[TRNSYS-users] Differential controller - Type 2

[ali shahrouzian]

Dear TRNSYS users,



Hi,



I’m modelling a solar system to heat space. It consists of two loops: one
of them is a water-based solar collector loop as heat source and the other
one is an air-based loop including an air-to-water HX, a fan and so forth.

In order to control the solar loop in such a way that it turns off when the
incident radiation isn’t sufficient (during night), I’ve used a
differential controller (type 2). I connected the collector outlet
temperature to Th (parameter 1 for type 2) and the HX outlet temperature to
the Tc (parameter 2).

Defining the controller in this way causes the collector outlet temperature
to start from minus temperatures like -25 degrees C over the course of
winter days. I faced this issue when I used types 50 (PV/T collector), (538
evacuated collector), 539 and … , however using type 1 (flat plate
collector) as the solar collector doesn’t cause this issue.

I would appreciate it if anyone could help me in this case.



And one more thing, as I’ve already explained my system also has a
secondary loop including a fan, an air-to-water HX and … . I am wondering
whether in order to control the secondary loop when the solar loop is off,
I should define a new controller (type 2) or I can use the differential
controller previous.



Thanks in advance.

Ali
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/trnsys-users-onebuilding.org/attachments/20210809/33073608/attachment.html>