Copyright: (c) 1996 U.S. Department of Commerce


Index

Click on the menu item for which you would like additional information.

General Information

Menu Commands

File Menu

Edit Menu

Options Menu

Substance Menu

Calculate Menu

Plot Menu

Window Menu

Help Menu

Windows

Saturation Table

Iso-Property Table

Specified State Points Table

Plot Window

Status Line


File Menu

The File menu contains commands to save, retrieve, and print results.  Click on the command for which you would like additional information.

Open Session

Save Session

Close Session

Save Tables

Print Setup

Print

Exit


Open Session

The Open Session command reads a file  previously saved with the Save Session command.  The Session files are identified by a .RFP filename extension.  The Open Session command restores the program to the state it was in when the Save Session command was issued.  Thus, the unit system, reference state, selected properties, fluid, and all tables and plots are restored.

The Open Session command can be accessed only if there are no table or plot windows open.  The Close Session command closes all windows and cause the Open Session command to be accessible.


Save Session

The Save Session command saves the current state of the program in a disk file with a .RFP filename extention.  This file can later be recalled with the Open Session command.  All current information is saved, including the unit system, selected reference state and properties, fluid system as well as all tables and plots.  You are asked if you want to save the session whenever the Close Session command is issued, or when you exit the program.


Close Session

The Close Session command deletes all tables and plots from the display and releases the memory they required.  You will be prompted to use the Save Session command before the windows are deleted.


Save Tables

The Save Tables menu command displays a dialog window that allows the data in one or more of the current tables to be saved to a disk file in ASCII format.  A delimeter selected by the user is placed between each value in a row.   Most spreadsheet programs understand the tab character to separate items in the same row and a carriage return to signify the end of the row.  When the data in this format are read from the file into a spreadsheet application, each value goes into a separate cell.

The existing tables are shown in a list at the left.  Click on the name of the table you want to save and then click the > button or more simply, just drag the name of the table from the list on the left to that on the right.  If you click the >> button, all of the tables are moved.  The data in the tables in the right list will be saved in a single file.  To remove a table from the right list, click on its name and then click the < button.


Print Setup

The Print Setup menu command brings up the standard Windows printer setup dialog,  which allows selection of the printer and printer options, such as landscape or portrait format.  The selected printer and options are applied to the output from the Print command.  This command need only be used when the default printer or printer options are to be viewed or changed.


Print

The Print menu command allows one or more of the tables and/or plots to be printed.  Use the Print Setup command before selecting the Print command If the default printer or printer options are to be changed.

The previously generated tables and/or plots are shown in a list at the left.  The table or plot in the foremost window appears in the right list.  Click on the name of the table or plot you want to print and then click the > button to move it from the left list to the right list.   (Alternatively, simply drag the name of the table or plot from the list on the left to the right list.)   If you click the >> button, all of the tables and plots in the left list will be moved.  To remove a table from the right list, click on its name and then click the < button.  The tables and/or plots in the right list are printed in the order in which they appear in the list.


Exit

The Exit command provides a graceful way to exit from the program (quit).  You are prompted to apply Save Session if it is not already saved.  Memory allocated by the program is released.


Edit Menu

The Edit menu holds commands to copy and paste information between applications.  Click on the command name for details.

Copy Table Data or Copy Plot

Copy with Headers

Paste

Select All

Delete Row


Copy with Headers

The Copy with Headers command copies a selected section of a table to the clipboard.  The descriptive column headings will be included with the numerical data.  If you do not want to have these headings included, use the Copy Table Data command.

To copy part or all of the data in a table, select the cells to be copied by clicking in the upper left cell followed by a click in the lower right cell with the Shift key held down.  Selected cells are displayed in inverse video.   Alternatively, use the Select All command to copy all of the cells in the table.

Tab characters are used as separators between the values copied to the clipboard.   A carriage return character appears at the end of each row.  With this format, the selected data can be pasted into most spreadsheet programs and word processors.


Copy Table Data


Copy Plot


Paste

The Paste command is used to import values of the independent variables.  This command is typically used in conjunction with a Copy command from a spreadsheet applciation.

Paste can be used only in the Specified State Points table, and then, only in the columns containing values of the independent variables.  These columns are easily identified by the [image] mark at the upper right of the column header.  The data are pasted from the clipboard.  Values in the same row must be separated by tabs.  A return character must be used to separate data in successive rows.  This format is the norm for data copied to the clipboard with a spreadsheet program.


Select All

Select All selects all of the cells in a table.  The selected cells are shown in inverse video.  They can then be copied to the Clipboard using the Copy Table Data  and Copy with Headers commands.


Delete Row

Delete Row allows a specified row to be permanently removed from the table.  This command is accessible only if a window displaying a table is foremost and it acts upon that table.


Options

The commands in the Options menu allow selection of the unit system, reference state, and properties to be calculated.  Click on the desired command for additional information:

Units

Reference

Properties

Save Current Options

Retrieve Options


Units

The Units command will bring up the Unit System dialog window shown below in which the units of each property can be specified.

Clicking the SI or English buttons will set all of the dimensions to standard SI or English units, respectively.

If the Mass basis button is selected, specific properties, e.g., specific volume, will be calculated on a per unit mass basis.  Alternatively, the Molar basis button will cause calculations to be done on a per unit mole (equivalent molecular mass) basis.

To change the individual units, click on the arrow to the right of the current unit setting.  A drop-down list of possible units appears.  Click on the desired unit.

The changes made in this dialog window only affect subsequent calculations.  The data in existing tables are NOT affected by the changes.

The currently defined unit system can be saved with the Save Current Options command.


Reference

The reference states for enthalpy and entropy are entered in the Reference dialog window shown below.

There are three common choices for the reference state upon which the values of enthalpy and entropy are based.  These three common choices are:

1.  Setting enthalpy and entropy to zero for saturated liquid at the normal boiling point.

2.  Setting enthalpy and entropy to zero for saturated liquid at -40°C

3.  Setting enthalpy = 200 kJ/kg and entropy to 1.0 kJ/(kg-K) at 0°C.

This command brings up a dialog window  from which the reference state can be selected.  The three choices indicated above are provided, along with a fourth option in which the reference values of enthalpy and entropy can be specified at specified temperature and pressure.

For mixtures, the reference choice can be applied to a mixture at the currently defined composition (as indicated in the Status line) or to each pure component.

The reference state choice is saved with other preferences when the Save Current Options command is issued.  It is restored to a previously saved option with the Retrieve Options command.


Properties

The properties dialog window, shown below, provides a check box for each of the properties that can be calculated with this program.

 If a check is shown in the box to the left of the property name, calculations are done for that property  and the values of the property are displayed in the tables.  To select or unselect a property, click the left mouse button in the box.

At the upper right, a set of radio buttons is provided for "Bulk properties only" or "Bulk liquid and vapor".  This choice is important only for mixtures.  If the Bulk, liquid, and vapor button is selected, the property values corresponding to the bulk phase, as well as for saturated liquid and vapor are displayed for each selected property in each subsequent property table to be calculated.

The currently-selected properties can be saved as defaults using the Save Current Options command.


Save Current Options

The Save Current Options command brings up the usual Windows file save dialog from which a file name for the preferences files can be chosen.  The preferences file is identified by a .PRF filename extension.  In the file are stored the choices made in the Units, Reference and Properties dialog windows.  In addition, the current fluid system, selected with either the Pure Fluid or Predefined Mixture command, is also stored.

The program reads the Defaults.PRF file at startup.  If you want to change the preferences which appear when the program is started, save your preferences in the Defaults.PRF file.  You can also define as many options files as you want and restore any one of them with the Retrieve Options command.


Retrieve Options

The Retrieve Options brings up a dialog window from which a  preference file (identified with a .PRF filename extension), previously stored with the Save Current Options command, can be selected.  The Units, Reference, Properties, and fluid system are changed to the specifications in the selected options file.

The Defaults.PRF file is automatically loaded at program startup.   Save the options you want to appear automatically in the Defaults.PRF file.


Substance

The substance menu holds commands for selecting and defining a fluid system.  The current fluid system is identified in the status line at the bottom of the screen.

Pure Fluid

Predefined Mixture

Define New Mixture

Specify Composition

Specify Mixing Parameters


Pure Fluid

The pure fluid dialog window shown below  lists all of the pure fluids in the database.  Select the fluid you want to investigate by clicking the mouse on the fluid name.  Click the Info button to display the Pure Fluid Information dialog, which provides critical constants and other property informati0n for the selected fluid.


Predefined Mixture

This command will display a list of the currently defined mixtures as shown below.

A number of prefined mixtures are provided with the program.   In addition, you can specify new mixtures consisting of up to five pure components using the Define New Mixture command.

Click on the mixture name to select a mixture.  Clicking the Info button will bring up the Mixture Information window in which the critical point information, components, and composition of the mixture can be viewed.


Define New Mixture

The Define Mixture command provides a means for defining a fluid system consisting of 1 to 5  components.

Select the mixture constituents  from the list on the left by clicking on the fluid name, and then on the Add button.  (Alternatively, simply drag a name from one list to the other by pressing and holding the mouse button on the name while sliding the mouse to the other list.)  That fluid then moves from the list on the left to the list on the right.  To remove a fluid from the right list, click on the fluid name and then click the Remove button.   The fluid(s) in the right list become the selected selected fluid system.

Clicking the Info button displays the

Pure Fluid Information for the currently selected pure fluid in either list.

After the OK button is selected, the Specify Composition window appears, in which the mass or mole fractions of the components must be specified. In addition, the mixutre can be given a name and optionally stored on disk for later use.


Specify Composition

The Specify Composition window  shown below serves two purposes.

First, it provides a means of specifying the composition of a fluid system consisting of more than one component.  The composition can be specified in terms of either mass or mole fractions.  The choice is made by clicking in the box containing the words 'Mass fraction' or 'Mole fraction' followed by clicking on the name of the desired base.  The composition of the components will be converted as appropriate.

If you click the mouse on the name of a pure component, the Pure Fluid Information dialog appears, providing property information for that fluid.

The mass or mole fractions must be entered for each component and they must sum to 1 if the "Normalize compositions to one" checkbox is unselected.  If the "Normalized compositions to one" checkbox is selected, the value of each mass or mole fraction is set to the entered value divided by the sum of the values.  This option is most convenient if you want to specify the composition of a mixture by specifying the mass of each component.

The second function served by this dialog window is that it provides an opportunity to store the fluid system so that it can later be selected with the Predefined Mixture command.  The name appearing in the Predefined Mixture window and the status bar at the bottom of the screen is entered in the mixture name field at the top.  The mixture name filed can be edited.  Click the Store button to save this information.  You can, if you wish, store a pure component with a different name (such as a trade name) in this manner.


Pure Fluid Information

This window shows the thermophysical properties for the selected pure fluid.  In addition, the window provides a choice of models for thermodynamic, transport, or surface tension calculations when more than one model is available.  Information on the model, its limits of applicability and reference citations are provided separately for the equation of state, viscosity, thermal conductivity, and surface tension.

Click on the tab at the bottom of the window to display property information for the equation of state, viscosity, thermal conductivity and surface tension.  If more than one model is available for any of these properties, the list box directly below the box containing information on the range of applicability of the model is activated.  Click on the arrow to the right of the box to display the available models.  The recommended model is identified with the term 'NIST Rec'.  Select the model to be used in the calculations by clicking on its name.

The literature citations describing the selected model are provided in the box at the bottom.  Some or all of this information can be copied to the Clipboard by selecting the text and pressing the Copy button.  The information can then be pasted into other applications.


Specify Mixing Parameters

The database applies mixing rules to the pure-fluid Helmholtz energies.  In some cases, it may be possible to improve the agreement between the calculated properties and  experimental measurements by altering these rules.  However, great care must be used in altering these rules, because they can greatly alter the calculated properties.

This command is not intended for the causual user.  It's sort of like the old joke regarding expensive cars.  If you have to ask what this all means, you should not alter any of the rules or values accessible from this command.

This command is accessible only if a mixture has been specified.  A dialog similar to that shown below appears.

The mixing rules are applied to binary pairs of fluids.  It is necessary to select the pair for which you wish to alter information.  The fluids in the currently-defined mixture are listed at the left.  Only one pair at a time can be selected.  Any others are dimmed.  To change the fluids, unselect one of the selected fluids by clicking on it, followed by clicking on the desired fluid.

Shown at the right is the currently-defined mixing rule for the selected binary pair and the associated parameter values.  There are several different rules to choose from, and this is done by clicking on the down arrow button at the right of the rule box.  The parameter values can be changed.   No error checking is provided on these values, so take care when changing the mixing rules.  Also, note that changing the mixing parameters, in general, changes the critical parameters associated with the mixture.

If the mixture consists of three or more components, there is an Apply button visible to the right of the values.  Clicking the Apply button accepts the mixing rules and values as displayed, replacing the stored values.  Then, the binary pair can be changed so that additional mixing rules can be entered.  The OK button accepts the mixing rules as shown, but it also dismisses the dialog.

The Reset button restores the mixing rules for each binary pair to their original (as shipped) state.

At the bottom of the dialog, documentation is provided briefly describing the mixing rule and  indicating the reference source of the data upon which it is based.  You can select part or all of the text in this box.  If any text is selected, the Copy button is enabled, so that the selected text can be copied to the Clipboard and pasted into another application.


Mixture Information

This window displays the critical point parameters and composition of the selected fluid mixture.  The composition can be viewed on either a mass or mole fraction basis.  To change the basis, click on the arrow to the right of box showing 'Mass fraction' or 'Mole fraction'.

The fluids comprising the mixture are displayed in the lower part of the window.  You can access specific information on any of these pure fluids by clicking on the fluid name.  This action causes the Pure Fluid Information window to appear.


Calculate

The Calculate menu holds commands for initiating the calculations of  thermodynamic and transport properties of the selected fluid system.   Two modes of calculations are provided with the following three commands.

Saturation Tables

Iso-Property Tables

Specified State Points

The first type provides properties at saturation or with a property held constant with temperature varying over a specified range. The second type allows the user to specify the independent variables.


Saturation Tables

There are several different types of saturation tables, particularly for mixtures. This command displays the following window from which a saturation table is chosen.

The saturation table is specified by selecting one item from each list.  (The liquid at bubble point and vapor at dew point options are not applicable for a pure fluid and are disabled.)   All of the tables, except those in which the quality is varied, provide saturated liquid and vapor state point information, identified by (l) or (v), respectively in the column headings.  The red dots in the example box graphically indicate which points will be calculated.  In the example shown above, liquid and vapor at a fixed temperature and the same composition are to be determined for a range of compositions.  The blue line connects points that will be displayed on the same row of the table.

After the OK button is selected, another window appears in which the range and increment of the property to be varied and the value of the property to be held constant (if applicable) are specified.  In this example, it is necessary to specify the temperature and the composition range, which is done in the following window.

The temperature is entered at the upper left.  The composition will be linearly varied from the condition indicated in the "Initial" column to that in the "Final" column using the number of points indicated at the upper right.  With 11 points, the composition of this binary system is varied from pure component 1 to pure component 2 with increments of 0.1 in the mole fractions.

After the OK button is selected, calculations are initiated and a table displaying the results appears.  The columns are initially shown in a pre-selected order and with a default format.  The format and column position of each column can be changed by clicking in the column header to bring up the Format and Column Position window.


Iso-Property Tables

Two properties must be specified to fix the state of a fluid system of specified composition.  The Iso-Property allows one of the properties to be held constant while the other is varied in a controlled manner.  The following window appears in which the constant and varying properties can be chosen.  Click on one property in each list.

After the OK button is selected, another window appears in which the value of the constant property and the range and increment of the varying property are specified.

 The table is generated when the OK button is pressed.


Specified State Points

This table allows the user to select two independent properties and, optionally, the mixture composition, to fix the state of the fluid system.  The remaining thermodynamic and transport properties corresponding to this fixed state can then be calculated.  The following window appears when this command is chosen.

Choose the independent properties by placing a check mark in the box preceding the property name.  Not all combinations of properties are supported.  If a property name is dimmed, it cannot be chosen with the currently-selected other property.  To  unselect a property, click in the check box.   To specify a saturated liquid or saturated vapor state, click the "Quality" button and enter 0 or 1, respectively, in the Quality column in the table which follows.

If the 'Enter data manually' button is selected, a table appears with the selected properties in the leftmost columns.   The values of the independent properties (and component compositions) can be entered in three ways (in addition to reading data from a file), as listed below.

1.	Values can be simply typed into the cells of the property table.

2.	Values can be automatically entered in a systematic manner by clicking on the triangle marker at the upper right of the column header.  This action brings up the Automatic Data Entry window.

3.  	Values can be pasted into the independent variable cells from another application, such as a spreadsheet.  Copy the values to the clipboard using the other application's Copy command.  Then, in the property database, click the mouse in the upper left cell in the table and select the Paste command.

Using the Specified State Points Table

Whether the independent properties are read from a file or entered manually, a table will appear in which the independent properties are positioned in the leftmost columns.   The words 'Enter value' will appear in a table cell for which independent property data have not be entered.  Press the Calculate button at the upper left of the table when the independent values are entered;  the state points are calculated and the table is filled in.

Note that you can then change the independent variables (which causes the calculated values in that row to be erased) and repeat the calculation process.  Calculations are done only for those rows in which the independent variables are specified and the calculations have not been done previously.  (You can force the program to repeat all of the calculations by pressing and holding the Enter key down.)

The column position and format of any column can be changed, if desired, by clicking on the column header.


Automatic Data Entry

The Automatic Entry dialog window provides a convenient method to enter independent property values into the Specified State Points table.  The columns containing the independent variables are identified by the triagular marker at the upper right of the column header.  Clicking on that marker accesses the Automatic Data Entry window.

The affected rows are displayed at the upper left.  By default, the changes will occur for all rows in the table.  The values can either be cleared or set, depending on the radio button setting.

The value to be placed in the first row of the selected row range must be specified in the "First Value" field.  Beneath this field is a second field in which the last value in the range, the increment, or a multiplier can be specified, depending on the selection shown in the drop-down control.  If "increment" is selected, the value of successive rows in the table are determined by adding the value in the increment field to the previous value.  Similarily, if "multiplier" is selected, successive values are determined by multiplying the previous value by the value indicated in the field.  If "final value" is selected, the variable is varied in uniform increments from the specified initial to the final values.

The independent values entered in the table must be in the unit system selected with the Units command.


Saturation and Iso-Property Tables

This table displays the results of the Saturation or Iso-Property calculations.  The appearance of the data and the column positions can be changed by clicking on the column header.  Any data in the data can be plotted by selecting the New Plot command.


Format and Column Position

The format of the data in each column is set to a  default style, which should be acceptable in most cases.  You can change the format of the data in the column by clicking the mouse in the column header.  This action will bring up the window shown below in which the format of the data in the column and the column position can be changed.

To change the format of the values in the column, click on the arrow to the right of the 'Style' field.  A list of 'Default', 'Fixed Decimal', and 'Float Decimal' is shown.  The Fixed Decimal option allows a fixed number of digits to be specified to the right of the decimal point.  The Float Decimal option allows the number to be displayed in engineering format with the total number of  decimals specified in the control appearing below the Style field.  An example illustrating the display format appears to the right of the word 'Format'.

To change the column position, click the up or down arrows until the desired column position is shown.  The positions of all other columns shift accordingly.


Read File Data

 Values can be read from an ASCII file stored on disk.  To enable this option, select the  "Read from File" button in the "Data Source" box at the bottom of the Specified State Points dialog window.  When the OK button is selected, an Open file dialog appears in which you may specify the file containing the independent property values.  Once a file is selected, the dialog appears as shown.

The window displays the first  50 lines of the selected files in the box at the top of the window so that you can see the format of the values in the file.  Lines in the file which begin with a non-numeric character, such as the * in the example above, are treated as comments and are ignored.

In the example considered here, temperature and pressure were chosen as the independent properties.  The selected properties are displayed preceded with a check box and followed by a control,  which allows the column to be specified.  It is not necessary to read all of the properties from the file.  For example, you can read the temperature by placing a check in the corresponding box but not read the pressure by omitting that check.

The "Read from data file" option also allows user data to be read from the file.  This capability is useful, for example, to compare experimental and calculated values of a property.  In the example above, the experimental thermal conductivity is in column 3.  The title 'Exp. TC' is entered by editing the box.  If a check mark precedes the name, the data in this column of the file is read and placed in a column in the Specified State Points table.  It can then be plotted, along with calculated values.  The user data columns are placed at the right of table in a default format.  However, the column order and display format can be changed using the Format Data controls.

If the composition of a mixture is to be varied in the table (by selecting the 'Varying as specified in table' radio button), a column for each component appears in the table in which the mole or mass fraction (depending on the setting in the Units dialog) is entered.   Note that it is necessary to enter only N - 1 of the mole fractions, where N is the number of components.  The composition of the last component is automatically calculated.  If the composition of all components is entered, it must sum to unity.


Plot Menu

The Plot menu provides commands to plot values in any existing table.  In addition, temperature-entropy (T-s diagram), pressure-enthalpy (P-h diagram) , and temperature-composition (T-x diagram)  and pressure-composition (P-x diagram) plots can be generated automatically.  The commands in this menu are listed below.  Click on the command name for more information.

New Plot

Overlay Plot

Modify Plot

Add Label

T-s diagram

P-h diagram

T-x diagram

P-x diagram

The appearance of the plot window can also be changed by the Plot Window controls.


New Plot

This command generates a new plot window in which the data in a column of a table can be plotted against data in any other column of the same table.  The number of allowable plot windows is limited only by available memory.  Use the "New Plot" command to generate a new plot window.  The Overlay Plot command plots data within an existing plot window.

Both the New Plot and Overlay Plot will bring up a dialog window similar to that shown above.   By default, it is assumed that data from the foremost table window are to be plotted.  However, the table from which the data are provided can be selected using the drop-down table list at the upper right.  It is also assumed by default that all of the data in the table are to be plotted.  If this is not the case, it is necessary to enter the starting and stopping row numbers in the "From Row" and "To Row" fields.

Select the variables to be plotted on the X and Y axes by clicking on their names in the respective lists.  Appropriate minimum, maximum, and interval values are supplied as the X and Y variables are selected.  However, these values may be changed before the plot is generated by modifying the default values, or later with the Modify Plot command.  Other plot options, such as the scale type, the line type, and the plot symbol, may also be selected in this dialog, or later with the Modify Plot command.  The smoothing option will fit a cubic spline through the data in order to produce a smooth curve.   This option will be dimmed if the data are not continously increasing or decreasing with respect to the X-axis variable.

The plot window has a number of controls which can be used to alter its appearance, as explained in the Plot Window section.


Overlay Plot

This command functions exactly like the New Plot command except that the additional data will be placed in an existing plot window.  Overlaid plots are assumed to use the existing scales for the ordinate and abscissa.  However, if the overlaid plot has values that cause part or all of the plot to be off-scale, a dialog window is presented which allows you to rescale the plot.

See the description of the Plot Window  for information on how to modify the appearance of an existing plot.


Modify Plot

The Modify Plot command can be used to change the appearance of an existing plot.

This command can be invoked by either double-clicking anywhere within the plot window or by selecting the 'Modify Plot' menu command.  In the latter case, the plot in the foremost window is affected.  If there is not a plot in the foremost window, and there is more than one plot, a dialog appears in which the plot window can be chosen.

A dialog similar to that shown below appears with controls to modify the color, symbol, line style of the plot as well as controls to alter the appearance and range of the scales on the abscissa and ordinate.  By defaults, the data points are plotted with a symbol and connected with lines;  either of these may be turned off.

For plot windows containing more than a single plot, a list of the plotted data sets is provided in the drop-down list box at the upper right of the dialog window.  Select the plot line for which the line type, symbol, color, and smoothing specifications are  to be applied.   These changes can only be made to one data set at a time.  If you want to change the characteristics for multiple data sets, you must click the OK button for each one and reenter the Modify Plot dialog.

The plot appearance can also be modified with the controls in the Plot Window.


Add Label

This command allows text to be placed on a plot window.  The plot window to which the command applied must be the foremost window.  After selecting the command, the following window appears.

The text to be placed on the plot window is entered in the edit field at the top.  Other text characteristics may be entered, such as the font, font size, and style.  When the OK button is clicked, the text appears at the center of the plot window.  It can then be dragged to any location in the plot window by pressing and holding the mouse button down on the text item while dragging it to its new location.

You can change the characteristics of the text item at any time by double-clicking on it.  See the Plot Window description for additional plot window controls.


T-s Diagram

A T-S diagram can be generated for the selected fluid system.  A dialog appears in which 0 to 8 pressures can be specified.  Isobars (lines of constant pressure) corresponding to these pressures are calculated and plotted on the temperature-entropy coordinates with the vapor dome if a check mark appears to the left of the value.  Additional isobars or other plots can be superimposed on this plot using the Overlay Plot command.  The appearance of the plot can be modified with the Modify Plot command.

Additional isobars or other plots can be superimposed on this plot using the Overlay Plot command.  Text to identify the isobars is automatically generated.  You can change or delete these text items or add additional text using the Add Label command.  The appearance of the plot can be modified with the Modify Plot command  and with the controls in the Plot Window.


P-h diagram

A pressure-enthalpy  diagram can be generated for the selected fluid system.  A dialog window appears in which 0 to 8 temperatures can be specified as shown below.

To specify a temperature, place a check in the box to the left of the value field by clicking on it, and enter  the value. Isotherms corresponding to these temperatures are calculated and plotted on the pressure-enthalpy coordinates.   If the 'Includes lines of constant entropy' control is checked, six isentropes will be placed on the P-h plot with labels indicating the entropy value.  The isentrope values are selected automatically and cannot be changed.

Additional isotherms or other plots may be superimposed on this plot using the Overlay Plot command.  Text to identify the isotherms is automatically generated.  You can change or delete these text items or add additional text using the Add Label command.  The appearance of the plot can be modified with the Modify Plot command and with the controls in the Plot Window.


T-x diagram

The T-x diagram command is applicable only for a binary system.  A dialog window appears in which 0 to 8 pressures can be specified.  Isobars (lines of constant pressure) corresponding to these pressures are calculated and plotted on the temperature-composition coordinates if a check mark appears to the left of the value.

Additional isobars or other plots can be superimposed on this plot using the Overlay Plot command.  Text to identify the isobars is automatically generated.  You can change or delete these text items or add additional text using the Add Label command.  The appearance of the plot can be modified with the Modify Plot command  and with the controls in the Plot Window.


P-x diagram

The P-x (Pressure-composition) diagram command is applicable only for a binary system.  A dialog window appears in which 0 to 8 temperatures can be specified.  Isotherms corresponding to these temperatures are calculated and plotted on the pressure-composition coordinates if a check mark appears to the left of the value.

Additional isotherms or other plots can be superimposed on this plot using the Overlay Plot command.  Text to identify the isobars is automatically generated.  You can change or delete these text items or add additional text using the Add Label command.  The appearance of the plot can be modified with the Modify Plot command  and with the controls in the Plot Window.


Plot Window

There are a number of controls on the plot window.

Change Plot Size

Place the cursor over the bottom right corner of the plot.  The cursor changes to a double-headed arrow to indicate that you are in the resize box. To resize the plot, hold the mouse button down while dragging the lower right corner of the plot to a different position.

Move Plot

Place the cursor anywhere within the window, except in the resize area.  Hold the mouse button down while dragging the plot to its new location.

Move Plot Labels

Plot labels can be  placed on the a plot window with the Add Label command.  The text is initially placed in the center of the plot window, but it can be moved to any position.  To move the text item, place the cursor over the text item.  Hold the cursor down while dragging the text to its new location.

Cross Hairs

Hold the Shift key down to display cross-hair lines on the plot.  The coordinates of the cross hairs (in units corresponding to the plot axes) are displayed at the top of the plot.

Modify Plot Characteristics

Double-click the mouse anywhere within the plot rectangle.  The Modify Plot dialog window appears, just as if the Modify Plot command were issued.


Window Menu

The Window menu contains the following three permanent menu items

Tile

Cascade

Retitle

Below these items, a menu item is provided for each table or plot window.  Selecting the menu item makes that table or plot the foremost window.


Tile

Tile resizes and repositions the existing windows so that all are displayed.  Scroll bars are provided, if needed.


Cascade

Cascade will arrange all of the currently-defined windows so that their title bars are visible, making it easy to select any of the windows.


Retitle

Each table and plot window is provided with a default title when it is generated.   This title is used in the Save Tables, Print, New Plot, and Overlay Plot dialog windows for identification.  You can change the default window title by entering an alternative in the edit space provided.


Help Menu

The Help menu holds commands for accessing the Help processor.  In addition, a command is provided to display the startup screen, which contains the program version number and other information

Help Index

Using Help

About REFPROP


Help Index

Help Index opens the Help file for this program to the index page.   The Help program can also be opened by pressing the F1 key, which will display help relating to the contents of the front window.

 The Help file is a hypertext document.  Clicking on a highlighted word displays information on that subect.  You can also click the search button in the Help program to search for a particular keyword.

The Using Help command provides details on relating to the use of the Help program.


Using Help

Using Help brings up a window providing general directions and suggestions for using the Help program.  The Help file for this program can be directly accessed with the Help Index command or by pressing the F1 key, which brings up help specific to what is shown in the front window.


About REFPROP

REFPROP is an acronym for REFrigerant  PROPerties.  This program, developed by the National Institute of Standards and Technology (NIST),  provides tables and plots of the thermodynamic and transport properties of pure refrigerants and refrigerant mixtures.

REFPROP is based on the most accurate pure fluid and mixture models currently available.  It implements three models for the thermodynamic properties of pure fluids:  the modified Benedict-Webb-Rubin equation of state, the Helmholtz-energy equation of state, and an extended corresponding state (ECS) model.  Mixture calculations employ a new model, which applies mixing rules to the Helmholtz energy of the mixture components; it uses a departure function to account for the departure from ideal mixing.  Viscosity and thermal conductivity are modeled with either  fluid-specific correlations or a new variation of the ECS method.

The property formulations were programmed by:

M.O. McLinden and E.W. Lemmon

Physical and Chemical Properties Division

National Institute of Standards and Technology

Boulder, CO 80303

The user interface was written by:

S.A. Klein

Mechanical Engineering Department

University of Wisconsin - Madison

Madison, WI 5370

A.P. Peskin

Physical and Chemical Properties Division

National Institute of Standards and Technology

Boulder, CO 80303

Development of this software package was supported by the Air-Conditioning and Refrigeration Technology Institute, the U.S. Department of Energy, the NIST Physical and Chemical Properties Division and the NIST Standard Reference Data Program. The development of the models on which this package is based and the measurement of the data on which the models are based have been supported over a period of many years by numerous sponsors including the Air-Conditioning and Refrigeration Technology Institute, the U.S. Department of Energy, the Electric Power Research Institute, the Environmental Protection Agency, Oak Ridge National Laboratory, the American Society of Heating Refrigerating and Air-Conditioning Engineers, the NIST Building Environment Division, and the NIST Physical and Chemical Properties Division and its predecessor, the Thermophysics Division.

The stay of S.A. Klein at NIST was funded, in part, by University of Wisconsin and by a grant from the National Science Foundation under Agreement No. 9527385. Any opinions, findings, and conclusions or recommendations expressed in this publication are those of the authors and do not necessarily reflect the views of the National Science Foundation.


Status Line

The Status line is displayed at the bottom of the screen.  The following information  is displayed in the status bar reflecting the current settings.

Fluid name

Fluid component(s)

Mixture mole or mass fractions

Reference state

If the settings used to determine the tabular values in the foremost window differ from the current settings, a second set of the information above is displayed showing the setting in the foremost window.

The fluid name may or may not differ from the name(s) of the fluid component(s).  A trade name or shortened name is often used, particularly for mixtures.

The components and compositions of a mixture are shown to the right of the fluid name.  If Molar basis is selected in the Units dialog, the molar composition is displayed as a decimal fraction.  If Mass basis is selected, the mass composition is displayed in percent.

 The reference state for enthalpy and entropy values which is selected with the Reference command is shown last.

Clicking the mouse button on the Status bar brings up either the Pure Fluid Information window or the Mixture Information window, as appropriate.