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Re: [TRNSYS-users] PID controlled valve



Miguel,

 If your 3-way valve is acting as a tempering valve then there are some tempering valve components in the TESS controllers library that you can use. The difficulty in using a PID controller in a situation like yours is that the simulation time step is quite long in comparison to the time constant of the valve. If you really want to model PID then it is far easier to do with something where the time constant of the process being modeled is long in comparison to the time step of the simulation. The tempering valve model knows the temperature of the sources (A and B) and knows the temperature that you are trying to mix to so it can compute analytically the steady state solution; the ratio of A and B that will result in C.

kind regards,

 David



On 03/21/2017 08:30, Miguel Angel Reyes via TRNSYS-users wrote:

Hi all,

 

Is there any existing type of a controlled valve by using a PID.

 

In my problem I would like using three-ways valve where ports A and B are joining into an outlet C port. I would like controlling the outlet temperature of port C by modifying the opening of port B (this is from a hot recirculating stream).

 

Kind Regards

 

---------------------------------------------------

Miguel



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