[TRNSYS-users] outlet temperature, water to water heat pump

[knut.erik.enerstvedt at niva.no]

Mavi and David,

A heat pump with a variable speed compressor can fix the outlet 
temperature, but they are not very common yet. I once thought I had to 
model such a heat pump, so I made some modifications to Type 668 
water-water heat pump to include a set point on outlet load temperature, 
similar to Type 666 water cooled chiller which has a set point temperature 
on the chilled water stream. It was hard to find data on part load 
performance, however. Later I found out that I did not need this model 
after all.

Mavi, let me know if you need more information about the modified heat 
pump component.


Best regards,
Knut Erik Enerstvedt
 

>Mavi,
> Heat pumps can't really do that - they are either on and operating at 
whatever capacity they have available given the entering water >conditions 
or they are off. Unless they are multistage heat pumps, they can't load 
follow and provide a constant outlet temperature >regardless of the inlet 
temperature. In reality and in simulation, you would have to look for a 
method of actually doing that. One thing >you could try is to have a 
bypass valve upstream of the heat pump, oversize the heat pump so that it 
can always heat or cool the >liquid enough and then divert some of the 
upstream liquid around the heat pump and mix it back in downstream like a 
tempering >valve.
>Best, 
> David


>Mavi Cambronero Vázquez wrote: 
>Hi everybody!!
 
>I´d like to get a fixed outlet temperature from a water-water heat pump. 
Do you know how to do it???
 
>Thank you!!!
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