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How could I model multi-functional Heat Pump and a Ground Water Exchanger?

asked 2015-06-24 11:39:29 -0500

Elena Guidolin's avatar

updated 2015-11-09 13:29:40 -0500

Dear All,

I am trying to model a multifunctional heat pump (produces heating and cooling at the same time) that uses ground water in the condenser loop. My idea is to use an air loop connected to a chilled water loop and a hot water loop connected again to 2 condenser loops. The condenser loops operate with a vertical ground heat exchanger. The vertical ground heat exchangers simulate to exchange with water because I couldn't find a way to simulate a ground water heat exchanger.

In Openstudio I'm not able to model a water to water heat pump so I put a EIR chiller in the model just to have the nodes available, then in the IDF I change the chiller with the water to water heat pump.

And these are my questions:

Anyone of you have already tried to do a multifunctional heat pump and have some suggestion?

How could I implement the control strategy of the heat exchange between the chilled water loop and the hot water loop to produce at the same time heating and cooling saving electric energy?

Anyone of you have already tried to do a ground water heat exchanger and could help me?

Thank you very much have a nice day Elena

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Elena Guidolin's avatar Elena Guidolin  ( 2015-06-24 11:43:49 -0500 )edit

2 Answers

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answered 2015-06-24 16:40:43 -0500


If I understand you correctly you have a heat pump that is connected to a ground water system. We are modelling one of these in EnergyPlus right now. Firstly we use the watertowater:heatpump:equationfit objects for the heating coils and cooling coils in the AHU. These go straight on to the condensor loop bypassing any plant loop creation. We have one condensor loop and connect both the cooling HP and the heating HP to them.

I think you might also be able to do this directly in OpenStudio, but I am not completely sure on that. I know you can definitely do this in the idf.

I hope that helps.


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Thank you Annie for your help. By checking in E+ Guide I found Vertical Heat Exchanger, Pond Heat Exchanger, Surface Heat Exchanger and Horizontal Trench Ground Heat Exchanger. All these objects have a close water loop. What I have to simulate is a condenser system that exploits ground water that comes from an aquifer. The water taken from the aquifer is pumped directly in a heat exchanger (fluid to fluid) and then rejected in the water main. The only way I found to simulate an open loop like this is by using the object WaterUse:Well. Do you think this is the right conclusion? Thank u again!

Elena Guidolin's avatar Elena Guidolin  ( 2015-06-29 03:07:15 -0500 )edit

I have used the E+ object PlantComponent:TemperatureSource to represent an open loop ground source. The object allows for a design flow rate and a constant or scheduled temperature.

Lyle K's avatar Lyle K  ( 2015-06-29 09:57:18 -0500 )edit

answered 2015-06-24 16:43:28 -0500

updated 2015-06-24 16:45:23 -0500

You may want to investigate the E+ objects CentralHeatPumpSystem and ChillerHeaterPerformance:Electric:EIR. This is a centralized system of modular water-to-water heat pumps that can provide simultaneous heating and cooling as well as use a source/sink loop to provide additional heating or cooling if the simultaneous load is met. The source/sink (condenser) loop can be a vertical ground coupled heat exchanger as you described, or other.

There are two E+ example files that can give you an idea of the components and setup:



Below is a diagram of the system from the EnergyPlus Input-Output Referene.

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Asked: 2015-06-24 11:39:29 -0500

Seen: 168,743 times

Last updated: Jun 24 '15