VISSIM Valve Experimental Procedures

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Description

VISSIM Valve Experimental Procedures

 

When walking in the lab there are tasks that must be performed every time before starting the experiment, while running the experiment, and to end the lab for the day.

VISSIM Valve Experimental Procedures

  1.  The first step involves one member of the group logging into the computer  by sing their Chemical Engineering Department credentials
  2.   The group member then opens the VISSIM file
  3. The next step is turning on the heat exchanger. This is done by just flipping the switch, which is found on the heat exchanger box.
  4. Open the pneumatic valve in order to allow the control valves to work with VISSIM
  5. Then the cold-water valve should be opened to generate a flow rate of 10gpm when the water valve in VISSIM is set at 10.  This will create consistency since there is change in water pressure from day to day.
  6. Open fully the steam valve to allow steam into the heat exchanger.
  7. We use open-loop tuning method to tune the feedback controllers. This will provide a rough estimate of ôI and KC. We use the estimate values to refine the controller.
  8. In the feedforward controller we have a Qloss term which is deduced from Cpw*mw*(Two-Twi) side of equation. Qloss term is found by guessing and checking until the temperature controller records temperature close to the temperature set point.
  9. At this point, every part of the experiment is ready and VISSIM file, which has controllers, should be used to collect data.VISSIM Valve Experimental Procedures
  10. The collected data should be saved in an accessible location.  This is achieved by adjusting the export block and selecting the “append to file” option.
  11. Select set points for both flow rate and temperature and adjust the slide bars in VISSIM to attain these set points. This is done by clicking the green button in VISSIM.
  12. Allow the system to reach steady rate. Once the system settles at steady rate make a step change of 1gpm or 20 °F.
  13. Again when the system attains a steady rate record the POR when performing a step change in temperature. When carrying out a step change in flow rate make note of the temperature deviation from the set point while ensuring that there no more than 1 °F deviation from the set point. Similarly, one has to ensure that the average flow rate does not deviate by more than 0.2 gpm. One has to use excel in order to get the average value.
  14.  Repeat the steps 10 and 11 for every trial and carry out numerous tests in order to get results that are more accurate.
  15. End the lab by clicking on the red stop button on VISSIM. Then save the file into the folder of the group member who logged into computer.
  16.  Close the chain steam valve by pulling down the chain and making the valve turn clockwise.VISSIM Valve Experimental Procedures
  17.  While wearing a pair of gloves climb the ladder and close the hand steam valve.
  18.   Close the cold water and the pneumatic valves
  19.  Finally, switch off the heat exchanger box by flipping off, log out of the account on the computer, and shut down the computer.