Tutorials /Deaeration /MakeUp&Feedwater

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Model Development

Simulation Diagram

Figure 2 illustrate the HYSYS simulation diagram of the  makeup and feed water system of the cogeneration plant.

Figure 2: HYSYS representation of the makeup and feed water system of the cogeneration plant

Selecting Fluid Package and Components

1. Open a new HYSYS case.
2. Select PRSV for the property package.
3. Select the component H2O. The other components are not selected here because we assume that their streams are negligible.

Setting up the PFD

1. From the object palette, select the  separator icon and install it on the PFD..

2. Enter the stream numbers for the separator as shown in Figure 3.

   

   Figure 3: Steam stripper stream names.

    

3. Install a tank on the PFD.

4. For the tank, enter : 26 for the inlet stream, 3 for the vapor outlet stream, and to feed pumps for the liquid outlet stream. Also name the tank Deaerator.

5. Install a tee on the PFD.
6. Set the stream to feed pump for the inlet of the tee.
7. Name the tee outlet streams as 4, 6, and 24.
8. Next install 3 pumps and name the outlet streams as shown in Figure 4.

   

   Figure 4: Feed Pump Stream names

    

9. Next , install a  tee.
10. Set  stream 13 as the inlet for the tee.
11. Set streams 14 and 15 for the outlets of the tee.
12. Install 2 heat exchangers.
13. Give the heat exchangers names and streams as shown in Figure 5&6.

    

    Figure 5: Stream names for exchanger 1

    

    Figure 6: Stream names for exchanger 2

     

14. Install two tees on the PFD.
15. For TEE-102, name the inlet stream, 7 and the outlet streams 8 and 9.
16. For TEE-103, name the inlet stream, 15 and the outlet streams 16 and 17.
17. Install a mixer on the PFD.
18. For the mixer, select streams 16 and 19 for the inlet streams and set stream 25 as the outlet.

Using the Adjust Logic Operation

1. Select an Adjust form the object palette and install it on the PFD.
2. Open the Adjust window.
3. In the Adjustable Variable box, press the Select Var button.
4. In the window that pops up make the selections shown in figure 7 then press the OK button.

   

   Figure 7: Selecting Adjust ed Variable

    

5. In the Adjust window, press the Select Var button located in the Target Variable box.
6. Make the Selection shown in figure 8 then press the OK button.

   

   Figure 8:  Selecting Target Variable

    

7. In the Specified Target Value box on the Adjust window, enter the temperature of stream 11 which is 195 °F.
8. Close the Adjust window and return to the PFD.

Unit Op Specifications

1. Double click on the Steam Stripper.
2. Go to the Parameters page on the Design tab.
3. Delete the value for the Delta P.
4. Remove the Delta P from the Dearator.
5. Go to the Parameters page on the Design tab of the Makeup Pump.
6. Delete the Adiabatic Efficiency number.
7. Delete the Adiabatic Efficiency for the HP feed pump.
8. Set the pressure drop (Delta P) on both sides of the  two heat exchangers to zero.
9. Open TEE-103 window.
10. Click on Parameters on the Design tab.
11. Enter 0.5 for the Flow Ratio of stream 16. (This is an estimate to get the Adjust to work.)

Specifying Streams

1. Open the workbook.
2. Go to the Workbook menu and select Setup.
3. Click on the Add button next to the list of variables.
4. In the window that opens, select the All radio button.
5. Select Comp Mole Frac from the list of variables then press the OK button.
6. Close the Setup window and return to the Workbook.
7. In the workbook enter 1 beside Comp Mol Frac [H2O] for streams 1,12, and 21.
8. Enter the stream conditions shown in table 2 except the temperature of stream 25.