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

[David Bradley]

Knut Erik,
  Very interesting. I would think that the data-file format would also 
have had to change since I imagine that the device would require 
different fractions of full load power as the compressor speed modulates.
Best,
 David


knut.erik.enerstvedt at niva.no wrote:
>
> 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!!!
> ------------------------------------------------------------------------------------------------------------
> Meld deg på vårt nyhetsbrev på www.niva.no 

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