[TRNSYS-users] Type 534 Heat Exchanger dimensioning

[Matteo DF <deframat@gmail.com>]

Hi everybody,

I'm making a model which simulates a ground source solar assisted heat pump. I need to place a small tank, about 50-100 litres, before the heat pump.
This tank should be connected with the ground and to the solar collectors. So I need to have 2 immersed heat exchangers. 

I've modeled the tank using the plugin but the model behaves in a strange way. The heat coming from the solar collector is ok, the tank is heated well. Anyway the exchanger for the water coming from the ground seems to be not working. In fact if I connect only this source to the tank its average temperature raises to about 18°C but the lower temperature is at about 11°C, which is the correct value, because the water coming from the ground is at that temperature.

So I think there's a lot of stratification! Anyway I tried making some modification to the heat exchangers but they had no effect.

Can somebody help me to dimension these exchangers? They didn't have to have specific values, they just have to work in the best way...

If necessary I can attach a reducted model with the tank and the borehole only... Of course I have to attach the .dat file too...

Thanks in advance,
Matteo.

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