[TRNSYS-users] modulating air-source heat pump

[David BRADLEY]

Laura,

   There are various ways that heat pumps modulate and how you model 
them depends on how they modulate. Perhaps most simply some heat pumps 
contain a single speed compressor that turns on and off as required by 
the home. Those are best modeled by using a minute timestep in your 
simulation and allowing a controller model to switch the heat pump 
compressor and fan. More recently heat pumps with variable speed 
compressors have entered the market. The compressor speeds up and slows 
down to provide more or less heating and cooling as needed by the 
building. It is a bit harder to model these devices because it is 
frankly difficult to get manufacturers to say how the compressor reacts 
to changing inlet conditions. We have made some guesses about the 
internal control mechanisms and have written some heat pump components 
that modulate the compressor either to maintain a constant outlet 
temperature or to maintain a constant inlet/outlet temperature 
difference. The models do require manufacturer data but it is usually 
data that can be obtained freely online. You can contact me directly and 
I can explain in a bit more detail.

kind regards,

  David



On 09/27/2017 13:23, Laura Guillon via TRNSYS-users wrote:
>
> Hello everyone,
>
> My questions are the following :
>
>  1. How to simulate a modulating air-source heat pump with TRNSYS, in
>     order that it provides only the amount of heat required by the
>     house ?
>  2. Do the external files used to define the ASHP performance
>     represent the typical working of an ASHP ? Or do I need to find
>     data from manufacturers ?
>
> Thank you very much for your help!
>
> Laura
>
> *Laura Guillon*, Jr. Eng M.A.Sc
>
> /Project Leader/
>
>
> *cid:image001.jpg at 01CC82A8.133EEF70*
> *Natural Gas Technologies Centre*
>
> 1350 Nobel, Suite 150, Boucherville, QuebecJ4B 5H3 (Canada)
> Tel.: 450-641-0021
> laura.guillon at ctgn.qc.ca <mailto:laura.guillon at ctgn.qc.ca>
>
> www.ctgn.qc.ca <http://www.ctgn.qc.ca/>
>
>
>
> _______________________________________________
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> TRNSYS-users at lists.onebuilding.org
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-- 
***************************
David BRADLEY
Principal
Thermal Energy Systems Specialists, LLC
22 North Carroll Street - suite 370
Madison, WI  53703 USA

P:+1.608.274.2577
F:+1.608.278.1475
d.bradley at tess-inc.com

http://www.tess-inc.com
http://www.trnsys.com

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