[TRNSYS-users] Controling Heatpump system

[Amdi Worm]

Dear All

I am simulating a heatpump system as attached in the PDF file.
My heatpump system is supplying both roomheating and DHW. As it is for now
the heatpump (type 927) is controlled by the temperature in the returnpipe
to the heatpump (as it is in many practical cases with a hysteresis) and
the temperature in the returnpipe where the heatpump is turned on, depends
on the outdoor temperature (lower outdoor temperature = demand for higher
return temperature).

But as my system is connected, the DHW system gets the same temperature as
the room-heating system, and in summertime due to the outdoor dependence,
the temperature is not sufficient for the DHW system. I need the outdoor
dependence according to danish law so it is not a solution just to turn it
off.

Instead I would like to model the system so that the heatpump turns on if
the temperature in the returnpipe in the roomheating curcuit goes below a
certain values, and in the same way for the DHW circuit, but here the
heatpump must turn on at another value in the returpipe of that circuit.
Is it possible to give the heatpump 2 control signals, so that it runs if
one (or both) of the criterias is met? Which controller could be used in
this case? Is it possile to create an "if / else" equation and thereby give
the heatpump a control-signal or maybe a Type 108 with roomheating as stage
one and DHW as stage two.

It is not an option for me to choose a 2 stage heatpumpe, since I haven't
been able to get sufficient cataloge-data as input.

I hope one is able to help.

Best regards
Amdi Worm

Esbensen A/S
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/trnsys-users-onebuilding.org/attachments/20130115/b6478e0b/attachment-0005.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Trnsys-system.pdf
Type: application/pdf
Size: 123944 bytes
Desc: not available
URL: <http://lists.onebuilding.org/pipermail/trnsys-users-onebuilding.org/attachments/20130115/b6478e0b/attachment-0005.pdf>