[TRNSYS-users] Water-Water heat pump (Type 668)

[Papafragkou A.]

Hi all,

I am using a water-water heat pump (Type 668) to simulate a domestic application.
I have various space heating demand profiles for the dwelling, therefore I use an equation with the formula Q=m*Cp*ΔT
to calculate the returning temperature of the fluid in the load loop for each time step. When I connect this returning temperature to the input
load temperature of the heat pump then both inlet and outlet load temperatures don't make any sense and they vary from -10000 to 10000 degrees C !
When I have the input load temperature of the heat pump constant, then the simulation works fine. If I use a data reader and the simulation reads
the same returning temperatures from an external file then the simulation again works fine. I also tried Type 93 (Input value recall) but it didn't work.
Any ideas what the problem may be? For the load loop the only components I use are the heat pump, one equation and a single speed pump.
I have attached all the relevant files. The heat pump is set to operate in heating mode only, therefore I haven't included the file with the cooling data.

Thank you in advance,

Anastasios




=======================
Anastasios Papafragkou
University of Southampton
School of Civil Engineering and Environment
Sustainable Energy Research Group (PhD Student)
Highfield Campus, Southampton
SO17 1BJ
Tel:(+44)02380594656
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