Tutorials /Deaeration /Single Heat Exchanger

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Model Development

Figure 2 illustrate the HYSYS simulation diagram of the heat exchanger.

Figure 2: HYSYS representation of the heat exchanger

Model Description

A hot water stream named Tube in is fed to the tube side of the heat exchanger name E-100 and its exit stream is called Tube out. The cold water stream called Shell in is fed into shell side of the exchanger and its exit stream is called Shell out.

Selecting Components and Fluid Package

1. Open a new case in HYSYS.
2. Select PRSV for the fluid package.
3. Select H₂O for the component.

Setting up the PFD

1. Enter the Simulation Environment.
2. Select from the object palette the heat exchanger icon and install it on the PFD.

   

3. By default the installed heat exchanger should be called E-100. Double click on E-100.
4. Enter the names of the streams as shown in Figure 3.

Figure 3: Stream names for the heat exchanger.

5. Close the E-100 window and return to the PFD. Ensure that the streams are connected to the exchanger.
6. To change the icon of the exchanger, select the exchanger then right click and select Change icon from the shortcut menu.
7. In the small window that opens, select the icon that is similar to the one shown in Figure 2.

Selecting a Unit Preference

Since the number given in the problem statement are in English units, it would be easier work in HYSYS if the units are English.

1. Go to the Tools menu and select Preferences.
2. Click on the Variable tab.
3. In the Available Units box, scroll and select Field. (Field is similar to English units.)
4. In the Display Units box, notice that the temperature is in F, the pressure is in psia and the flow is in lb/hr. However, in the problem statement, the pressure was given in units of psig. To change this to psig,  press the Clone button.
5. A new Available unit set should appear with the name NewUser#. Where # stands for a number chosen by HYSYS.  Click in the box next to Unit Set Name and type in Cogen.
6. In the Display Units box, select the cell next to Pressure.
7. Go to the drop down menu located at the top of that window and scroll and select psig from the list (see figure 4).

   

   Figure 4: Selecting units from drop down menu.

    

8. After the units of the pressure has been changed, close the preference window and return to the PFD.

Stream Specifications

1. Double click on E-100 to open the E-100 window.
2. In the E-100 window, click on Worksheet tab.
3. On the Conditions page of the Worksheet tab, enter the condition given in the problem statement.
4. Since we are assuming the pressure drop across the heat exchanger is zero, enter the same pressure for the corresponding outlet stream.
5.  The should be similar to that shown in figure 5.

   

   Figure 5: Stream Conditions

6. Next click on Composition.

7. Since the only component present is water, enter 1 for the the inlet streams. After doing this the status box at the bottom of the window should turn from yellow to green. This green indicates that the heat exchanger has been solved.

8. Click on Conditions and view the Mass Flow of the cold stream.