Level contol dyamic stability
Level contol dyamic stability
(OP)
Hi,
We are designing a wate tank with level contol on the outlet valves. My question is how do we size the tank to provide a stable system that can handle flow changes allowing the control valves to maintain control.
Obviously a small tank will be harder to maintain control.
Is there a rule of thumb for sizing the tank liquid surface area and control range or is a full dynamic analysis with nyquist plots etc required?
Any assistance appreciated.
Ben
We are designing a wate tank with level contol on the outlet valves. My question is how do we size the tank to provide a stable system that can handle flow changes allowing the control valves to maintain control.
Obviously a small tank will be harder to maintain control.
Is there a rule of thumb for sizing the tank liquid surface area and control range or is a full dynamic analysis with nyquist plots etc required?
Any assistance appreciated.
Ben





RE: Level contol dyamic stability
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"Pumping accounts for 20% of the world's energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies) http://virtualpipeline.spaces.live.com/
RE: Level contol dyamic stability
If you are running open loop then be sure that the D.E. has all its poles in the left half plane.
What kind of control are you using? Just an on off switch?
Fe
RE: Level contol dyamic stability
The control valve will be on a PID loop on the tank outlet. Inflow is from another process over which we have no control.
Cheers,
Ben