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Controller: get the final value of the controlled variable

PostPosted: 30 January 2018, 10:29
by kevin032
Dear everyone,

I have a flowsheet with controllers. The flowsheet converges with the controllers and reaches the specified values but I didn't find how to get values of the controlled variable. Could you please tell me how to get it ? Thank you very much.

Also, do you know a way to make it converge faster ?

Than you very much for your help.

Best regards,

Kevin

Re: Controller: get the final value of the controlled variab

PostPosted: 30 January 2018, 15:04
by jasper
The controlled variables are on the stream you are connecting the controller with. Double click the stream. Also the controlled variable is typically an input somewhere else (e.g. input parameter to a unit operation); you can inspect the variable there as well. For both there are several ways to 'expose' the variables short of double clicking: unit operation parameter report and stream reports, watch variables, virtual information ports, tool tips, ...

Convergence depends very much on the problem. Without looking at the problem it is hard to say anything more about it.

Re: Controller: get the final value of the controlled variab

PostPosted: 31 January 2018, 16:08
by kevin032
Thanks Jasper.

Nevertheless, when I look on the information stream or on the unit operation, I still see the initial value although I know this value must have changed because my flowsheet reached the specified value. Any idea why ?

Re: Controller: get the final value of the controlled variab

PostPosted: 31 January 2018, 18:24
by jasper
Not sure without being able to look at the flowsheet. Can you send it for inspection, or attach it?

Re: Controller: get the final value of the controlled variab

PostPosted: 31 January 2018, 18:27
by jasper
Short of that, you can remove the controller, and do a parametric study (input is controlled variable, output is measured variable). This usually explains a lot.