Hi Matt, i have found the soloution, by connecting the PID controller directly to a heat exchanger and not to the pump to control the flow rate at the secondary side of the heat exchanger. I had the type 539 from TESS solar library but I wanted to experience it with a normal collector. Thanks, Shahrdad Date: Wed, 9 Feb 2011 13:33:12 -0600 Subject: Re: [TRNSYS-users] constant outlet temperature with controller type 22 From: duffy@tess-inc.com To: shahrdad@live.de CC: trnsys-users@cae.wisc.edu Dear Shahrad, I have never tried this but rather simply used the control output in Type539 (the TESS Library Solar Collector). It has this built in controller where all you have to do is send that control signal to the variable speed pump that is "upstream" of the solar collector in your simulation. Best regards, Matt Duffy ----- Original Message -----
From: "Shahrdad JavidRad" <shahrdad@live.de> Sent: Wed, February 9, 2011 9:33 Subject: [TRNSYS-users] constant outlet temperature with controller type 22 Dear all, I want to get a constant outlet temperature (for example 70°C) for my collector in a DHWS. For this purpose I am using a Iterative Feedback Controller (Type22) to control the the pump mass flow in my collector circuit. As Input values for this type I have entered: Setpoint: 70 Controlled variable: collector outlet temperature linked On / Off signal: 1 Minimum control signal: 0 Maximum control signal: 1 Threshold for non-zero output: 0.15 Tolerance on tracking error: 0 I have linked the control singnal of this type and the pump (type 3b) together. It should work but as I plot the collector outlet I always have no flow rate and not a constant outlet temperature from the collector. What am I doing wrong? regards, Shahrdad _______________________________________________ |