StraighOuttaND
Petroleum
- Feb 2, 2016
- 4
Hello All,
I am in the process of doing some PID tuning on the level controllers for our refrigeration system.
I am trying to tune the Level controllers for the Economizer and Shell/Tube Chillers. The level controllers are all upstream on the vessels. The Economizer feeds 3 Chillers that maintinan a propane level to cover the tubes. The Chillers than have a back pressure controller that discharge gas back to the compressors.
Surge Vessel > Level Control Valve > Economizer >
Level Control Valve > Chiller
Level Control Valve > Chiller
Level Control Valve > Chiller
With the current tuning parameters, the system goes into a perpetual swing when there is any kind of sudden flow change in the plant. (ie surge of gas due to a PIG or dehy beds switching. The surge of Gas flashes propane at the Chillers and the level controller swings open. This will than cause a constant swing of all the level controllers until their is operator intervention.
In this kind of system does the Economizer need to have the fastest tuning to accommodate the actions of the chillers?
Control Action is Reverse
P= Gain Multiplier
I= Integral Time in Minutes
D=Derivative Time in Minutes
I am in the process of doing some PID tuning on the level controllers for our refrigeration system.
I am trying to tune the Level controllers for the Economizer and Shell/Tube Chillers. The level controllers are all upstream on the vessels. The Economizer feeds 3 Chillers that maintinan a propane level to cover the tubes. The Chillers than have a back pressure controller that discharge gas back to the compressors.
Surge Vessel > Level Control Valve > Economizer >
Level Control Valve > Chiller
Level Control Valve > Chiller
Level Control Valve > Chiller
With the current tuning parameters, the system goes into a perpetual swing when there is any kind of sudden flow change in the plant. (ie surge of gas due to a PIG or dehy beds switching. The surge of Gas flashes propane at the Chillers and the level controller swings open. This will than cause a constant swing of all the level controllers until their is operator intervention.
In this kind of system does the Economizer need to have the fastest tuning to accommodate the actions of the chillers?
Control Action is Reverse
P= Gain Multiplier
I= Integral Time in Minutes
D=Derivative Time in Minutes
