Dear all, I'm modeling on Trnsys an radiators heating system of a 3 story building from the 1980s. I'm using the Type 1231 as radiators and type 700 as Boiler. Types 1231 are connected by Type 56 as internal gain(0.8 convective; 0.2 radiative).
I have two questions / problems:
1) The internal rooms temperatures are below 20°C (comfort temperature) when the system is on. I don't understend why.
The parameters and input are:
Type 700
-Rated Capacity 248400 kJ/hr (69kW)
-Minimum Turn-Down Ratio 0.51; If I understod right it is the ratio between minimum and maximum Boiler capacity. (35kW/69kW)
- Intel fluid tempertature: i connected this input with radietors outlet temperature trought a mixing valve (type 649);
- Intel fluid flowrate: like intel fuid temperature.
- input control signal: the system work from 14.00pm to 22.00pm
- set point temperature : 80 °C
Type 1231
I inserted 13 different Type 1231, one per appartament.
- Design surface temperature is 65°C
- Design Air temperature is 20 °C
- I calcolate the flowrate as (radiator capacity)/(Cpw*deltaT) deltaT=Tin-Tout=20°C, for each type 1231
2) I want to replace the boiler with a heat pump (A-W HP Type 941) but leaving the existing radiators.
do i have change the type 1231 parameters?
For example Tsd from 65°C to 50/45°C?
Thanks a lot to everyone,
Best regards
Miriam
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