constant Pressure p < 1,000 Bars Generally 1% Dynamic Viscosity [2] 0 < T < 800░C Generally 1% / (6) 0 < p < 1,000 Bars Useful Range: T < 100░C and p < 10,000 Bars T < 560░C and p < 3,500 Bars Thermal Conductivity [2] 0 < T < 800░C / (6) 0 < p < 1,000 Bars Notes: (1) Accuracy is taken from References [1] and [2]: conservative summary of high error estimates based on comparisons with test measurements. Reference [1] has a very complete review of accuracy and should be consulted if range-specific accuracy information is required. (2) International Practical Temperature Scale of 1968 (IPTS '68) (3) Extrapolation of fundamental equation as agreed upon by the IAPS. [3] (4) Convergent/Consistent/Reasonable upper limits of calculation with no accuracy estimates proposed or attempted. (5) _h(1,T) is the uncertainty in dh at T and 1KBar. (6) Within the uncertainty of the test measurements. [2] STEAM93/PC USAGE OVERVIEW The STEAM93 program is used like a spread-sheet program with fixed form and functions of the data. The following sections will present an overview of the program's functions and usage. The easiest way to become familiar with the program is to load the sample session and just play with the options and capabilities. Remember to use a copy of the program for this, and not the original diskette! Starting The Program Loading The Program (1) "Boot" (start-up) your system (if not already on) and insert the STEAM93/PC diskette into the drive you want to use. (2) Just as you normally would, use DOS to set the default disk to the drive where you put the program diskette e.g., if the program diskette is in drive B and the prompt on the display shows A:> then type in B: and hit the carriage return key (Enter key). The DOS prompt should now show B:> (3) Type in STEAM and hit the Return key (Enter). After a few seconds, the screen will fill and a pair of square brackets, [ ], will appear to define a cell for input. That's it. From here on you're in STEAM93/PC. For a Help screen, reminder for what keys control the program, hit F10. To print that page, turn on your printer and hit the PrtSc key. Use this as your reference until you can remember how the special keys work. Practice Session For practice, read in the data file found on the diskette. To do this, hit the F6 key (this is the file read key) and type in the file name, dummy.dat. Then hit *Enter and wait until the data reprints on the screen. From here on, enter or delete data or practice with the various functions. EXIT'ng Ending The Session To exit back to DOS, just hit Ctrl+Home (hold down the Ctrl key and hit the Home key at the same time). (It's a good idea to save your session first.) If the data currently used by the program is not the same as the SAVE file, the program will ask you to verify if you want to exit without saving the current data. This will give you an extra chance to SAVE your data. Screen Layout And Use The STEAM93/PC program uses four screens to express itself - two screens of data (shown in Figures 1.A and 1.B) and two Help screens (Figures 2.A and 2.B). Use of the two data screens is similar for all of STEAM93/PC's capabilities as discussed in the following sections. Properties Screen When you start-up a session you'll see the screen shown on Figure 1.A. This is the main screen for all water properties operations. There are eight columns, labeled "Pt n", referring to State Points, for process studies. To the right of the screen there are two columns for property names and units labels: these labels apply to each column and cell in the row. The rows of properties for each of the 8 different State Points are totally independent "calculators". Each of these spaces are called "cells", just like a spread sheet. The cell you are working on is identified by the blinking (red) brackets. Movement for data entry and such is done using the cursor controls on the keypad (to the right of the keyboard). A second screen, shown in Figure 1.B contains additional transport data. This is accessed as discussed in a following section. Some of the units have coefficients, or exponents with the units name. This is intended to be read as a literal suffix to the number showing in the cell: don't invert the sign, just assume that it is a multiplier to the number showing. Additional Transports Screen In addition to the main screen of property and transport data, there is an additional page of data shown in Figure 1.B. You can access this page by hitting PgDn on the keypad. The data layout for this screen is the same as the properties screen discussed above. You can use the cursor to move around this screen, and access most other program functions except number input and calculate. When you are ready to return to state operations, just hit PgUp. Messages and Indicators While you are working with the screen, take special note of the top line. You will see four words which indicate where you are and what to do (see the General Help screen or Figure 2.A). Mostly, keep track of the "Wait" indicator when it appears: the program is working on something until "Inactive Any Key" appears on the top line. As you work more with the system you'll find these helpful in assuring that the program has done what you want. Except for file I/O, you shouldn't have to wait long. On the top line you'll also see an indicator for the cell location, as (n,y) where n is the state point number and y is an abbreviation for the state property. When data for the property and state point is available, the number will also appear here. (If the number to 8 places doesn't immediately appear, move the cursor away from the cell and back to the cell. It should then appear.) The time of day and the date are shown to the right of the screen on the top and bottom lines. These are for your reference as you use the program and are also written to the print and save files for data logging or checking for the right file. During the use of the program you will also notices changes in the intensity or the color in screen items. More about these later. Figure 1.A Properties Screen Layout and Function STEAM`93(6,h)= .27245044E+04 Properties Operations Inactive any Key 15:37:24 ----------------------S T A T E P O I N T S ( Water )--------------------- PROPERTY UNITS\ Pt 1 Pt 2 Pt 3 Pt 4 Pt 5 Pt 6 Pt 7 Pt 8 Press: Bars 100.000 100.000 100.000 Temp: C 311.031 311.031 311.031 Enthal:KJ/Kg 1407.28 2724.50[2724.50] Qualty: .0E+00 1.00000 1.00000 SpcVol:m^3/Kg .001452 .018025 .018025 Avail: KJ/Kg 489.733 1191.05 1191.05 Entrop:KJ/Kg C 3.35912 5.61395 5.61395 IntEng:KJ/Kg 1392.75 2544.25 2544.25 Nozzle: p/v 68862.8 5547.71 5547.71 PROPERTY UNITS\ Pt 1 Pt 2 Pt 3 Pt 4 Pt 5 Pt 6 Pt 7 Pt 8 Cp: KJ/Kg C 6.12439 6.89730 6.89730 Cv: KJ/Kg C 3.05600 2.99751 2.99751 DynVis:e-6Pa-s 81.8295 20.2664 20.2664 HtTran:mW/m C 526.976 76.3337 76.3337 SndSpd:m/sec 843.401 474.303 474.303 Bulk|T:Bars 2444.25 54.2385 54.2385 Hemhlz:KJ/Kg -569.58 -735.31 -735.31 Gibbs: KJ/Kg -555.06 -555.06 -555.06 PROPERTY UNITS\ Pt 1 Pt 2 Pt 3 Pt 4 Pt 5 Pt 6 Pt 7 Pt 8 KEYS Soln: Analy. Analy. Analy. AT Regn: SatLq SatVp SatVp F10=Help!, F1/F2=Copy, F3=Calc, ^F4=Calc.all, F5=Save, ^Home=Quit 11/ 6/1992 Figure 1.B Additional Transports Screen Layout and Function STEAM`93(6,P)= .18312173E+01 Transports Reference any Key 15:41:49 PROPERTY UNITS\ Pt 1 Pt 2 Pt 3 Pt 4 Pt 5 Pt 6 Pt 7 Pt 8 Prandl: .95100 1.83122[1.83122] Wc/A: kg/m^2s 108640. 15491.1 15491.1 Exp|s: 48.9840 1.24803 1.24803 KinVis:mm^2/s .118830 .365312 .365312 Comp|P:1/ C .003847 .008263 .008263 Comp|S:1/Bars .000204 .008013 .008013 Bulk|S:Bars 4898.40 124.803 124.803 NatCon:1/mm^3C 2671.60 607.217 607.217 ThrDif:mm^2/s .124952 .199491 .199491 SurfTn:N/m .011863 .011863 .011863 Dielec: 18.7849 1.33296 1.33296 Comp|T:1/Bars .000409 .018437 .018437 Z: .053861 .668573 .668573 PROPERTY UNITS\ Pt 1 Pt 2 Pt 3 Pt 4 Pt 5 Pt 6 Pt 7 Pt 8 -------------------------------------------------------------------------------- ----------------------------- IMPULSE Engineering ------------------------------ ----------------- STEAM`93/PC v3.1 (C) 1992 B.R.Strong,Jr.,PE. ----------------- -------------------------------------------------------------------------------- PgUp to return to properties. _ On-Line Helps By hitting the F10 key, the program will switch to one of the Help screens. During non-input operations, a Help screen that has memory "joggers" for the keys and special functions of the program will appear. During input, a different Help is available which describes special input and editing keys. If you need more information than is on the two Help screens, please refer to this manual. To return from Help to your prior operation, just hit any key. Also note the bottom line during normal operation which has the most common keys, and is used for messages and prompts for file information. Figure 2.A General Help Screen STEAM`93/PC v3.1 Help Reference Inactive any Key (time) Mode of Operation---+ ª ª Operations Status--+ ª User Prompt---+ STEAM9X NBS/NRC-IAPS`84 Steam Tables KEY RESULT / Function ª KEY RESULT / Function ª F1 Copy cell into Xtemp. ª Esc Abort Process. F2 Copy Xtemp into cell. ª F3 Find St.Pt. Properties. ª Del Delete data at this cell. F4 Find Props at ALL St.Pts ª Alt+D Delete ALL data for Pt. F5 Open File. ª F6 Save File. ª PgDn Transports Screen 2. F7 Save File as ... ª PgUp Retn To States Screen 1 F8 Print to 1-2-3. ª Alt+T Toggle Transport Calc.s F9 Change Units. ª Alt+C Toggle Critical Region. F10 Help!. ª Ctl+Home Return to DOS Notes: [ ] denotes current cursor (cell) location; move it using the keypad. To input data, just type in the number and enter it with a return <CR>. When 2 properties are input, hit the F3 key to calculate the others. Use F1 and F2 (Xtemp I/O) for copying an entire cell. Note the UNITS and POWER (e▒n) are a LITERAL SUFFIX to the cell value. Next key is processed on return. Indicates data is different from SAVE file. -> Figure 2.B Input Help Screen STEAM`93/PC v3.1 Help Reference Inactive any Key 15:47:26 -------- INPUT HELP -------- STEAM`92 input is similar to a line editor and DOS. You enter data by just typing the data and hitting the <CR>. Like DOS, the prior data is stored in a buffer from which you can copy using F1 and/or F3. If you wish to edit the prior data, hit F3 and a line editing mode is active. This mode is also active when a syntax error is found. To exit without any modifications, the `opps` functions are provided. STEAM`92 will check your inputs STROKE by STROKE for context and syntax ! KEY FUNCTION Esc Start over. If on col. 1, Esc an `opps` <CR> Enter data. On a syntax error, the cursor ID`s the problem and editing is turned on. <CR> on col. 1, is `opps`. F1 Copy 1 char. from prior data (buffer). F3 Copy remaining data from prior data (buffer). Editing turned on. Del Delete the character to the right. (Buffer moves to left.) BkSp Delete the character to the left. (Buffer moves to left.) Ins Insert a keystroke at the cursor location. (Buffer moves to right.) Ctrl+End Universal `opps`, available at any time. Notes `opps` Exit without any change of data or action. Edit Editing is turned ON by F3 or a syntax error. Editing is turned OFF by Esc. NumLock Toggle to allow number input from the keypad. Cursor is turned OFF. Any key to continue input. _ Inputting and Deleting Data Inputting Property Data The input and editing is quite natural and follows DOS, EDLIN, and word processors. Unlike those, STEAM93 will check the context of the data. To enter a number at the cell you're at (denoted by the brackets), just start to type a number. A small cursor (_) will appear at the left of the bracketed space indicating to go ahead and type in your data. (There will also be a prompt on the top line which indicates what type of input is being requested.) Just type in the number in any real (with or without a decimal point) or exponential (e, d, g) format and enter it with a carriage return, *Enter. Unlike most interactive programs, STEAM93 "buffers" your input data, checking the inputs character -by- character. Almost anything will work and the usual rigid forms are relaxed here. Data is entered with the usual carriage return key, *Enter. If the number is unacceptable for some reason, the editing mode is automatically turned on and the cursor is re-located to the offending digit as discussed in the following section. After successful entry, the program will modify the appearance of your input to provide the maximum number of digits of accuracy. This automatic formatting is for "looks" only - all of the information you input is stored in the computer, and will be echoed on the top line to 8 significant digits. You can also use Sidekick to input data by moving to the location where you wish to enter the number stored by Sidekick and hitting the key programmed to hold it. Refer to your Sidekick manual for such operations. All successful inputs are identified on the screen by an inverse color or intensity. If you find you cannot input data in a cell, it's because this property is not allowed as one of the two acceptable inputs available for finding property values. The following sections describes the individual key protocols. It's not as confusing as it appears, and follows DOS or standard word processing protocols. Normal Input The standard input is as discussed above - just type in the numbers and hit *Enter. Additional keys, similar to DOS and EDLIN, are available to help you with this: Esc 'Opps'. When on data column 1: Esc is an 'opps', returning without change of any kind. When anywhere else, Esc restarts the input process. F1 Character Copy. Like DOS and Edlin, this copies a single digit from the data shown prior to starting input. F3 Dump Buffer Copy. Like DOS and Edlin, this copies the remaining digits from the prior data and turns on the editing mode (see following section). Bksp Delete Character. Deletes the digit to the left of the cursor Ins Insert On/Off. Toggles on/off the insert function. If Ins is ON, the next input digit is entered and the buffer (prior data) is shifted right. Del Delete Buffer Item. Shifts the buffer (prior data) left (like DOS) F10 Help. The input Help screen. Any key is used to return from this screen. *Enter Enter Data. If there is an error, the cursor will move to the source of the error and editing is turned on. Editing Mode (F3 During Input or Input Error) If F3 is hit (or if the *<─┘Enter would not allow the data), the full editing is turned on and additional editing capabilities are available: Esc Restart. Restarts input and returns to non-editing (normal) input mode. A second Esc is an 'opps', restoring the screen and data. Bksp Delete Single Item. Deletes the digit to the left of the cursor (_) and closes up the data to the right. Del Delete Single Item. Deletes the digit over the cursor (_) and closes up the data to the right. Ins Insert On/Off. Toggles On/Off the Ins mode. If Ins is on, the next key struck is inserted above the cursor and the data is moved right to make room for it. * Right. Just moves the cursor (_) right. Ins mode is turned off. * Left. Just moves the cursor (_) left. Ins mode is turned off. Home Flush Left. Cursor is moved to column 1. Ins mode turned off. End Flush Right. Cursor is moved to the last significant (non-blank) digit. Ins mode turned off. Editing After an Error If the bell sounds after hitting *Enter to enter data, the number is unacceptable and the editing mode is automatically turned on. The cursor moves to the location of the offending digit or symbol, and you can edit just like a data string as discussed in the prior (F3) section. Editing the Previous Data To edit data showing on the screen, first hit a number to get into the input mode and then hit Esc once to get you back to column 1. Then hit F3 to re-print the previous data and turn on the editing mode. Once the editing mode is on, edit the data using the cursor and keys as discussed in the prior (F3) sections. Input Property Combinations You need not overly concern yourself too much with the valid input combinations allowed; STEAM93 checks them automatically. For your reference, they are: p and T Pressure and temperature p and h Pressure and enthalpy p and x Pressure and quality p and v Pressure and specific volume p and s Pressure and entropy T and x Temperature and quality T and v Temperature and specific volume Don't bother to memorize these, as the program allows only the acceptable combinations. Copying Data The F1 and F2 keys are used to copy data. Hitting F1 will store the number at the current cell (within the brackets) to internal storage. Hitting the F2 key will copy the number currently stored to the current cell. So, for repeating a number, enter the number in a cell, hit F1, move the cursor to the new locations, and hit F2. The number stored is the full 64-bit accuracy allowed by the machine, even though all of the significant digits may not appear. Output values provided from the program are to the full machine accuracy, so for consistency it is always better to reproduce a number using the F1 F2 sequence than to re- input it by hand. Full state consistency can be assured this way without being limited to the accuracy of your inputs digits. Note that the copying process is units dependent, so that copying vertically to another data type will likely yield a different magnitude. So copying data is best for horizontal copying between state points. Deleting Data Just hit the "Del" key on the keypad to delete the data shown at the cursor. If additional data is deleted it's because you may have deleted data which was one of your previous inputs. This is intentional for consistency. To delete an entire column (State Point) of data use Alt+D (hold down the "Alt" key and hit the "D" key). F3 Key, Finding State Values When any two primary state variables (i.e., p and T or others identified in Section 3.5.2) are available for a state point, just hit the F3 key. The inputs will be checked in context and the search for the other consistent state and transport properties. You need not concern yourself with the range or state region of your inputs, STEAM93 is smart enough to manage it alone and tell you what region your input / output is in. If the inputs are out of range, a message will appear on the lowest line echoing the property at fault. (This checking includes some pre- calculation in certain regions so it may take a second.) Simply reinput the number and use F3 again. While calculation is proceeding the messages on the top line will often change and the clock will continue to run. Calculation continues until the screen has reprinted the data for the state point and the "Inactive" message appears on the top line. Some calculations, notably p-s and p-h calls, take quite a bit time. As long as the clock changes time every few seconds or so, the program is still trying to find the consistent state values. If you do not have an 80i87 installed in your machine, please be patient, and wait for the "Inactive" message to appear on the top line. If you wish to abort calculation before completion, hit the Esc key. OPPS! = ESC and Recovery The Esc key is used to end the current operation of the program. During input of a number or filename, hitting Esc will end input, and restore the original data. During calculation of a state point, hitting the Esc key will abort the calculation and return you to normal operation. Calculation Options There are two toggles you can use to reset calculation options of STEAM93 and control the handling of the very-near critical region and the calculation of transport properties: Critical Region Toggle In the very-near critical region, STEAM93 has an optional calculation method to evaluate properties and transports. When you start the program, this toggle is "off" as denoted by the letter "A" (for Analytic) appearing under the "Keys" note near the bottom-left of the screen. In this default mode, the canonical fundamental equation (IAPS'84) is used throughout the calculations. To access the alternative critical region method, hit Alt+C (hold down the Alt key and hit the C key). This toggle is noted on the screen as a "C" (for Critical) instead of the "A". This critical region formulation and correlations will be substituted for the IAPS'84 formulation whenever the state point is found to be in the very-near critical region. (More about the this region and how it is defined and handled in a later section.) To turn off this critical region detail, just hit the Alt+C key combination again. Transport Calculation Toggle If you have no need of the transport properties or specific heats, you can turn off their calculation. When you start the program, this toggle is "on" as denoted by the letter "T" appearing under the "Keys" note near the bottom-left of the screen. In this mode, the transport properties are automatically calculated. To turn off automatic transport property calculation, hit Alt+T (hold down the Alt key and hit the T key). Calculation of the transports will then be skipped, as denoted by a "N" in place of the "T". To calculate the transports, you need only to reset the toggle by repeating the Alt+T combination. Note that if you have an 80i87 installed in you PC that the transport calculations do not take much time compared to state point calculations. Most of the time is spent printing to the screen rather than in calculation. Printing You can print out the screen at any time by using the shift- PrtSc key (upper case and PrtSc keys at the same time) as provided by your operating system. The files written by STEAM93 are also printable using the DOS "TYPE" command, but the output will not be as readable. The DOS PrtSc command takes precedence over any STEAM93 operation so the program will pause until the printing has finished. Make sure your printer or spooler is on or DOS will wait forever for the printer to be available. Units Units are summarized in Table 3 with the abbreviations appearing on the screen. Common units and abbreviations are used and should be self-explanatory. For a few properties, notably the viscosity, there is an exponent ( e-6 ) preceding the unit. This, and the unit, are to be interpreted as a literal suffix to the number. As you would expect, if the data itself has an exponent (i.e., e-9), the exponents in the number and in the dimension are added (in this example, summing to e-15). To switch back and forth from SAI to English/Engineering units, just hit F9. All conversions are automatic. Conversion factors all use 8 significant digits and are consistent with ANSI/NBS Standards. USING THE STEAM TABLES As well as an accurate reference for properties and transports at state points, STEAM93/PC offers a variety of convenient calculations capabilities. A few of these are described in the following sections. Finding Saturation Values As you might expect, data right on the saturation lines is found using pressure and quality (p and x) or temperature and quality (T and x) as inputs. Quality is input as either 0 for saturated liquid or 1 for saturated steam. (Also see Sections 8.1 and 8.3 for additional information.) Isentropic Searches and Efficiencies One of the most common uses of the steam tables is for observing isentropic processes and using efficiencies. Using STEAM93/PC, this process takes just a few seconds. For example, take an isentropic expansion process from StPt's (state points) (1) to (2) resulting from a nozzle or turbine. In this example p1 and T1 are known. First, p1 and T1 are input, and the F3 key is struck to calculate the remaining data for StPt (1). Then s1 is copied to s2 at StPt (2) (using the F1 key at s1 and F2 key at s2). The new pressure is entered at p2 and the F3 key is struck to calculate the remaining data at StPt (2). The resulting data at StPt (2) are the properties and transports at (2) from the isentropic expansion. This process can be rep-resented by: s1(p1,T1) s2=s1 y2(p2,s1) where y2(p2,s1) is any property at StPt (2). For an imperfect expansion process as for a turbine, an efficiency et, may be available for the process to discover data at p2 using StPt (3). For the expansion, this efficiency may be described as: et = (h1 - h3) / (h1 - h2) To find data for the inefficient expansion process (1) to (3), StPt's 1 and 2 are created as in the above. Then h3 is calculated using Sidekick or another calculator from: h3 = h1 - et( h1 - h2 ) and h3 is entered at StPt (3). p3 is copied from p2 (again using F1 and F2), and F3 used to calculate data at the StPt (3) for the inefficient process. Note that critical mass flux (assuming pn and vn are at total conditions) and critical velocity (assuming pn and vn are at local static conditions) are available to assist in sizing and flow calculations. Using the F1 and F2 copy sequence is recommended because the full 15 significant digits are copied and used for the calculation at the new state point - manually input will yield only 5 places or so of input accuracy and inconsistencies may appear. For a compression process like a pump, the sequence of solution is similar. The isentropic process (1) to (2) is resolved as for the compression process. h3 is then found from the pump efficiency: ep = (h2 - h1) / (h3 - h1) h3 = h1 + (h2 - h1) / ep and entered for StPt (3). p3 is copied from p2 and the new StPt (3) is found using the F3 key for the imperfect compression process. Of course, the analogous process can be used for any constant property process: isobaric, isochoric (constant density), isothermal,... Availability The (steady-flow) availability function is provided for the evaluation of equipment and processes. The availability function is defined as: go = h - Tos where: go = steady-flow availability function h = enthalpy To = environment absolute temperature (heat sink) = 273.15░C, is chosen for evaluation. s = entropy To evaluate the maximum work output for a reversible process between two states the difference in availability is used as: Specific Power = Power out / Mass Flow Rate Specific Power <= go1 - go2 The difference between the maximum possible useful work output and the actual work output is sometimes called the irreversibility of the process. By evaluating the availability and irreversibility, the primary sources of expensive energy waste can be identified and corrected. The irreversibility can be used as a measure of the gains achieved in improving performance. SAVING AND RETRIEVING YOUR SESSION DATA ON DISK The protocol for file names in DOS is so flexible as to give most programs problems. The protocol includes the disk drive (d:), the file name (filename), and an optional extension (.ext) put together as d:filename.ext. If the file you want is on your default disk (identified by the d>_ or d: prompt before you executed the program), then the disk drive need not be entered, resulting in filename.ext. As you may know from using other programs, DOS takes control on file name errors (illegal characters) or requests to disk drives which are unavailable (i.e., the door on the disk drive is open). This usually disrupts program execution and results in unrecoverable aborts. STEAM93/PC uses a number of protection devices to avoid most of these problems: filename inputs are checked for legal characters, the disk directories or local drives are checked to make sure the file is present (on reads), the drive name input is checked for legality,... This is to make sure that you can always save your session. When you hit a key signaling for file I/O, a prompting message will appear on the bottom line. For the entry, upper or lower case does not matter. Extensions (using a .ext at the end of the file name) are recommended. For data (save) files use an extension of .DAT, and the 1-2-3 output file uses .PRN (Lotus REQUIRES an extension of .PRN). Saving Your Session To save your data, just hit F5. On the bottom line a message and prompt will appear for you to type in the file name. Type it in and hit return. If you hit the key accidentally, use the Esc key to recover. The "Prompt" message on the top line will change after the read or write has been accomplished and reprinting of any new data is finished. Saving To Your Default File If you're saving to the same data file more than once, use the F8 key. If you've typed in a save file name once it is stored in the buffer and can be used any time later for the default. Data in the save file is in the STEAM93 SAI units set in printable ASCII form with time and date of creation suitable for archiving. Retrieving a Data File To retrieve a session, use the F6 key. You will be prompted for the file name as discussed above. Merging Partial Data Sets State points without data are not written to the SAVE file, and will not be reproduced / reprinted to the screen and not over-write data appearing for that state point. You can use this to merge SAVE files from different data sets. USING STEAM93 WITH Spreadsheets To write the property data to a file compatible with 1-2-3, just hit F7. The resulting file format is readable by Excel and Quatro Pro and other spreadsheets. As in the other functions to save and retrieve your session, a file name prompt appears on the bottom line. Make sure that you use a file name extension of .PRN for 1-2-3. When you are in 1-2-3, locate the cursor where you want the upper left hand corner of the STEAM93 data set to appear. Then use the /File Import Number (/FIN) selections from the 1-2-3 menu to access and enter the data file. Make sure to locate the 1-2-3 cursor at a new point so that it doesn't overwrite existing data: 35 rows by 10 columns should be anticipated. The .PRN file written for 1-2-3 use includes headers and dates as well as the complete number data set. The full accuracy of the data is stored in 1-2-3 even if it's not printed. If you wish to show more digits of data, use the 1-2-3 display commands (/WG, etc.). ENGINEERING NOTES Critical Mass Flux The critical mass flux is calculated by assuming the input intensive state properties are providing TOTAL (stagnation) conditions. This is the only property provided in this way: all others assume input intensive properties are at local static conditions. Speed of Sound in the Two-Phase Region In the two-phase region the speed of sound is undefined. In this region the critical velocity V*, calculated for isentropic process and equilibrium conditions, is substituted for the speed of sound. Thermodynamic Quality The thermodynamic quality, or vapor mass fraction, is generally calculated using specific volume. However, for p - h or p - s inputs in the saturated region enthalpy and entropy fractions are used instead as: p - h x = (h-hf) / (hg-hf) p - s x = (s-sf) / (sg-sf) other x = (v-vf) / (vg-vf) When a state search results in subcooled values, x will be retained at 0. Similarly, x for superheated vapor results will be set to 1. In the supercritical region, x may be 0 or 1. The "Region" note for the state point near the bottom of the screen will advise you of the region. Natural Convection Heat Transfer Coefficient This term is a portion of the nondimensional Grashof Number used for free convection heat transfer studies. The full term is: Gr = BETAnc * ( L**3 ) * ( T - Tinf ) where BETAnc = the term provided by STEAM'92 L = the dimensional length T = the local fluid or body surface temperature Tinf = the ambient fluid temperature These terms are dimensioned such that Gr is nondimensional. Where T - Tinf is large, it is recommended that this term (as well as the Nusselt number) be evaluated at (T+Tinf)/2. Units Coefficient Some of the units have coefficients, or exponents with the units name. This is intended to be read as a literal suffix to the number showing in the cell: don't invert the sign, just assume that it is a multiplier to the number showing. Cv and Alpha: The current release has incorporated new solvers for Cv and alpha (isentropic compressibility), in the 2-phase region. These solvers circumnavigate the calculational problems as well as accurate results. The Very-Near Critical Region Accurate and unconditionally consistent resolution of properties in the critical region is a major strength of the STEAM93/PC and /PGM implementations and has previously been a long standing problem even in main frame programs. For research purposes in the very near critical region an alternative, "Scaled Fundamental" formulation is provided. The analytic (IAPS'84) formulations are recommended and the default option. The region very-near the critical point is very difficult to evaluate by any general purpose formulation even on mainframe computers. The difficulty of calculation in this region is largely due to the flatness of Zq/ZT within a degree or so of the critical temperature. For the IAPS'84 analytic formulation, "It should be noted that state of the art measurements for this region are consistent only to within ... p/p = (2x10-4) g/g = (2x10-5) ... for the region ... 200 < p < 280 Bars 160 < q < 450 kg/m3 " (liberally paraphrased from [1]) As an option to using the IAPS'84 Formulation in this difficult to evaluate region, an alternative is available which uses the scaled fundamental equation recently recommended by members or the NBS and presented to the IAPS. "... the scaled fundamental equation is recommended in cases where it is important that the surface, and in particular its derivatives, display the physical behavior predicted by the modern theory of critical phenomena." [3] This scaled fundamental formulation is valid in the region: 644 < T < 693 K 200 < q < 420 kg/m3 This formulation is quite fast and provides a level of consistency difficult to achieve with the general fundamental equation. To remove potential inconsistencies in very-near critical two-phase and vapor applications the range of application of the scaled fundamental is adjusted upward slightly to: 645.37 < T < 693 K When the toggle is on for use of the equation (Alt+C has been hit and the "C" Key note is showing), the solution manager will check to see if the analytic result is in the applicable range for use. If it is within range, the scaled fundamental equation will be used to calculate all state and property values. When this formulation has been used, the Regn: note (for the state point near the bottom of the screen) will show "Criticl". Be careful when you are working immediately on/near the limits of the range of the scaled fundamental formulation. There has been no attempt to remove the discontinuity in data and derivatives at the boundary of the range. All values of the data are, of course, within the specified physical accuracy and consistency. However, the relative error change across the border of applicability can appear large. Range, Physical Accuracy, and Consistency STEAM93/PC was designed to provide the most accurate and consistent properties of steam available. STEAM93/PC has been benchmarked to be identical in all significant digits over the range of published data and tests or seven significant digits, whichever is MORE accurate. NO approximations have been introduced in the implementation of the IAPS'84 formulations. Table 2 is an overview of the stated accuracy and range of the IAPS Formulation 1984 and transport formulations. It is most significant that these are summaries of the comparisons with the physical data and not calculational accuracy. STEAM93 has been verified to all published significant digits throughout the ranges of the published data for these formulations. The differences found in real applications occur with comparisons with earlier less physically accurate formulations. A detailed analysis of the physical accuracy and comparison with other correlations can be found in References [1] and [4]. STEAM93/PC and /PGM were written for process studies as well as a standard properties reference. Therefore there is a heavy emphasis on consistency as well as very high accuracy. This consistency extends throughout the calculational range of the program and the through the discontinuities. You can test this consistency by inputting data for a state point using output data from another point. You should find, as we have, consistency to twelve significant digits. As changes to the industry standards are published (including the recent NBS publications), these will be incorporated if necessary. You will be advised of the new release and if changes have resulted which might change the accuracy or reliably of the STEAM93/PC property data. REFERENCES 1. L.Haar, J.S.Gallagher, & G.S.Kell, "NBS/NRC Steam Tables", Hemisphere Publishing Co., N.Y., 1984. 2. C.A.Meyer, R.B.McClintock, G.J.Silvestri, R.C.Spencer, "ASME Steam Tables", 5th Ed., ASME, N.Y., 1983. 3. J.Kestin, J.V.Sengers, B.Kamgar-Parsi, J.M.H.Levalt Sengers, "Thermophysical Properties of Fluid H2O", Amer. Chem. Soc., J. Phys. Chem. Ref. Data, Vol. 13, No. 1, 1984, (Reprint 242) 4. J.M.H.Levalt Sengers, B.Kamgar-Parsi, F.W.Balfours, J.V.Sengers, "Thermodynamic Properties of Steam in the Critical Region", Amer. Chem. Soc., J. Phys. Chem. Ref. Data, Vol. 12, No. 1, 1983, (Reprint 214) 5. W.C.Reynolds, "Thermodynamics", 2nd Ed., McGraw-Hill, N.Y., 1968. (Chpt. 8) 6. R.C.Reid, J.M.Prausnitz, T.K.Sherwood, "The Properties of Gases & Liquids", 3rd Ed., McGraw-Hill, N.Y., 1977. 7. Hendricks, R.C., Peller, I.C., and Baron, A.K., "WASP - A Flexible Fortran IV Computer Code for Calculating Water and Steam Properties", NASA-TN-7391, 11/1973. 8. T.Baumeister, E.A.Avallone, T.Baumeister III, "Mark's Standard Handbook for Mechanical Engineers", 8th Ed., McGraw-Hill, N.Y., 1978. APPENDIX A SERVICE AND WARRANTIES PRODUCT SERVICE The program is supported by: IMPULSE Engineering B. R. Strong, Jr., P.E. 415 Arch Street San Francisco, California 94132 (415) 239-0940 Office (415) 229-2354 Fax Internet: Thermo@hooked.net (daily) Internet: ThermoRay@AOL.com (weekly) Internet: 76260,1200@CIS.COM (weekly) New versions of this program, incorporating new features and capabilities, are regularly introduced as part of our new product development program. We will notify registered users whenever a new release is introduced. You have the option to purchase the new release or upgrade the version at a discount. This product has a limited warranty for 3 months from purchase or receipt. Please let us know if you have problems or wish a special configuration of the program. LIMITED WARRANTY IMPULSE Engineering warrants that: The program(s) and manual are complete and properly recorded; The User's Manual is substantially complete and contains all the information which is deemed necessary for use of the program(s); The program(s) functions substantially as described in the Manual; This limited warranty is for 3 months from purchaser's receipt of the software and is extended only to the original purchaser of the software. IMPULSE Engineering excludes any and all implied warranties, including warranties of merchantability and fitness for a particular purpose and limits the end-user's remedy to return of the software and User's Manual to the address above for replacement. IMPULSE Engineering specifically disclaims any other warranties, expressed or implied. In no event shall B.R.Strong,Jr. or IMPULSE Engineering be liable for any loss of profit or any other commercial damage, including but not limited to special, incidental, consequential, or other damages. Governing Law This warranty statement shall be interpreted, construed and governed by the laws of the State of California. (end)