Re: [EnergyPlus_Support] Re: CentralHeatPumpSystem with one chiller/heater

["Jim Dirkes jim@xxxxxxxxxxxxxxxxxxxxxxxxxxx [EnergyPlus_Support]" <EnergyPlus_Support@xxxxxxxxxxxxxxx>]

Francesco,

from the I/O Reference: "Cooling Mode Cooling Capacity Function of Temperature ... parameterizes the variation of the evaporator capacity as a function of the leaving chilled water temperature and either the entering condenser water temperature or the leaving condenser water temperature..."

It seems that if the two curve variables are constant, as they would be when the cooling tower and chiller capacity are sufficient, the curve output would be constant.  To test this, you can report the chilled and condenser water temperatures and manually calculate the curve output.

On Mon, Jul 3, 2017 at 6:24 AM, fpasserini.tn@xxxxxxxxx [EnergyPlus_Support] <EnergyPlus_Support@xxxxxxxxxxxxxxx> wrote:

 

I'm reviewing how the curve output values of ChillerHeaterPerformance:Electric:EIR are calculated and I've plotted some graphs in excel.

Consider the attached graph.

A curve is the â??Performance Curve Input Variable 1 Valueâ?? for the â??Cooling Mode Cooling Capacity Function of Temperature Curveâ?? (CHILLERHEATERCLGCAPFT).

The other curve is the leaving chilled water temperature Tcw,l, i.e. System Node Temperature  RAFFREDDAMENTO POMPA DI CALORE CHW OUTLET NODE [C], 

I would expect that the two values are the same, but it seems that in the calculation of the curve output the â??Reference Cooling Mode Leaving Chilled Water Temperatureâ?? (constant and equal to 6.67°C) is considered instead of the leaving CW temperature from the dynamic simulation.

I don't think it's correct, is it?

Regards

--

James V Dirkes II, CEO / President
The Building Performance Team Inc.
1631 Acacia Dr, GR, MI 49504

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Posted by: Jim Dirkes <jim@xxxxxxxxxxxxxxxxxxxxxxxxxxx>

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