1.2 Steady State Simulation
1.2.5 Using the Workbook
The Workbook displays information about streams and unit operations in a tabular format, while the PFD is a graphical representation of the flowsheet. Click the Workbook icon on the toolbar to access the Workbook property view.
Installing the Feed Streams
In general, the first action you perform when you enter the Simulation environment is installing one or more feed streams. The following procedure explains how to create a new stream using the workbook.
1. On the Material Streams tab of the Workbook, type the stream name Feed 1 in the cell labelled **New**, and press ENTER. (HYSYS accepts blank spaces within a stream or operation name.) HYSYS automatically creates the new stream with the name defined above.
Next you will define the feed conditions.
2. Move to the Temperature cell for Feed 1 by clicking it, or by pressing the DOWN arrow key.
3. Type 60 in the Temperature cell. In the Unit drop-down list, HYSYS displays the default units for temperature, in this case F. This is the correct unit for this exercise.
4. Press the ENTER key.
Your active location should now be the Pressure cell for Feed 1. If you know the stream pressure in another unit besides the default unit of psia, HYSYS will accept your input in any one of the available different units and automatically convert the supplied value to the default unit for you. For this example, the pressure of Feed 1 is 41.37 bar.
5. In the Pressure cell, type 41.37.
6. Click the icon in the Unit drop-down list to open the list of units, or press the SPACE BAR to move to the Units drop- down list.
7. Either scroll through the list to find bar, or begin typing it. HYSYS will match your input to locate the required unit.
8. Once bar is selected, press the ENTER key.
HYSYS will automatically convert the pressure to the default unit, psia, and the active selection moves to the Molar Flow cell for Feed 1.
9. In the Molar Flow cell, type 6 and press ENTER. The default Molar Flow unit is already MMSCFD, so you do not have to modify the units.
Providing Compositional Input
In the previous section you specified the stream conditions in the Workbook property view. Next you will input the composition information in the Stream property view.
1. Close the Workbook property view.
The PFD becomes visible and displays a light blue arrow on it, labeled Feed 1. That arrow is the stream Feed 1 that you just created
Double-click the blue arrow. The Feed 1 view appears.
2. Click on the Composition page. By default, the components are listed by Mole Fractions.
3. Click on the Mole Fractions cell for the first component,
Nitrogen.
4. Type 0.01 and press ENTER.
The Input Composition for Stream property view appears.
This property view lets you access certain features designed to streamline the specification of a stream composition and complete the stream’s compositional input.
Figure 1.10
The following table lists and describes the features available on the Input Composition for Stream property view:
5. Click on the Mole Fraction cell for CO2, type 0.01, then press ENTER.
Composition Input Feature Description
Composition Basis
Radio Buttons Allows you to input the stream composition in some fractional basis other than Mole Fraction, or by component flows, by selecting the appropriate radio button before providing your input.
Normalizing The Normalizing feature allows you to enter the relative ratios of components; for example, 2 parts N2, 2 parts CO2, 120 parts C1, etc. Rather than manually converting these ratios to fractions summing to one, enter the individual numbers of parts and click the Normalize button. HYSYS will compute the individual fractions to total 1.0. Normalizing is also useful when you have a stream consisting of only a few components. Instead of specifying zero fractions (or flows) for the other components, enter the fractions (or the actual flows) for the non-zero components, leaving the others <empty>. Click the Normalize button, and HYSYS will force the other component fractions to zero.
Calculation status/
colour As you input the composition, the component fractions (or flows) initially appear in red, indicating the final composition is unknown. These values will become blue when the composition has been calculated. Three scenarios will result in the stream composition being calculated:
• Input the fractions of all components, including any zero components, such that their total is exactly 1.0000. Then click the OK button.
• Input the fractions (totalling 1.000), flows or relative number of parts of all non-zero components. Click the Normalize button, then the OK button.
• Input the flows or relative number of parts of all components, including any zero
components, then click the OK button. The red and blue text are the default colours; yours may appear different depending on your settings on the Colours page of the Session Preferences property view.
6. Enter the remaining fractions as shown in the figure below.
When you have entered the fraction of each component the total at the bottom of the property view will equal 1.0000. 7. Click the OK button, and HYSYS accepts the composition.
The stream is now completely defined, so HYSYS flashes it at the conditions given to determine its remaining properties.
8. Close the Feed 1 property view and access the Workbook property view by clicking on the Workbook icon.
9. Ensure that the Material Streams tab is active.
Figure 1.12
The properties of Feed 1 appear below. The values you specified are blue and the calculated values are black.
Alternative Methods for Defining Streams
In addition to the method you just learned, there are several alternative ways to define streams.
1. Access the Object Palette by pressing F4. 2. Do any one of the following:
• Press F11.
• From the Flowsheet menu, select Add Stream. • Double-click the Material Stream icon on the Object
Palette.
• Click the Material Stream icon on the Object Palette, then click on the Add Object icon.
Each of the above four methods creates a new stream and access the property view of the new stream.
Figure 1.14
If you want to delete a stream, click on it in the PFD, then press the DELETE key. HYSYS will ask for confirmation before deleting.
You can also delete the stream using the Delete button on that stream’s property view.
Material Stream icon Add Object icon
The new stream is named according to the Automatic Naming of Flowsheet Objects setting defined in the Session Preferences (Simulation tab, Naming page). HYSYS names any new material streams with numbers starting at 1 and any new energy streams starting at 100.
When you initially access the stream property view, the
Conditions page on the Worksheet tab is the active page,
and 1 appears in the Stream Name cell.
3. In the Stream Name cell, replace the name by typing Feed
2, then press ENTER.
4. Enter the following values: • Temperature: 60 • Pressure: 600 • Molar Flow: 4
5. Select the Composition page and click the Edit button.
The above variable values are in the default units.
The Input Composition for Stream property view appears.
6. Change the Composition Basis to Mass Fractions by selecting the appropriate radio button, or by pressing ALT
N.
7. Click on the compositional cell for Nitrogen, type 6 for the number of parts of this component, then press ENTER. 8. Press the DOWN arrow key to move to the input cell for
Methane. Feed 2 does not contain CO2.
Figure 1.16
The current Composition Basis setting is the Preferences default. You must enter the stream composition on a mass basis.
9. Input the number of mass parts for the remaining components as shown in the following figure.
10. Click the Normalize button once you have entered the parts, and HYSYS will convert your input to component mass fractions.
11. Click the OK button to close the property view and return to the stream property view.
HYSYS performed a flash calculation to determine the unknown properties of Feed 2, as indicated by the green OK status in the status bar.
Figure 1.17
For CO2 (the component you left <empty>), the Mass Fraction was automatically forced to zero.
For streams with multiple phases, you can view the properties of each phase using the horizontal scroll bar in the table on the property view, or drag and expand the stream property view to see all the phase columns. To expand the property view, move your cursor over the right border of the property view. The cursor becomes a sizing arrow. With the arrow visible, click and drag to the right until the horizontal scroll bar disappears, leaving the entire table visible.
The compositions currently appear in Mass Fraction. To change this, click the Basis button, then select the
appropriate radio button in the Composition Basis group of the property view that appears.
Figure 1.19
Figure 1.20 Sizing Arrow cursor
To view the calculated stream properties, click the
Conditions page. New or updated information is
automatically and instantly transferred among all locations in HYSYS.
Viewing a Phase Diagram
You can view a phase diagram for any material stream using the HYSYS Envelope Utility.
1. On the property view for stream Feed 2, click the
Attachments tab, then select the Utilities page.
2. Click the Create button to create a phase envelope for the stream. The Available Utilities property view appears, displaying a list of HYSYS utilities.
3. Do one of the following:
• Select Envelope and click the Add Utility button. • Double-click on Envelope.
The Envelope Utility property view appears.
HYSYS creates and displays a phase envelope for the
stream. Just as with a stream, a Utility has its own property view containing all the information needed to define the utility.
Initially, the Connections page of the Design tab appears.
The Design tab allows you to change the name of the Utility and the stream that it is attached to, and view Critical Values and Maxima.
4. Click the Performance tab, then select the Plots page.
A Utility is a separate entity from the stream to which it is attached; if you delete it, the stream will not be affected. Likewise, if you delete the stream, the Utility will remain but will not display any information until you attach another stream using the Select Stream button.
The default Envelope Type is PT.
To view another envelope type, select the appropriate radio button in the Envelope Type group. Depending on the type of envelope selected, you can specify and display Quality curves, Hydrate curves, Isotherms, and Isobars.
To view the data in a tabular format, select the Table page. 5. Close the Utility property view.
6. Close the Feed 2 property view.