Dear TRNSYS users, Hi, I’m modelling a solar system to heat a space. It is consisting 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 included 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 same way causes the collector outlet temperature starts from minus temperatures like -25 degrees C over the course of winter days. I face with 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 if anyone help me in this case. And one more thing, as I’ve already explained my system also has a secondary loop included a fan, an air-to-water HX and … . I am wondering whether in order to control the secondary loop when solar loop is off, I should define a new controller
(type 2) or I can use the differential controller previous. Thanks in advance. Ali |