PhysPack User Guide
PhysPack
User Guide
PhysPack User Guide
NOTICE
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TRADEMARKS
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Corporation in the United States and/or other countries. All other trademarks are the property of
their respective owners.
COPYRIGHT
Copyright © 2001-2012 ABB Limited. All Rights Reserved.
Document:
Revision:
Published:
PhysPack User Guide
1.1
October 2012
Software:
Version:
PhysPack
4.2.0
SUPPORT INFORMATION
This program is developed, maintained and supported by PEL Support Services, ABB. We run a
Hotline telephone and email service to answer any queries about PhysPack.
Please let us have any suggestions on how you feel we could improve PhysPack. You can contact
us by any of the following routes:
ii
By Telephone:
+44 (0)1925 74 1126
By Fax:
+44 (0)1925 74 1265
By email:
[email protected]
By Post:
PEL Support Services
ABB Limited.
Daresbury Park
Daresbury
Warrington
Cheshire WA4 4BT
United Kingdom.
Contents
Preface ........................................................................................................................ 1
About this guide ...................................................................................................... 1
Who should read this guide ............................................................................. 1
What is in this guide ........................................................................................ 1
How this guide is structured ............................................................................ 1
Conventions .................................................................................................... 2
Chapter 1 – Introduction ...................................................................................... 3
What’s new.............................................................................................................. 3
Overview of PEL ..................................................................................................... 4
Chapter 2 – Getting started ................................................................................ 5
Starting PhysPack ................................................................................................... 5
Quitting PhysPack ................................................................................................... 5
User interface .......................................................................................................... 6
User assistance....................................................................................................... 6
Online help ...................................................................................................... 6
Online documentation ..................................................................................... 7
PEL Support Services ..................................................................................... 7
Chapter 3 – PhysPack Quick Tour .................................................................. 9
Part 1 – Components and aqueous solutions ......................................................... 9
The first 30 seconds … ................................................................................... 9
The next 30 seconds … ................................................................................ 10
Part 2 – Mixtures ................................................................................................... 11
Chapter 4 – Simple calculations..................................................................... 15
Calculating a pure component .............................................................................. 15
Selecting a pure component ......................................................................... 15
Viewing constant properties .......................................................................... 16
Viewing the calculated results ....................................................................... 17
Calculating an aqueous solution ........................................................................... 18
Selecting an aqueous solution ...................................................................... 18
Viewing constant properties .......................................................................... 19
Viewing the calculated results ....................................................................... 19
Changing the properties in the calculation ............................................................ 20
Specifying conditions for the calculation ............................................................... 20
Specifying conditions for a pure component ................................................. 21
Specifying conditions for an aqueous solution .............................................. 23
Changing the units for the calculation ................................................................... 24
Selecting molar or mass units ....................................................................... 25
Creating your own set of units ....................................................................... 25
Chapter 5 – Handling simple results ............................................................ 27
Viewing results as a graph .................................................................................... 27
Viewing a graph of the results ....................................................................... 28
Viewing the current graph ............................................................................. 28
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PhysPack User Guide
Adding selected results to the current graph ................................................ 29
Removing selected results from the current graph ....................................... 29
Printing your results .............................................................................................. 30
Printing all the results .................................................................................... 30
Printing selected results ................................................................................ 31
Saving your results ............................................................................................... 32
Saving the results as an Excel worksheet..................................................... 32
Copying the results to the clipboard .............................................................. 32
Copying selected results to the clipboard ..................................................... 32
Saving constants data ........................................................................................... 32
Chapter 6 – Advanced calculations .............................................................. 35
Calculating a mixture ............................................................................................ 35
Specifying the VLE method ........................................................................... 37
Specifying the LLE method ........................................................................... 39
Specifying the SLE method ........................................................................... 39
Describing the model..................................................................................... 39
Saving the current stream ............................................................................. 39
Changing the properties in the calculation ............................................................ 40
Changing the units for the calculation ................................................................... 40
Specifying type and conditions for the calculation ................................................ 41
Specifying the type of calculation .................................................................. 41
Specifying a VL Equilibrium calculation ........................................................ 42
Specifying a Nonequilibrium calculation ........................................................ 46
Specifying a VL Phase Envelope calculation ................................................ 47
Specifying a Binary (non-equilibrium) calculation ......................................... 48
Specifying a Binary (VL Equilibrium) calculation ........................................... 49
Specifying a VLL Equilibrium calculation ...................................................... 51
Specifying an LL Equilibrium calculation ....................................................... 52
Specifying an SL Equilibrium calculation ...................................................... 53
Specifying a VL Mass Flux calculation .......................................................... 54
Viewing results for a mixture ................................................................................. 55
Showing phase data for a mixture ........................................................................ 56
Saving a phase as the feed stream ............................................................... 57
Selecting the key component for relative volatility ........................................ 57
Copying phase data .............................................................................................. 57
Copying the phase data to the clipboard ....................................................... 57
Copy selected phase data to the clipboard ................................................... 57
Saving all constants data ...................................................................................... 58
Calculation failures ................................................................................................ 58
Chapter 7 – Saving PhysPack data ............................................................... 59
Managing calculations files ................................................................................... 59
Saving a calculation file ................................................................................. 59
Opening a calculation file .............................................................................. 59
Managing physical properties files ........................................................................ 59
Saving a physical properties file .................................................................... 60
Opening a physical properties file ................................................................. 60
Quick reference ..................................................................................................... 61
Revision history .................................................................................................... 63
Glossary ................................................................................................................... 65
Index........................................................................................................................... 67
iv
Preface
Welcome to PhysPack, the tool for calculating and analysing the physical properties of
mixtures, pure components and aqueous solutions.
About this guide
This guide is designed to assist you in becoming quickly familiar with the capabilities
of PhysPack, its interface and how the program is used.
Who should read this guide
This guide is written for users of PhysPack to help you take full advantage of its
calculation tools. If you are new to this product, we recommend that you first read The
60 Second Guide to PhysPack (Parts 1 and 2).
The guide assumes you are familiar with the Windows operating system. If you are
new to Windows, you can find help, tutorials and support information by clicking
Start > Help and Support.
What is in this guide
The guide contains descriptions and step-by-step instructions for all the tasks involved
in using PhysPack.
How this guide is structured
The chapters are organised as follows:
1.
Introduction
Introduces the product, outlining the main
features.
2.
Getting started
Shows how to start PhysPack, introducing the
user interface for the application.
3.
PhysPack Quick Tour
Tutorial for a typical session using PhysPack,
emphasising the commonly used features.
4.
Simple calculations
Shows how to run simple calculations for
pure components and aqueous solutions.
5.
Handling simple results
Shows how to handle results for simple
calculations.
6.
Advanced calculations
Shows how to set up calculations for
mixtures.
7.
Saving PhysPack data
Shows how to save calculation and physical
properties data so that it can be used in other
PEL applications.
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PhysPack User Guide
The guide also includes a quick reference section and a glossary.
Conventions
The following typographical conventions are used in this guide:
Convention
Description
Bold
To help with procedures, items that you click, select, or view may appear
with the bold format (buttons, options, and window titles, for example).
Italic
Proper names (software products, for example) and titles appear in the
italic format.
Monospace
Represents any text that appears on the computer screen or text that you
should type. It is also used for filenames, functions, and examples.
Monospace
oblique
Represents variable text where you would type in a specific value.
>
2
The chevron indicates a menu option in a procedure. For example, click
File > Open, means “on the File menu, click Open.”
Chapter 1 – Introduction
PhysPack is an easy-to-use database of physical properties, combined with a powerful
calculation engine suitable for both expert and less experienced users. It simplifies
chemical process design by enabling you to generate physical property data,
investigate them, and then transfer them to other PEL applications
You can quickly and easily obtain a diverse range of information both numerically and
graphically for pure components, aqueous solutions, or mixtures, for both single phase
or multiphase equilibrium and across a full range of temperatures and pressures.
Calculations for pure components
For pure components, simply select any one of the 18,000 components on the PEL
physical properties databank and PhysPack will instantly display the constant
properties (critical temperature, dipole moment, etc.), together with the liquid, vapour,
and solid properties over a range of temperatures and pressures. You can tailor the
output to your own requirements by specifying different ranges and different units of
dimension.
Calculations for aqueous solutions
The same applies for aqueous solutions. Simply select the solution, enter the
concentration, and PhysPack will display the results in the same format as for pure
compounds above. Specify a range of concentrations and see the effect this has on
different properties over a range of temperatures.
Calculations for mixtures
Mixtures are where the power of PhysPack really comes to the fore. Select the
compounds and specify their composition in either mass or molar units - you can
choose whichever you prefer and PhysPack will automatically generate the others.
Next, you can either choose from over 50 state-of-the-art methods to model the vapour
liquid equilibrium or you can let PhysPack choose the most appropriate one for you
using the built-in wizard. Then it's on to the type of calculation you wish to perform.
There are dozens to choose from - phase envelopes, binary plots, isothermal,
isenthalpic, isentropic, isochoric flashes to name just a few. The results are displayed
in an easy-to-read spreadsheet complete with quality assurance data for each point
calculated and phase composition data for each of the components.
What’s new
This latest version of PhysPack (version 4.2.0) adds a new calculation type for
mixtures. The VL Mass Flux calculation lets you calculate the mass flux for an
isentropic nozzle flow based upon the calculation methods described in API Standard
520 Part 1. See “Specifying the type of calculation” on page 41.
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PhysPack User Guide
Overview of PEL
PEL is a collection of tools to enable process engineers to carry out their day-to-day
tasks more quickly and reliably. The software includes purpose built programs to
generate datasheets, perform engineering calculations of liquid and / or gas flow,
investigate physical properties and create fault tree diagrams. Designed by engineers
for engineers, the tools are intuitive and easy to use. They can be used to work out
every day calculations, for troubleshooting issues such as bottlenecks, or when making
plant modifications. This low cost solution will enable engineers to design processes
more quickly and reliably with up-to-date and permanently available design data.
Benefits
 Allows engineers to be more efficient and productive. With fewer manual
calculations to do, tasks are carried out quicker;
 Improves QA and standardises procedures, through everyone using same set of
data and calculations;
 Human errors in calculations are reduced;
 Improves production as bottlenecks can be identified quickly so a solution can be
sought;
 Allows operators to get the best out of their existing assets by carrying out
modifications rather than designing new ones.
4
Chapter 2 – Getting started
This chapter shows you how to start PhysPack and introduces the user interface for the
application.
Starting PhysPack
The most common way of starting PhysPack is from the Windows Start menu, but you
can also run it from a desktop shortcut.
To start PhysPack from the Start menu:
 Click Start > All Programs > PEL > PhysPack.
If using the classic Start menu or earlier versions of Windows, click Start >
Programs...
The PhysPack application opens.
Quitting PhysPack
To quit PhysPack:
 Do one of:
 On the File menu, click Exit.
 Click the Close (X) button.
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PhysPack User Guide
User interface
Once you have started PhysPack, you see the following, or similar, user interface.
The following main features are apparent:
Menu bar.
Shows the command menus for accessing various features of the
application.
Components tab.
Specifies the components to be examined. If you are modelling a
mixture, you specify its composition here.
Properties tab.
Units tab.
Specifies the properties to be calculated and displayed.
Specifies the units of measurement for the calculations.
Specification tab.
Specifies the type and conditions for the calculation.
User assistance
PhysPack has the following forms of user assistance:
 Online help
 Online documentation
 PEL Support Services
Online help
PhysPack has an integrated online help system, which provides clear reference
information and step-by-step instructions for tasks.
To open the help system:
 On the Help menu, click User Guide.
The help opens in a separate window.
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Chapter 2 – Getting started
Online documentation
Documentation is provided for PEL products on the website. The documents are
provided as PDF files for you to download and print. These include:
 60 second guides
 Online user guides
PEL Support Services
This program is developed, maintained and supported by PEL Support Services, ABB.
We run a Hotline telephone and email service to answer any queries about PhysPack.
Please let us have any suggestions on how you feel we could improve PhysPack. You
can contact us by any of the following routes:
By Telephone:
+44 (0)1925 74 1126
By Fax:
+44 (0)1925 74 1265
By email:
[email protected]
By Post:
PEL Support Services
ABB Limited.
Daresbury Park
Daresbury
Warrington
Cheshire WA4 4BT
United Kingdom.
7
Chapter 3 – PhysPack Quick Tour
This chapter provides tutorials to get you started with the application. The tutorial,
which is divided into two parts, is available separately in print form (or as a PDF file)
entitled 60 Second Guide.
Part 1 – Components and aqueous solutions
This short self-paced tutorial will show you how easy it is to use PhysPack and how
quickly you can calculate accurate physical properties.
The first 30 seconds …
Within 30 seconds from now you will have learned how to use PhysPack to access
physical property data for pure components – both the constant properties like critical
temperature, critical pressure and boiling point, and the liquid and vapour properties
over a range of pressures and temperatures. You will also have learnt how to display
the results graphically.
Okay, the clock starts now…
Starting PhysPack
1)
Click Start > All Programs > PEL > PhysPack.
The main PhysPack window appears. There are 4 tabs across the top of the
window; the Components tab is selected by default. On this tab there are 3
options – Pure Component, Aqueous Solution, and Mixture; Pure Component is
the default.
The first thing we need to do is to select a component.
2)
In the Search for Name box, type MET for methanol. All the components on the
databank beginning with MET are then listed below. Click Methanol and
PhysPack automatically switches to the Constants tab to display all the constant
properties for Methanol.
Next, let‟s view the liquid and vapour properties.
3)
Click the Liquid tab.
All the liquid properties for Methanol over the temperature range 0 – 60°C at
1bara are automatically displayed. Notice at the bottom of the screen the Quality
Assurance panel displaying the validity of each calculated point value. Move the
cursor into the different cells to see their associated QA values.
4)
Click the Vapour tab to view the vapour properties.
All the vapour properties for Methanol over the temperature range 70 – 100°C at
1 bara are automatically displayed again with their associated QA codes.
Notice that the liquid properties stopped at 60°C and the vapour ones started at
70°C.
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PhysPack User Guide
5)
Click the Constants tab to check the boiling point.
Finally, let‟s plot a graph of saturated liquid vapour pressure v temperature
6)
Click the Liquid tab. Scroll
across to the Liquid
Saturated Vapour Pressure
and then click the column
header to select that
column. Next right-click
and click Graph Selected
Results from the context
menu.
You should now see the
graph opposite…
7)
Click the close (X) button to close the graph window.
The next 30 seconds …
Okay this time we‟re going to look at aqueous solutions and plot a graph of liquid
density v temperature at different concentrations – again all within 30 seconds!
8)
Click the Components tab and select Aqueous Solution.
First, let‟s look at the properties of a 15% W/W solution of nitric acid?
9)
Enter 15 in the %W/W box and then click Nitric Acid from the list of available
solutions.
Again PhysPack automatically switches to the Constants tab to display the
constant properties. Notice PhysPack reports the 2 concentrations it has used for
the interpolation of the results determined by combination of Nitric Acid – 10%
and 20%.
10) Click the Liquid tab to view the liquid properties.
And that‟s it – well not quite. Remember we wanted to plot the liquid density at
different concentrations. So we need to go to the Specification tab and set the
concentration ranges for the calculation.
11) Click the Specification tab and then select Range under the concentration panel.
Set the Start to 10%W/W, the Finish to 20%W/W, and the Step to 5%W/W.
Now all we need to do is
recalculate the results and
plot the graph
12) Click the Liquid tab to
display the new results over
the concentration range and
then click the column
header for Density to select
that column. Next rightclick and click Graph
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Chapter 3 – PhysPack Quick Tour
Selected Results on the context menu.
You should now see the graph opposite…
13) Click the close (X) button to close the graph window.
That‟s it – and all within 60 seconds! Time now to try out Part 2 of the 60 Second
Guide to PhysPack and see how easy is it to do more complicated calculations
involving mixtures of components.
After you‟ve learned the basics it‟s time to read the rest of the PhysPack User Guide.
This will tell you more about all of the really useful features and options in the
program.
Part 2 – Mixtures
This short self-paced tutorial will show you how easy it is to use the new PhysPack
and how quickly you can calculate accurate physical properties.
Within 60 seconds from now you will have learned how to use PhysPack and
produced a graph of the phase envelope for a mixture of methane, ethane and propane.
Okay, the clock starts now…
Starting PhysPack
1)
Click Start > All Programs > PEL > PhysPack.
The main PhysPack window appears. There are 4 tabs across the top of the
window; the Components tab is selected by default. On this tab there are 3
options – Pure Component, Aqueous Solution, and Mixture; Pure Component is
the default.
The first thing we need to do is add the components.
2)
Select the Mixture option.
A new panel is displayed with several tabs – the default one being Feeds. This tab
is where we select the components we are interested in and specify their
compositions.
3)
Click Add Component to display the Select Components from Databank
window.
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PhysPack User Guide
4)
In the Search for Name box, type ME for methane. All the components on the
databank beginning with ME are then listed below. Scroll down the list, Click
METHANE and then click Add to Stream at the bottom of the window to add
methane to our stream. (Tip: you can also double-Click the name to add it to the
list) Next, delete ME from the Search box and type ET for ethane; double-Click
ethane in the list to add ethane to the stream. Repeat this for propane. Finally,
click Close to return to the Mixture panel.
Next we need to set the feed for each component – 50% methane, 40% ethane,
10% propane by mass fraction
5)
Click the mass fraction column in the spreadsheet. Type 0.5 for methane, 0.4 for
ethane, and 0.1 for propane.
Notice that PhysPack automatically calculates the Mole, Mole Fraction, and
Mass.
Next, we need to check which method PhysPack has chosen to model the Vapour
Liquid Equilibrium.
6)
Click the VLE tab.
You can see that the Peng Robinson (PR/PR) method has been automatically
selected for both the vapour and the liquid phases. This method is an Equation-ofState and is very suitable for modelling hydrocarbons at high temperatures and
pressures. To find out more about VLE methods Click PhysProps Help on the
Help menu at the top of the screen. Then select Thermodynamic Models from the
Reference Guide.
Now on to specify the calculation type - we want a phase envelope calculation
7)
Click the Specification tab at the top of the screen. Click the down-arrow on the
box for selecting the calculation type and select VL Phase Envelope.
That‟s all we need to specify. We‟re now ready to do the calculation and see the
results so …
8)
Click the Stream tab at the top of the screen. After a few seconds PhysPack
presents the results in a spreadsheet. Move up and down using the scroll bar to
see the results and notice the Comments column which identifies the Maximum
Temperature, Maximum Pressure, and the Critical Point.
Fine, but we wanted a graph not a table so …
9)
Click the column header for Stream Pressure; the column goes black to show it
has been selected. Now right-click the column and click Graph Selected
Results in the context menu. Hey Presto! - there‟s your graph just like the one on
the previous page. If you right-click the graph you can modify its appearance to
your heart‟s content as well as print it or copy it to another program. Finally, click
the X at the top right hand corner of the Graph window to return to the
spreadsheet.
Now let‟s go back and see what happens if we use a different VLE method?
10) Click the Components tab at the top of the screen. Clear the Allow automatic
selection of VLE Method check box then select the Redlich Kwong Soave
method called RKS(API)/RKS(API) in the list.
11) Switch back the Stream tab. Select the Stream Pressure column, right-mouse
click, and select Add Selected Results to the Current Graph on the context
menu. Both sets of results appear on the same graph so you can easily compare
the differences between the two methods.
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Chapter 3 – PhysPack Quick Tour
And that‟s it. How‟s the time doing? Did you beat the clock? If you have, try
clicking on the Units tab and converting the Temperature from K to C and see
how easily different units can be used.
Now you‟ve learned the basics it‟s time to read the PhysPack User Guide. This will
tell you more about all of the really useful features and options in the program.
13
Chapter 4 – Simple calculations
PhysPack lets you run physical properties calculations for pure components, aqueous
solutions or mixtures.
This chapter shows you how to run simple calculations for pure components and
aqueous solutions, how to change the properties included in the results, how to specify
the conditions, such as temperature and pressure ranges, and how to change the units
for the results.
Calculating a pure component
The process for running a PhysPack calculation for a pure component is very easy to
follow. The starting point is the Components tab with the Pure Component option
selected. This is the default view of the application when you start PhysPack.
Selecting a pure component
The first step in running a calculation is to select the component. The default (Pure
Component) option lets you select a single component (chemical compound) for using
in your calculation. Components can be selected from any of the physical properties
databanks. The PPDS databank is the most comprehensive: the other options are for
specific applications, such as petroleum distillation.
To select a pure component:
1)
On the Components tab, click Pure Component. This is selected by default.
2)
In the Search for Name text box enter part of the component name as a search
string. You can include a wildcard (*) to
3)
In the Select Databank list, select which databank to search. The PPDS system is
selected by default.
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PhysPack User Guide
Components matching the search string appear in the Search Results list.
4)
Scroll down the list as necessary and click the component you want.
PhysPack automatically switches to the Constants tab to display all the constant
properties for the component. See “Viewing constant properties” on page 16.
Viewing constant properties
As soon as you select a component the Constants tab appears. This shows constant
property values for the component. These include values such as the component‟s
various names, its boiling and melting points and its standard state.
The drop-down list at the top of the dialog lets you switch between components in a
mixture. For a single pure component only one item is in the list.
Notice that further tabs have appeared – typically Liquid and Vapour. These contain
the calculated results for each of the phases.
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Chapter 4 – Simple calculations
Viewing the calculated results
Physical properties for the single component are calculated for both liquid and vapour
phases over a range of temperatures and pressures. The calculated results appear in a
separate tab for each phase. In each phase the results show the physical properties
calculated at various temperatures and pressures. The first two columns define the
temperature and pressure ranges: the remaining column show the property values at
each temperature and pressure.
By default, the properties are calculated for temperatures between 0 and 100°C in
steps of 10° at a pressure of 1 bar. This can be changed on the Specification tab. For
more information, see “Changing the properties in the calculation” on page 20.
Also by default, only the Liquid and Vapour phases are modelled. You can extend this
by clearing a check box on the Specification tab. For information on this, see “Using
VLE modelling” on page 22.
To view the results:
 Click the Liquid (or Vapour) tab.
Viewing quality assurance indicators
The bottom area of the tab shows various quality assurance indicators.
If you click any individual field, the four indicators show:
Validity. The validity of the calculation with respect to temperature.
Accuracy. The accuracy of the value, such as “< 1%”.
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PhysPack User Guide
Evaluation. The calculation method used, .such as “PPDS databank” or “Lee-Kesler
correction”.
Source. How the value was derived, such as. “Experimental” or “Calculated”.
Calculating an aqueous solution
The process for running a PhysPack calculation for an aqueous solution is similar to
the default pure component calculation.
Selecting an aqueous solution
This option lets you select an aqueous solution for your calculation.
To select an aqueous solution:
1)
On the Components tab, click Aqueous Solution.
2)
In the %W/W field, enter the concentration of the solution.
3)
Scroll down the Aqueous Components list as necessary and click the
component you want.
4)
The Constants tab.
PhysPack opens the Constants tab to show the constant properties for the
aqueous component. See “Viewing constant properties” on page 19.
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Chapter 4 – Simple calculations
Viewing constant properties
As soon as you select an aqueous component the Constants tab appears. This shows
constant property values for the aqueous component. This much smaller list includes
values such as minimum and maximum concentrations and boiling and melting points.
Notice that a single further tab has appeared – for Liquid phase results.
Viewing the calculated results
The calculated results for an aqueous solution appear in a single liquid phase tab. The
vapour and solid phases are not modelled. The results show the physical properties at
various concentrations and temperatures. The first two columns define the
concentrations and temperature ranges: the remaining column show the property
values.
By default, the properties are calculated for temperatures between 0 and 100°C in
steps of 10° at the concentration entered on the Components tab.
To view the results:
 Click the Liquid tab.
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PhysPack User Guide
Changing the properties in the calculation
PhysPack contains a large number of properties that can be included in a calculation.
By default, all the properties are calculated. The Properties tab lets you limit which
physical properties are included.
For pure components this covers the three phases – liquid, vapour and solid. For
Aqueous solutions, only a single set of properties appears.
By default all the properties in each phase are selected. You can also compile your
own set of properties by selecting and/or clearing items from the selection as follows:
 Click All to select all the properties for the phase
 Click None to clear the selection
 Drag though the list to select a group of properties
 Ctrl+click to select or clear individual properties
 Shift+click to select all the properties between the current and last selected items.
If you want to include most of the properties in your calculations, click All and
then use Ctrl+click to clear the individual properties you don‟t want.
Tip
Specifying conditions for the calculation
When you select a pure component or aqueous solution on the Component tab, results
are calculated automatically using the default conditions. The Specification tab lets
you specify new conditions, with results recalculated when you click a results tab.
The conditions for a calculation consist of two independent variables. These equate to
the first two columns in the results tables. Each variable can be specifed as either a list
(of one or more values) or a range of values. A range is delimited by start and finish
values, with the intermediate values set either by step size or by the number of points.
Each variable can have one or more values. If each variable has a single value the
physical properties are calculated for a single point (that is, the results tabs contains
20
Chapter 4 – Simple calculations
just one row). If each variable has mutiple values, the number of points is the product
of the numbers of each variable.
Specifying conditions for a pure component
For a pure component calculation the independent variables are temperature and
pressure: either can be first. By default both variables are defined as a range.
To change the order of the variables:
 In one of the variable list boxes, click the other option in the list.
The variables swap sides with all their underlying conditions.
To change the range of a variable:
1)
Enter new start and finish values as required.
If the start value is greater than the finish value the results appear in descending
order.
2)
Do one of:
 Enter a new step value
 Click No of Points and enter a new value. Then click Step to see the value
as a step difference.
To specify a variable as a list:
1)
Click the List option.
The section changes to a single list pane.
2)
Type the remaining values as required.
Using the condition variables in pairs
Usually if you specify multiple values for the two condition variables, the number of
points (and hence the number of rows in the results tabs) is a product of the two. If the
two variables have an equal number of (mutiple) values, PhysPack lets you consider
them as pairs. So, for example, if you have 11 values for pressure and 11 for
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PhysPack User Guide
temperature, your results can either have 121 rows (if the values are not paired) or 11
if they are.
To use condition values in pairs:
1)
For each variable, arrange the values (in either Range or List format) so that the
number of points is equal.
2)
A check box appears at the bottom of the tab.
3)
Select the Use Condition values in pairs check box.
The results are calculated for the condition values as pairs.
To use all condition value combinations:
 Clear the Use Condition values in pairs check box.
The results are recalculated with every combination of the condition values.
Using VLE modelling
By default, calculations for a pure component use VLE modelling. This assumes the
component can only exist in its liquid or vapour phase and so results are only
calculated for those two phases.
To model the component in all three phases:
 Clear the Use VLE check box.
An extra Solid phase tab appears.
To use VLE modelling for the component:
 Select the Use VLE check box.
The Solid phase tab disappears.
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Chapter 4 – Simple calculations
Specifying conditions for an aqueous solution
For an aqueous solution calculation the independent variables are concentration and
temperature: either can be first. By default, the concentration is defined as a list and
temperature as a range.
You can change the order of the variables, and you can change the range and specify
the number of points in each variable. If both variables have the same number of
points, an extra option lets you consider them in pairs. See “Using the condition
variables in pairs” on page 21.
To specify the calculation:
1)
Specify the order and range/list of the variables as required. See “Specifying
conditions for a pure component” on page 21.
2)
Click the Liquid tab to see the recalculated results.
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PhysPack User Guide
Changing the units for the calculation
The Units tab lets you select the units for values that appear on the Constants, the
Specification and the results tabs. Three predefined set of units are provided:
 Engineering units – the units most commonly used in the chemical process
industries. They are mostly SI units, but with a few variants, such as
Parameter
SI unit
Engineering unit
Temperature
K
C (Celcius)
Pressure
N/m2
bar
Dynamic viscosity
N.s/m2
cP
(Kelvin)
(centipoise)
Other units differ just by degree, such as mm for short length (instead of m).
 SI units – the international system of units, the standard metric system
 British units – standard UK (Imperial) or US units
Engineering units are the default set when you install PhysPack.You can set one of the
other predefined sets as the default or compile your own set.
To change the units to a predefined set:
1)
Click the Units tab.
2)
Click the button for the set you want to use, such as SI.
A prompt asks you if you want to select these units as the default so that the set is
loaded next time you start PhysPack.
3)
Click Yes.
The selected set appears in the dialog.
24
Chapter 4 – Simple calculations
Selecting molar or mass units
The Units tab lets you determine how properties such as specific heat, density and
entropy and enthalpy appear on both the constants tab and on the results tabs. They
can be shown as either a mass or molar quantity. For example, in engineering units
density is either in kg/m3 (mass units) or kmol/m3 (molar units).
To show values in molar units:
 On the Units tab, click Select Molar Units.
The affected values change on the Constants tab and on the results tabs.
To show values in mass units:
 On the Units tab, click Select Mass Units.
The affected values change on the Constants tab and on the results tabs.
Creating your own set of units
The Units tab lets you compile your own set of units. You can save these changes to a
file and reload as you need. The units file is saved by default to the PEL/Apps folder
where PhysPack is installed. You can save the file elsewhere.
To create a new set of units:
1)
On the Units tab, click the unit you want to change to select the cell in the table.
2)
Right-click the cell and click one of the alternative units in the context menu.
3)
Repeat for other units as required to complete your set.
4)
Click Save units to file, enter a name for file (the default is UserUnits.uns),
browse to where you want to save the file (optional) and click Save.
To load an existing set of units:
1)
On the Units tab, click Get units from file.
2)
Browse to where the file is saved (if not the PEL/Apps folder) and click Open.
A prompt asks you if you want to select these units as the default so that the set is
loaded next time you start PhysPack.
3)
Click Yes.
The selected set appears in the dialog.
25
Chapter 5 – Handling simple results
The previous chapter, simple calculations” on page 15, showed you how to create
results for pure components or aqueous solutions, and then modify the results by
changing the properties, conditions and/or units. This chapter shows you the various
ways to handle these results – viewing selected results as a graph, printing the results
tables and saving the data as an Excel spreadsheet.
Viewing results as a graph
Once you have created the results for a pure component or an aqueous solution and
modified the results as necessary by changing the properties, conditions and/or units,
you can view a plot of one or more columns of the results as a graph.
The appearance of a graph will depend on the how many properties you select to
appear on the graph and the range of the condition variables. For example, using the
default settings for a pure component and selecting one component would open a
graph with a single plotted line.
You can select the columns for your graph in any of the following ways:
 Click the column header to select a single column
 Ctrl+click to select further columns
 Drag though the headers to select a group of columns
 Click then Shift+click to select a group of adjacent columns.
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PhysPack User Guide
Multiple value graphs
If you select more than one column of property values, the graph will show multiple
lines in different colours with a key shown below. You will also see multiple lines if
you change the conditions to show more than one point for the pressure variable.
Notice that multiple columns of values appear as separate lines: multiple pressures can
sometimes appear as a continuation of the same line.
Various commands on the context (right-click) menu let you print the graph or copy
the image to the clipboard, so that you can paste the image into a report. You can also
change the formatting of the axes, title and legends or even the chart type, if you wish.
Viewing a graph of the results
To view results as a graph:
1)
Select one or more columns.
2)
Do one of:
 On the Results menu click Graph Select Results.
 Right-click the table and click Graph.
The graph opens in a pop-up window.
Viewing the current graph
After you close a graph you can open it again (as long as you haven‟t created another
one)
To view the current graph:
 Do one of:
 On the Results menu click Display Current Graph.
 Right-click the table and click Display Current Graph.
The graph reopens in a pop-up window.
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Chapter 5 – Handling simple results
Adding selected results to the current graph
This feature lets you add extra column of property values to the graph. The extra
values will appear on the graph as one or more lines.
For pure components, you can use this feature to show a single property across
each of the phases.
Tip
To add selected results to the current graph:
1)
Switch to the required results tab, if applicable.
2)
Select the columns you want to add to the graph.
3)
Do one of:
 On the Results menu click Add Selected Results to Current Graph.
 Right-click the table and click Add Selected Results to Current Graph.
The redrawn graph opens in a pop-up window.
Removing selected results from the current graph
To remove selected results from the current graph:
1)
Switch to the required results tab, if applicable.
2)
Select the columns you want to remove from the graph.
3)
Do one of:
 On the Results menu click Remove Selected Results from Current
Graph.
 Right-click the table and click Remove Selected Results from Current
Graph.
The graph reopens in a pop-up window.
To print the graph:
1)
Right-click the graph background and click Print.
The Print dialog opens.
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PhysPack User Guide
2)
The Print Setup tab lets you select a printer. Your default is already selected.
Click the tab to select a different printer.
3)
The Page Setup tab lets you fit the graph to the page and set margins. Click the
tab if you need to change the settings.
4)
On the Print tab, change the layout option, if required, and click Print.
Printing your results
This feature lets you print the table of results on the current results tab, or a selection
of rows from the table, to your local or network printer.
You can select the rows for printing in any of the following ways:
 Click a cell in the first two columns to select a single row
 Ctrl+click to select further rows
 Drag though the first two columns to select a group of rows
 Click then Shift+click to select a group of adjacent rows.
Printing all the results
This will print the table of results on the current tab.
To print all the results:
1)
Do one of:
 On the Results menu click Print Results as a Table > Print All Results.
 Right-click the table and click Print Results as a Table > Print All Resuts.
The Page Setup dialog opens.
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Chapter 5 – Handling simple results
2)
The dialog lets you fit the table onto one or more pages, set the margins and the
various print options. Change as required and then click OK.
3)
Choose your printer and click OK.
The results are sent to the printer.
Printing selected results
To print selected results:
1)
Select the rows you want to print.
2)
Do one of:
 On the Results menu click Print Results as a Table > Print Selected
Results.
 Right-click the table and click Print Results as a Table > Print Selected
Resuts.
The Page Setup dialog opens.
3)
Change the various options as required and then click OK.
4)
Choose your printer and click OK.
The results are sent to the printer.
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PhysPack User Guide
Saving your results
These features let you save the table of results on the current tab to a Microsoft Excel
file. You can also copy the results table, or a selection from the table, to the clipboard.
Saving the results as an Excel worksheet
To save the results as an Excel worksheet:
1)
Do one of:
 On the Results menu click Save Results as an Excel Worksheet.
 Right-click the table and click Save Results as an Excel Worksheet.
2)
Browse to where you want to save the file, rename the file if required and then
click Save.
Copying the results to the clipboard
To copy the results to the clipboard:
 Do one of:
 On the Results menu click Copy Results to Clipboard.
 Right-click the table and click Copy Results to Clipboard.
The whole table, including the column headers is copied to the clipboard as a tab
separated list. You can then paste the list into a Windows application.
Copying selected results to the clipboard
To copy the results to the clipboard:
1)
Select the required rows, columns or cells you want to copy.
2)
Do one of:
 On the Results menu click Copy.
 Right-click the table and click Copy.
 Press Ctrl+C.
The selected values (without column headers) are copied to the clipboard as a tab
separated list. You can then paste the list into a Windows application.
Saving constants data
This feature lets you save the data on the Constants tab as a report file. The file is in
plain text format.
To save the constants data to a report:
32
1)
Click the Constants tab
2)
On the Results menu click Save report for current component.
Chapter 5 – Handling simple results
3)
Browse to where you want to save the file, rename the file if required and then
click Save.
The data on the constants tab is saved as a plain text report file (.rep).
You can open the saved report file in any Windows application that handles text files,
such as Notepad.
Tip
If you want to print the file set the page orientation to “Landscape”.
33
Chapter 6 – Advanced calculations
The chapter on simple calculations covers the basic features of PhysPack in creating
calculations for pure components and aqueous solutions. This chapter shows you how
to set up physical properties calculations for mixtures.
Calculating a mixture
This option opens a multiple tab that lets you define a mixture for using in your
calculation. The Feeds tab lets you define the composition of the mixture. Further
tabs let you define the thermodynamic models used for defining vapour-liquid
equilibrium (for a liquid/gas two phase fluid), liquid-liquid equilibrium (for a twoliquid mixture) and solid-liquid equilibrium.
The Feeds tab provides a stream composition worksheet, which lets you define a
name and the constituent parts of the process stream. Whenever you open the dialog
the table always contains the last values used. This lets you run multiple calculations
on the same fluid without having to specify or load the stream each time.
You can add components to the stream and then specify the molar and/or mass
quantities in the stream.
To define a mixture:
1)
On the Components tab, click Mixture.
2)
In the Stream name field, enter a name for the stream.
3)
Add the various components, as described in “Adding Components” on page 36.
As soon as you add the first component, the Constants tab, a Streams tab and
the phase results tabs open in the background.
The molecular weight of each component and the average molecular weight for
the stream appear in the Mol Wt column on the worksheet.
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PhysPack User Guide
If you want to remove a component from the worksheet, click the component
name to select the whole row, right-click the row and click Remove Selected
Components.
4)
Specify the quantities or relative amounts of each component in one of the other
four columns:
 Molar – the molar quantity of each component.
 Mol Fraction –the mole fraction of each component.
 Mass – the mass of each component
 Mass Fraction – the mass fraction of each component
The worksheet calculates the values in the other three columns and the totals. If
you enter fraction values, you must ensure that they total to 1.
If you need to restart the calculation, right-click the worksheet and click Zero All
Cells.
5)
Click OK.
To clear all components:
 On the Feeds tab, click Clear Worksheet.
All of the components are removed from the table.
Adding Components
To add a component:
1)
On the Feeds tab, click Add Component.
The Select Components dialog opens.
2)
Click the Databank in the list and start typing a search string.
Matching entries appear in the Search Results pane as you type.
36
3)
Select the component you want and click Add to Stream.
4)
Add all the components you want and then click Close.
Chapter 6 – Advanced calculations
Specifying the VLE method
The VLE tab lets you specify the thermodynamic model used to calculate the vapourliquid equilibrium and the physical properties of the stream.
VLE Method.
You can either select the method in the list, or let the program choose
based on the components in the stream. The chosen method is used to evaluate the
phase equilibrium, i.e. the number of phases, the phase split and the equilibrium
compositions of the individual components.
Select „Accurate‟ or „Consistent‟ as the method for calculating
each of these groups of properties.
Calculation Mode.
In Consistent mode, the thermodynamic model is used to evaluate the properties.
This gives a consistent approach, but the results for some properties may be
significantly in error, e.g. 20-30% in liquid density values. Note that only certain
properties can be evaluated from the model. Fugacity, density, compressibility,
enthalpy, entropy and Gibbs free energy are evaluated in this manner. Other
properties such as heat capacity, viscosity and thermal conductivity are evaluated from
the databank methods irrespective of the accurate/consistent setting.
In Accurate mode, the properties are evaluated where possible from the stored
coefficients in the pure component databank. For the vapour phase, the Lee-Kesler
method is used for pressure corrections.
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PhysPack User Guide
Binary Interaction Parameters (BIPs)
Some thermodynamic VLE models can account for interactions between components
in the mixture which cause deviations from ideal behaviour. If such a model is used,
you can view and change the BIPs.
The spreadsheet shows which pair of components is being considered. In some cases
the Component 1 – Component 2 interaction parameter is the same as the Component
2 – Component 1 interaction parameter (symmetric) so only one cell for the pairing is
active. In the example above, the parameters are different (asymmetric).
Row / Col.
Identifies the first and second components being considered.
Vapour / Liquid. Identifies which phase and thermodynamic model is being
considered.
A / Alpha. Shows and lets you edit the temperature dependent coefficients for the
BIP A or Alpha value.
P/T. Shows and lets you edit the Lower, Reference and Upper pressure and
temperature values for the BIPs.
Source. Shows and lets you edit a string identifying the source for the BIP data.
Equation Code. Shows and lets you edit a numeric value (0, 1, 2) which specifies
the order of the temperature dependence of the BIP parameter, e.g.
0:
A = a0
1:
A = a0 + a1T
2:
A = a0 + a1T + a2T2
Reference. Shows and lets you edit a numeric code identifying a reference code for
the BIP data.
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Chapter 6 – Advanced calculations
Specifying the LLE method
The LLE tab lets you specify the thermodynamic model used to calculate the liquidliquid equilibrium of the stream.
LLE Method.
You can select the method in the list.
For information on choosing an equilibrium method, click Help > PhysProps Help to
browse the PPDS Reference Guide.
Specifying the SLE method
The SLE tab lets you specify the thermodynamic model used to calculate the solidliquid equilibrium of the stream.
SLE Method.
You can select the method in the list.
For information on choosing an equilibrium method, click Help > PhysProps Help to
browse the PPDS Reference Guide.
Describing the model
The Remarks tab lets you enter a description of the stream being modelled.
The information is entered as plain text.
Saving the current stream
The Files tab lets you save the current stream on the Feeds tab as a file or recall a
previously saved stream file. The saved file (.psm) contains the components and the
calculated molar/mass quantities, fractions and totals.
To save the current stream:
1)
Click the Files tab.
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PhysPack User Guide
2)
Click Save.
3)
Change the file name and location, if required, and click Save.
To open a saved stream:
1)
Click the Files tab.
2)
Click Open.
3)
Browse to select the stream file and click Open.
The recalled stream now appears on the Feeds tab.
Changing the properties in the calculation
As with simple calculations, the Properties tab lets you limit which physical
properties are included in the calculation. For a mixture this covers the three phases –
liquid, vapour and solid – the same as for pure components.
By default all the properties in each phase are selected. You can also compile your
own set of properties by selecting and/or clearing items from the selection as follows:
 Click All to select all the properties for the phase
 Click None to clear the selection
 Drag though the list to select a group of properties
 Ctrl+click to select or clear individual properties
 Shift+click to select all the properties between the current and last selected items.
Changing the units for the calculation
The Units tab lets you select the units for values that appear on the Constants, the
Specification and the results tabs. This is the same as for simple calculations. See
“Changing the units for the calculation” on page 24.
40
Chapter 6 – Advanced calculations
Specifying type and conditions for the calculation
For simple calculations the variables on the the Specification tab were restricted to
particular options – temperature and pressure (for pure components) or concentration
and temperature (aqueous solutions). For pure components, you could also change the
type of calculation by switching VLE modelling on or off.
For a mixture, you can select from a number of different calculation types. A wider
selection of conditions is provided which is dependent on the calculation type.
Specifying the type of calculation
Nonequilibrium. Calculates mixture properties but with no phase equilibrium.
The same composition is used for both phases, and no stream properties are
calculated.
VL Equilibrium. Calculates the vapour-liquid phase equilibrium first, i.e. the
quantity and composition of both phases, and then calculates properties for each phase
and the stream as a whole.
This is the most common type of calculation.
VL Phase Envelope.
two phase region.
Calculates the boundaries (temperature and pressure) of the
Binary (Nonequilibrium). Calculates binary mixture properties for a range of
compositions.
Binary (VL Equilibrium). Calculates the binary x-y diagram for two components
with phase equilibrium.
VLL Equilibrium. Calculates the vapour-liquid-liquid phase equilibrium first, i.e. the
quantity and composition of three phases, and then calculates properties for each
phase and the stream as a whole.
LL Equilibrium. Calculates the liquid-liquid phase equilibrium first, i.e. the
quantity and composition of both phases, and then calculates properties for each phase
and the stream as a whole.
SL Equilibrium. Calculates the solid-liquid phase equilibrium first, i.e. the quantity
and composition of both phases, and then calculates properties for each phase and the
stream as a whole.
VL Mass Flux. Calculates the mass flux (as per API 520) for isentropic nozzle flow,
i.e. for a specified inlet temperature and pressure, calculates the properties for
isentropic change to a series of lower pressures.
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PhysPack User Guide
Specifying a VL Equilibrium calculation
This type of calculation calculates the vapour-liquid phase equilibrium first, i.e. the
quantity and composition of both phases, and then calculates properties for each phase
and the stream as a whole. This is the most common type of calculation.
For this calculation type, you can select each of the independent variables from a list
of options. Some options, such as temperature and pressure, appear in each list: others,
such as bubble point are only available in one list. The options are:
First variable
Second variable
Pressure / Temperature
Temperature /, Pressure
Enthalpy
Entropy
Molar Vapour Fraction
Mass Vapour Fraction
Specific Volume
Bubble Point (i.e. Vapour Fraction = 0)
Dew Point (i.e. Vapour Fraction = 1)
Enthalpy / Entropy
Temperature
Pressure
Entropy / Enthalpy
Internal Energy
Specific Volume
Specific Volume
Temperature
Pressure
Internal Energy
The program does not let you select the same variable in both lists.
To specify the calculation:
1)
In the list of calculation types, click VL Equilibrium. This is set by default.
2)
Select each of the two variables in turn.
The options in the second list depend on your choice for the first variable.
3)
42
Specify a range for the variables or a list as required. See “Specifying conditions
for a pure component” on page 21.
Chapter 6 – Advanced calculations
4)
Click any of the results tabs to start calculating results for the stream as a whole,
or for the liquid or vapour phases.
Enthalpy / Entropy / Specific Volume calculations
In PPDS, Isenthalpic, Isentropic, and Isochoric calculations are always carried out in
„consistent‟ mode; that is, an isothermal (fixed pressure and temperature) calculation
is carried out iteratively until the specified enthalpy / entropy / volume is achieved,
using the thermodynamic model for the flash calculation to evaluate the appropriate
physical property.
If you have selected „accurate‟ calculation mode on the VLE tab of the stream builder,
then the final results are evaluated from the stored coefficients in the pure component
databank and this can mean that the calculated values are not at your specified points.
To overcome this, an Iterate check box appears until the variable list box. If you have
selected „consistent‟ mode, the check box does not appear.
If you select the check box, PhysPack will carry out the calculation iteratively until the
final calculated values are at the specified conditions.
Total amount
By default Enthalpy, Entropy and Volume values are in terms of the quantity of
material on either a mass or molar basis; for example enthalpy in kJ/kmol.
Alternatively, if you select the Use “Total” amount check box these values become
total quantities for the stream, with the units changing to kJ.
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PhysPack User Guide
Bubble point / dew point calculations
Within VL equilibrium calculation, you can calculate the bubble point or dew point at
varying pressures or temperatures.
To specify the calculation:
1)
In the list of calculation types, click VL Equilibrium.
2)
Select the first variable as Pressure or Temperature.
3)
Specify the range or list as required. See “Specifying conditions for a pure
component” on page 21.
4)
Select the second variable as Bubble Point (or Dew Point).
There are no parameters for the second variable.
5)
44
Click one of the results tabs. Bubble point (or dew point) appears as the first
result column.
Chapter 6 – Advanced calculations
Isenthalpic / Isentropic / Isochoric calculations
Modelling some processes is a two-stage calculation; for example, calculating the
temperature after an isenthalpic change from an initial temperature and pressure to a
new pressure requires you to calculate the enthalpy at the initial state, then calculate
the temperature at the new pressure at the same enthalpy. This feature lets you do this
as a single step.
To specify the calculation:
1)
In the list of calculation types, click VL Equilibrium.
2)
Select the two variables as Pressure and Temperature. This can be either way
around.
3)
Select the Isenthalpic / Isentropic / Isochoric check box.
The dialog changes to show 3 sections for upstream pressure, then upstream and
downstream temperature.
If the temperature variable is first, the sections are upstream temperature, then
upstream and downstream pressure.
4)
Select the type of calculation:
 Isenthalpic (constant enthalpy),
 Isentropic (constant entropy),
 Isochoric (constant specific volume).
5)
Specify range of the variables or list as required. See “Specifying conditions for a
pure component” on page 21.
6)
Click any of the results tabs to start calculating results for the stream as a whole,
or for the liquid or vapour phases.
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PhysPack User Guide
Specifying a Nonequilibrium calculation
This type of calculation calculates mixture properties but with no phase equilibrium.
The same composition is used for both phases, and no stream properties are
calculated.
As with a pure calculation, the independent variables are temperature and pressure:
either can be first. By default both variables are defined as a range.
You can change the order of the variables, and you can change the range and specify
the number of points in each variable. If both variables have the same number of
points, an extra option lets you consider them in pairs. See “Using the condition
variables in pairs” on page 21.
To specify the calculation:
46
1)
In the list of calculation types, click Nonequilibrium.
2)
Select the first variable as Pressure or Temperature.
3)
Specify the range or list for each variable as required. See “Specifying conditions
for a pure component” on page 21.
4)
Click either of the results tabs to start calculating results for the liquid and vapour
phases.
Chapter 6 – Advanced calculations
Specifying a VL Phase Envelope calculation
This type of calculation calculates the boundaries (temperature and pressure) of the
two phase region. It calculates the temperature and pressures at a specified vapour
fraction and temperature/pressure. It continues along the phase envelope at the same
vapour fraction to the critical point and then moves away from the critical point,
calculating for a vapour fraction equal to 1 minus the specified value.
The stream must contain at least two components before a phase envelope
calculation can be carried out.
Note
To specify the calculation:
1)
In the list of calculation types, click VL Phase Envelope.
2)
Do one of:
 Enter the start temperature.
 Click Start Pressure and enter the pressure.
3)
Enter the vapour fraction.
This is a value in the range 0.0 to 1.0 which specifies the mole fraction of the
stream in the vapour phase for the first part of the envelope. If this is zero then
the calculation follows the bubble line up to the critical point and then the dew
line moving away from the critical point. If the value is 1.0 then the calculation
is performed the other way round.
4)
Enter the number of points to calculate along the envelope.
This is the maximum number of points – the actual number may be smaller, and
in any case will not exceed 500.
5)
Click any of the results tabs to start calculating results for the stream as a whole,
or for the liquid or vapour phases.
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PhysPack User Guide
Specifying a Binary (non-equilibrium) calculation
This type of calculation calculates binary mixture properties for a range of
compositions.
The independent variables are temperature and pressure: either can be first. The first
variable can be either a range or a list of values: the second is a single fixed value.
An additional Binary Calculation section and the centre section let you specify the
starting and finishing fractions for the first binary component in the stream.
To specify the calculation:
48
1)
In the list of calculation types, click Binary (Nonequilibrium).
2)
Select the first variable as Pressure or Temperature.
3)
Specify the range or list of the first variable as required. See “Specifying
conditions for a pure component” on page 21.
4)
Enter a single fixed value for the second variable.
5)
In the Binary Calculation section, click the appropriate option to specify whether
the composition is based upon a Mole Fraction or a Mass Fraction.
6)
Also under Binary Calculation, specify which components in the mixture are to
be treated as the first and second components in a binary mixture. Any other
components in the original mixture are ignored.
7)
In the centre section, specify the starting and finishing fractions for the first
component. The defaults are from 0 to 1.
8)
Click either of the results tabs to start calculating results for the liquid and vapour
phases.
Chapter 6 – Advanced calculations
Specifying a Binary (VL Equilibrium) calculation
This type of calculation calculates the binary x-y diagram for two components with
phase equilibrium.
For this calculation type, you can select each of the independent variables from a list
of options. Some options, such as temperature and pressure, appear in each list: others,
such as bubble point are only available in one list. The options are:
First variable
Second variable
Pressure / Temperature
Temperature / Pressure
Enthalpy
Entropy
Molar Vapour Fraction
Mass Vapour Fraction
Specific Volume
Bubble Point
Dew Point
Enthalpy / Entropy
Temperature
Pressure
Entropy / Enthalpy
Internal Energy
Specific Volume
Specific Volume
Temperature
Pressure
Internal Energy
The program does not let you select the same variable in both lists. The first variable
can be either a range or a list of values: the second is a single fixed value.
An additional Binary Calculation section and the centre section let you specify the
starting and finishing fractions for the first binary component in the stream.
To specify the calculation:
1)
In the list of calculation types, click Binary (VL Equilibrium).
2)
Select the first variable and specify a range or list of values as required. See
“Specifying conditions for a pure component” on page 21.
3)
Enter a single fixed value for the second variable.
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PhysPack User Guide
You don‟t need to do this for Bubble Point or Dew Point.
50
4)
In the Binary Calculation section, click the appropriate option to specify whether
the composition is based upon a Mole Fraction or a Mass Fraction.
5)
Also under Binary Calculation, specify which components in the mixture are to
be treated as the first and second components in a binary mixture. Any other
components in the original mixture are ignored.
6)
Click any of the results tabs to start calculating results for the liquid and vapour
phases, and for the stream as a whole.
Chapter 6 – Advanced calculations
Specifying a VLL Equilibrium calculation
This type of calculation calculates the vapour-liquid-liquid phase equilibrium first –
that is, the quantity and composition of three phases – and then calculates properties
for each phase and the stream as a whole.
As with a pure calculation, the independent variables are temperature and pressure:
either can be first. By default both variables are defined as a range.
You can change the order of the variables, and you can change the range and specify
the number of points in each variable. If both variables have the same number of
points, an extra option lets you consider them in pairs. See “Using the condition
variables in pairs” on page 21.
To specify the calculation:
1)
In the list of calculation types, click VLL Equilibrium.
2)
Select the first variable as Pressure or Temperature.
3)
Specify a range for the variables or a list as required. See “Specifying conditions
for a pure component” on page 21.
4)
Click any of the results tabs to start calculating results for the vapour phase, the
two liquid phases, and the stream as a whole.
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PhysPack User Guide
Specifying an LL Equilibrium calculation
This type of calculation calculates the liquid-liquid phase equilibrium first, i.e. the
quantity and composition of both phases, and then calculates properties for each phase
and the stream as a whole.
As with a pure calculation, the independent variables are temperature and pressure:
either can be first. By default both variables are defined as a range.
You can change the order of the variables, and you can change the range and specify
the number of points in each variable. If both variables have the same number of
points, an extra option lets you consider them in pairs. See “Using the condition
variables in pairs” on page 21.
To specify the calculation:
52
1)
In the list of calculation types, click LL Equilibrium.
2)
Select the first variable as Pressure or Temperature.
3)
Specify a range for the variables or a list as required. See “Specifying conditions
for a pure component” on page 21.
4)
Click any of the results tabs to start calculating results for the two liquid phases
and for the stream as a whole.
Chapter 6 – Advanced calculations
Specifying an SL Equilibrium calculation
Calculates the solid-liquid phase equilibrium first, i.e. the quantity and composition of
both phases, and then calculates properties for each phase and the stream as a whole.
As with a pure calculation, the independent variables are temperature and pressure:
either can be first. By default both variables are defined as a range.
You can change the order of the variables, and you can change the range and specify
the number of points in each variable. If both variables have the same number of
points, an extra option lets you consider them in pairs. See “Using the condition
variables in pairs” on page 21.
To specify the calculation:
1)
In the list of calculation types, click SL Equilibrium.
2)
Select the first variable as Pressure or Temperature.
3)
Specify a range for the variables or a list as required. See “Specifying conditions
for a pure component” on page 21.
4)
Click any of the results tabs to start calculating results for the liquid and solid
phases, and for the stream as a whole.
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PhysPack User Guide
Specifying a VL Mass Flux calculation
Calculates the mass flux (as per API 520) for isentropic nozzle flow, i.e. for a
specified inlet temperature and pressure, calculates the properties for isentropic change
to a series of lower pressures.
The independent variables are the initial temperature and a series of pressures, the first
of which is considered the initial pressure. An isentropic flash calculation is carried
out from the inlet conditions to each of the specified pressures. By default, the
pressures are specified as a range. For each point, as well as the usual physical
properties, the maximum mass flux is calculated for isentropic flow (adiabatic and
reversible) through a nozzle from the inlet pressure to the specified downstream
pressure.
The method upon which this calculation is based is described in API Standard 520
Part 1, 8th edition (Dec 2008) (Annex C "Sizing for Two-phase Liquid/Vapor Relief",
Section C.2.1 "Sizing by Direct Integration of the Isentropic Nozzle Flow"). The
purpose is to identify the pressure at which the mass flux is a maximum: if greater
than the specified outlet pressure then this indicates choked flow in the nozzle.
To specify the calculation:
1)
In the list of calculation types, click VL Mass Flux.
2)
Specify the inlet temperature as the first variable
3)
Specify a range of values for the pressure as required. See “Specifying conditions
for a pure component” on page 21.
Typically the pressures will be in descending order, from the inlet pressure to the
outlet pressure.
4)
Click any of the results tabs to start calculating results for the stream as a whole
and the vapour and liquid phases.
On the stream results, the conditions at which the Stream Mass Flux is a maximum
can be determined. Selecting the Stream Mass Flux column allows the results to be
plotted as a graph. The results in the columns for Stream Pressure and Stream Density
can be copied and pasted into an external pressure relief calculation, e.g. the “2 Phase
Direct Integration” calculation in PEL CAPRE.
54
Chapter 6 – Advanced calculations
Viewing results for a mixture
For a mixture you can see a larger number of results tabs than for a simple calculation.
The number of tabs will depend on the nature of the mixture, the type of calculation
and the properties selected.
The following tabs may appear for mixtures:
Stream tab This shows the results for the stream as a whole: averaged over the
phases present. The tab is only available with one of the equilibrium calculations. The
properties shown are set by PhysPack and not determined by the Properties tab.
Liquid tab
This shows the results for the liquid phase.
Liquid2 tab This shows the results for the second liquid phase. The tab is only
available with a VLL Equilibrium or LL Equilibrium calculation.
Vapour tab This shows the results for the vapour phase. The tab is not available for
LL Equilibrium or SL Equilibrium calculations.
Solid phase tab This shows the results for the solid phase. The tab is only available
with an SL Equilibrium calculation.
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PhysPack User Guide
Showing phase data for a mixture
In addition to the various results tabs that show the calculated properties for the stream
and the different phases, you can view information about each of the phases that are
present in the stream. This feature is only available for mixtures.
In the stream results tab, the phase data has a tab for each of the phases present. In the
individual phase results tab, only the phase data for that tab appears. The information
about the phases in the stream includes a table (similar to the spreadsheet on the
stream builder) which shows:
 Molar and mass amounts (by component) for the phase
 Molar and mass fractions (by component) for the phase
 For a liquid phase, if the vapour phase is also present, two extra column show the
K Value and Relative Volatility for each component.
 Fraction of phase in stream – molar and mass
The bottom line of the window shows the total molar/mass fraction for the phase and
the molecular weight of the phase.
To view the phase data:
 Do one of:
 On the Results menu click Show Phase Data.
 Right-click the table and click Show Phase Data.
The Phase Data table appears in the lower half of the main window.
56
Chapter 6 – Advanced calculations
Saving a phase as the feed stream
From the phase data table you can use the composition of the phase as the feed stream.
To save phase as feed stream
 In the Phase Data table, right click and click Save Phase as Feed Stream.
The stream composition on the feeds tab of the Stream builder now matches the
chosen phase data.
Selecting the key component for relative volatility
The Relative Volatility values that can appear for a liquid phase are calculated relative
to the component in the mixture designated as the key component. By default this is
the first component added to the mixture, but you can change it.
The key component is shown on the context menu by a check mark.
To select a different key component:
 In the Phase Data table, right click and click the component you want..
Copying phase data
Just as you can copy results data to the clipboard, you can do the same for phase data.
Copying the phase data to the clipboard
To copy the phase data to the clipboard:
 Right-click the table and click Copy Phase Data to Clipboard.
The whole table, including the column headers is copied to the clipboard as a tab
separated list. You can then paste the list into a Windows application.
Copy selected phase data to the clipboard
Select the rows or selected cells and click Copy
To copy the phase data to the clipboard:
1)
Select the required rows, columns or cells you want to copy.
2)
Right-click the table and click Copy.
The selected values (without column headers) are copied to the clipboard as a tab
separated list. You can then paste the list into a Windows application.
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PhysPack User Guide
Saving all constants data
For a mixture you have a second command that is not available for single components.
This lets you save the constants data for all components in the mixture as a report file.
The file is in plain text format.
To save the constants data to a report:
1)
Click the Constants tab
2)
On the Results menu click Save report for all components.
3)
Browse to where you want to save the file, rename the file if required and then
click Save.
The data on the constants tab is saved as a plain text report file (.rep).
Calculation failures
The advanced calculations for a mixture and the various setting you can use can
sometimes result in a calculation error. This can often be caused by selecting the
wrongs equilibrium method for your selected components.
Any error messages appear in the Messages tab.
58
Chapter 7 – Saving PhysPack data
When you have started to utilise the full power of PhysPack to model complex
calculations for a mixture, you will want to save some details from the calculation to
avoid having to repeat the process.
This chapter shows you how to save (and reopen) the complete calculation and how to
save the physical properties data so that it can be used in other PEL applications.
Managing calculations files
A PhysPack calculation file (.physpack) stores all the information required to perform
a particular calculation: that is (1) the properties, specification and units settings and
(2) the physical properties information that defines the stream. The stream data can
either be embedded in the calculation file or saved as a separate file.
Saving a calculation file
To save a calculation file with embedded physical properties data:
1)
On the File menu, click Save Calculation File > Embed physprops data.
2)
Change the file name and location, if required, and click Save.
To save a calculation file with a linked physical properties file:
1)
On the File menu, click Save Calculation File > Link to physprops file.
You are first prompted to save the physical properties data.
2)
Change the file name and location, if required, and click Save.
You are then prompted to save the calculation data.
3)
Change the file name and location, if required, and click Save.
Opening a calculation file
To open a calculation file:
1)
On the File menu, click Open Calculation File.
2)
Navigate to select the file and click Open.
Managing physical properties files
The physical properties information for a stream, that is the components that define
the mixture and their relative amounts or fractions, can be saved as a separate file.
This lets you run multiple calculations using a common physical properties file.
Two file formats are supported for physical properties files:
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PhysPack User Guide
 .psm – a plain text file which allows PhysPack to look up components in the
databank to obtain their data.
 .pds – a binary file which contains all of the data for individual components, so
calculations will always yield the same results even if data in the databank is
updated.
Saving a physical properties file
To save a physical properties file:
1)
On the File menu, click Save PhysProps File.
2)
Change the file name and location, if required, and click Save.
Opening a physical properties file
To open a physical properties file:
1)
On the File menu, click Open PhysProps File.
2)
The default file type is the text format (.psm). To locate a binary format file, click
PDS format in the list of formats.
3)
Navigate to select the file and click Open.
The application switches to the Component tab showing the Feeds tab of the Stream
builder.
60
Quick reference
The following tables define the commands on the menu system.
File menu
Command
Action
See
Open Calculation File
Open an existing calculation file
(.physpack)
“Opening a calculation file”
on page 59
Save Calculation File
> Embed physprops
data
Save a calculation specification:
phys props data is saved within the
calculation file.
“Saving a calculation file”
on page 59
Save Calculation File
> Link to physprops
file
Save a calculation specification:
phys props data is saved in a
separate phys props file which is
named in the calculation file.
“Saving a calculation file”
on page 59
Open PhysProps File
Open a physical properties file
(.psm, .pds)
“Opening a physical
properties file” on page 60
Save PhysProps File
Save the specification of the current
stream in a physical properties file
(.psm, .pds)
“Saving a physical
properties file” on page 60
Exit
Quit PhysPack
“Quitting PhysPack” on
page 5
Results menu
The following options only appear when the calculation results tabs are open
Command
Action
See
Display Current
Graph
Show the current graph
“Viewing the current graph”
on page 28
Add Selected Results
to Current Graph
Add extra column of results to
current graph
“Adding selected results to
the current graph” on page
29
Remove Selected
Results from Current
Graph
Remove column of results from
current graph
“Removing Selected
Results from Current
Graph” on page 29
Graph Selected
Results
View results as a graph
“Viewing a graph of the
results” on page 28
Show Phase Data
Show/hide Phase data window
“Showing phase data for a
mixture” on page 56
Print Results as a
Table > Print All
Results
Print all the results on the current tab
“Printing all the results” on
page 30
Print Results as a
Table > Print
Selected Results
Print selected results on the current
tab
“Printing selected results”
on page 31
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PhysPack User Guide
Save Results as an
Excel Worksheet
Save the results as an Excel
worksheet
“Saving the results as an
Excel worksheet” on page
32
Copy Results to
Clipboard
Copy the results to the clipboard
“Copying the results to the
clipboard” on page 32
Copy
Copy selected results to the
clipboard
“Copying selected results
to the clipboard” on page
32
The following options only appear when the constants tab is open
Command
Action
See
Save report for
current component
Save the constants data for current
component as a report file
“Saving constants data” on
page 32
Save report for all
components
Save the constants data for all the
components as a report file (mixture
only)
“Saving all constants data”
on page 58
Command
Action
See
Help – User Guide
Open the online help version of the
PhysPack User Guide
Help – PhysProps
Open the online PPDS Reference
Guide
Check for updates
Not enabled in this version of the
software
About
Open the PhysPack splash screen
Help menu
62
Revision history
The following table records the revision history of this guide.
Revision
Date
Description of change
1.0
07 Sep 2012
Guide written for PEL release 19.5
1.1
19 Oct 2012
VL Mass Flux calculation added
.
63
Glossary
60 Second Guide
A short self-paced tutorial that takes you through the main features of a PEL
application.
API
American Petroleum Institute – U.S trade association for the oil and gas industry.
Provides over 500 operating standards for the industry, many of them adopted by ISO
as international standards.
BIP
Binary Interaction Parameters.
Bubble point
The temperature at which a liquid consisting of two or more components starts to
evaporate – the onset of the vapour phase. See also Dew point.
For a pure component the bubble point and dew point are the same and are referred to
as the boiling point.
CAPRE
(pronounced CAPR-i) stands for CAlculations for Pressure Relief in Excel. A new
addition to the PEL software range, it provides engineers with a suite of commonlyused pressure relief calculations within Excel.
CARN
Chemical Abstracts Registry Number. A scheme for uniquely identifying chemical
compounds. The code is in the form nnnnnn-nn-n.
Dew point
The temperature at which a vapour consisting of two or more components starts to
condense – the onset of the liquid phase.
Isenthalpic
A vapour-liquid phase equilibrium calculation defining either pressure or temperature
carried out at constant enthalpy.
65
PhysPack User Guide
Isentropic calculation
A vapour-liquid phase equilibrium calculation defining either pressure or temperature
carried out at constant entropy.
Isochoric calculation
A vapour-liquid phase equilibrium calculation defining either pressure or temperature
carried out at constant volume.
LLE
Liquid-Liquid Equilibrium.
Phase envelope
A phase envelope marks the boundaries of the temperature and pressure combinations
where a mixture can exist as vapour and liquid fractions.
The envelope consists of a dew point curve intersecting a bubble point curve at the
mixture's critical point. The Dew point curve indicates the temperature and pressure
when a vapour having its pressure increased and/or temperature decreased will first
form drops of liquid. Similarly the Bubble point curve indicates where the first bubble
of vapour appears when heating and/or de-pressurising a liquid.
PPDS
Physical Properties Data Service. A software suite used extensively in the chemical
production, oil & gas, pharmaceutical, fine chemical, power generation and process
industries. It allows users to perform calculations and simulations across a wide range
of process and engineering applications. PPDS facilities are included in PhysPack.
The software is maintained by NEL (formerly the National Engineering Laboratory),
part of the German-owned TÜV SÜD group.
SLE
Solid-Liquid Equilibrium.
SMILES
Simplified Molecular Input Line Entry System. A mechanism for representing
molecular structures as a string of alphanumeric characters.
Stream
Any distinct and separate body of fluid, containing one or more components.
VLE
Vapour-Liquid Equilibrium. A condition for a two-phase fluid, where the rate of
evaporation (liquid to vapour) is the same as the rate of condensation (vapour to
liquid).
66
Index
A
Adding Components 36
Adding selected results to the current graph 29
B
Binary Interaction Parameters (BIPs) 38
Bubble point / dew point calculations 44
C
Copy selected phase data to the clipboard 57
Copying selected results to the clipboard 32
Copying the phase data to the clipboard 57
Copying the results to the clipboard 32
Creating your own set of units 25
D
Describing the model 39
E
Enthalpy / Entropy / Specific Volume calculations 43
F
File menu 61
H
Help menu 62
I
Isenthalpic / Isentropic / Isochoric calculations 45
M
P
PEL Support Services 7
Printing all the results 30
Printing selected results 31
R
Removing selected results from the current graph 29
Results menu 61
S
Saving a calculation file 59
Saving a phase as the feed stream 57
Saving a physical properties file 60
Saving constants data 32
Saving the current stream 39
Saving the results as an Excel worksheet 32
Selecting a pure component 15
Selecting an aqueous solution 18
Selecting molar or mass units 25
Selecting the key component for relative volatility 57
Specifying a Binary (non-equilibrium) calculation 48
Specifying a Binary (VL Equilibrium) calculation 49
Specifying a Nonequilibrium calculation 46
Specifying a VL Equilibrium calculation 42
Specifying a VL Mass Flux calculation 54
Specifying a VL Phase Envelope calculation 47
Specifying a VLL Equilibrium calculation 51
Specifying an LL Equilibrium calculation 52
Specifying an SL Equilibrium calculation 53
Specifying conditions for a pure component 21
Specifying conditions for an aqueous solution 23
Specifying the LLE method 39
Specifying the SLE method 39
Specifying the type of calculation 41
Specifying the VLE method 37
Multiple value graphs 28
T
O
The first 30 seconds … 9
The next 30 seconds … 10
Online documentation 7
Online help 6
Opening a calculation file 59
Opening a physical properties file 60
U
Using the condition variables in pairs 21
Using VLE modelling 22
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PhysPack User Guide
V
Viewing a graph of the results 28
Viewing constant properties 16, 19
Viewing quality assurance indicators 17
Viewing the calculated results 17, 19
Viewing the current graph 28
68
ABB Limited
PEL Support Services
Daresbury Park, Daresbury,
Warrington, Cheshire, WA4 4BT
United Kingdom
Tel: +44 (0) 1925 741126
Fax: +44 (0) 1925 741265
Email: [email protected]
www.pelsoftware.com
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