Temperature PID Control using two Heat Exchangers


Thread Starter


I have an application that uses two heat exchangers to control the temperature of the medium. One heat exchanger heats up the medium if required (using black steam) and the other cools it down if required (using chilled water). Both HEX have control valves installed to control the heating / cooling.

I have the control valves configured as split range.

My question is: How can I tune the PID parameters?
I use the Honeywell UDC 3200 PID controller specifically because its autotuning algorithm tunes what they call a duplex loop - heat/cool split range.

There's a setting for "Duplex Tune" that tunes both the heating and cooling sides of the process.

It's worked fine on water exchangers and a steam exchanger.


Dick Compton

What controller do you have already?

There may be a parameter called "cool gain ratio" to change the cooling PID vs the heating PID.