Were using deltav tune / Deltav adapt for the first time to tune a temperature loop into a gas fire heater and the results are very disappointing.
the process gain is around 1.2, time constant about 800 seconds, dead-time around 200 seconds.
We have approved a adapt model and running the PID in partial mode.
using a tuning method of PID, and Lambda values of between 1.25 and 0.4, the response is just too slow.
When the heater starts up, the temp set-point is ramped from ambient (20°C) to 270°C, the temperature gets to around 250 then gets to set-point over a few hours which is too slow and the heater only runs for a couple of hours each batch. we need to get to setpoint ASAP with minimum overshoot.
Any ideas what im doing wrong?
In reply to James Beall:
Hi James, thanks for your continued support. model quality is between 50 - 60. the temp does go to a ratio block, then cascades to fuel flow controller and combustion air flow controllers. these do have good control. dont currently have copies of trends but could get copies tomorrow if they will be useful. the pv is following the output signal this loop was controlling good pre our deltav upgrade. It looks like we had different tuning values in our controller then what was in the upgraded database. the slides you sent were great, many thanks. would be great if i had a recording your of presentation to go with the slides, to hear the detail which goes with the slides.
In reply to Stuart Jolley:
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