[EnergyPlus_Support] Re: CentralHeatPumpSystem with one chiller/heater [2 Attachments]

In the aquifer loop Iâ??m using PlantComponent:TemperatureSource (constant and equal to 13Â°C)

Iâ??ve found no example file where both PlantComponent:TemperatureSource and CentralHeatPumpSystem are present.

-1. - For the aquifer loop is PlantLoop or the CondenserLoop object the best solution?

2. - Which kind of setpoint manager (scheduled?) shall be used? With which value (the same temperature of the temperaturesource, i.e. 13Â°C?)?

-3. - Which kind of Plant Equipment Operation scheme shall be used? PlantEquipmentOperation:Uncontrolled?

Now I have replaced the PlantLoop with the CondenserLoop and the system works also in chiller mode, but only in winter... When I used the PlantLoop it was never working in chiller mode.

Raffreddamento Pompa di Calore CHW Outlet Node, !- Cooling Loop Outlet Node Name

ChillerHeaterPerformance:Electric:EIR, !- Chiller Heater Modules Performance Component Object Type 1

Circuito di Condensazione Funzionamento, !- Plant Equipment Operation Scheme Name

Circuito di Condensazione Supply Side Outlet, !- Loop Temperature Setpoint Node Name

Circuito di Condensazione Rami del lato di Alimentazione, !- Plant Side Branch List Name

Circuito di Condensazione Connessioni del lato di Alimentazione, !- Plant Side Connector List Name

Circuito di Condensazione Rami del Lato della Domanda, !- Demand Side Branch List Name

Circuito di Condensazione Connessioni del Lato della Domanda, !- Demand Side Connector List Name

Circuito di Condensazione Lista dei Manager di Disponibilità¬ !- Availability Manager List Name

Circuito di Condensazione Setpoint Manager Node List; !- Setpoint Node or NodeList Name

A strange result (actually, I get many strange results): as you can see in the attached images, in the results the â??Chiller Heater System Source Mass Flow Rateâ?? is different from the water flow rate through the condenser (the second one is constantly equal to 0!). I thought they were the same.

---In EnergyPlus_Support@xxxxxxxxxxxxxxx, <fpasserini.tn@...> wrote :

"Properly" should mean that E+ is using the â??actual chilled water temp and actual condenser water temp. Is that the case?

It's using the "Performance Curve Input Variable 1 Value", the "Performance Curve Input Variable 2 Value" and the parameters defined in the curve to calculate the "Performance Curve Output Value". The problem is that it is not using the correct value of "Performance Curve Input Variable 1 Value", in my opinion. So, wrong input -> wrong output (sorry, I was not clear).

Is the setpoint manager value different than the "reference" temperature?â??

Yes,

â??Reference Cooling Mode Leaving Chilled Water Temperatureâ?? = 6.7Â°C

setpoint manager temperature = 6Â°C

for CHILLERHEATERCLGCAPFT it's using 6.7Â°C

for CHILLERHEATERCLGEIRFT it's using 6.0Â°C

In both cases I would expect the temperature from the dynamic simulation, which is higher (15-16Â°C), because the system is not working properly.

You'll need to determine why the chiller does not operate for more than one hour. That may â??be part of the reason for the curve output problem.

Ok. Actually I was thinking in the other way: the chiller/heater doesn't operate properly, is the problem relative to the curves (or to the points of the curves where the system is operating)?

---In EnergyPlus_Support@xxxxxxxxxxxxxxx, <jim@...> wrote :

Francesco,

Comments below...

On Mon, Jul 3, 2017 at 8:46 AM, fpasserini.tn@... [EnergyPlus_Support] <EnergyPlus_Support@xxxxxxxxxxxxxxx> wrote:

Hello, Jim
The source/condenser temperature is constant because the PlantComponent: TemperatureSource object is used.
The calculated output is constant. I have recalculate the output in excel, considering the parameters used for the curve, and the polynomial formula is calculated by EnergyPlus properly.
â??"Properly" should mean that E+ is using the â??actual chilled water temp and actual condenser water temp. Is that the case?
The strange issue is that the leaving chilled water temperature used in the calculation is not taken from the dynamic simulation but it is the â??Reference Cooling Mode Leaving Chilled Water Temperatureâ??.
â?? Is the setpoint manager value different than the "reference" temperature?â??
I have plotted the â??Cooling Mode Electric Input to Cooling Output Ratio Function of Temperatureâ?? (CHILLERHEATERCLGEIRFT) too and Iâ??m attaching it now. As for that curve, the temperature 6Â°C, which is the setpoint manager temperature, is considered as leaving chilled water temperature!?
As you can see in the second picture, the chiller-heater is working in cooling mode only one hour. Therefore the setpoint manager temperature is not met.
â?? You'll need to determine why the chiller does not operate for more than one hour. That may â??be part of the reason for the curve output problem.
Best Regards

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