How to model a GSHP coupled with ground water open loop in E+ and/or Design Builder??

asked 2016-08-01 04:44:45 -0500

Max
11 ●2

updated 2017-04-02 20:12:27 -0500

Dear all, I am currently working on a working on a whole building energy model which includes a water-to-water ground source heat pump coupled with ground water open loop (used for both heating and cooling circuits). I was wondering if any of you could advise on how the procedures to model the above in Energy+ or Design Builder.

Look forward to hearing from you, Many thanks in advance for your kind help, Kind regards Max

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I also try to model a building with ground water open loop. If possible I would like to do so without looking into E+. If I choose the thermal conductivity and heat capacity numbers to be very high. Would this give me a return temperature from my ground heat exchanger which is close to the entered ground temperature the whole year`?

t0b1.de ( 2018-06-05 10:00:37 -0500 )edit

I am working on a similar system and am having issues with my water temperature. I specify a PlantComponent:TemperatureSource with a constant temperature of 47 F (local deep ground water temperature). I have coupled this with setpointmanager:scheduled (which is a schedule of 47 F for all days) and PlantEquipmentOperation:Uncontrolled. When I run my model and look at the CondenserLoopDemandReport:Monthly, the report is indicating a loop supply temperature of -37 C (~ -35 F) which is WAY too low. Any thoughts on why this is happenning?

njharvey1994 ( 2021-05-13 13:26:33 -0500 )edit

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answered 2016-08-01 13:06:24 -0500

Archmage

7185 ●3 ●11

In EnergyPlus, the open ground loop would be modeled using PlantComponent:TemperatureSource. The GSHP is probably best modeled with companion HeatPump:WaterToWater:EquationFit:Cooling and HeatPump:WaterToWater:EquationFit:Heating objects.

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Glad I found this!! Ok, so I have gotten the PlantComponent:TemperatureSource added, along with a setpointmanager:scheduled, PlantEquipmentOperation:Uncontrolled and PlantEquipmentList and put this temperature source on its own branch and added the branch to the plant branchlist, loops, etc...but am getting: * Fatal * CheckForRunawayPlantTemps: Simulation terminated because of run away plant temperatures, too hot .....TempSource is a 55F constant....ideas? Seems like this is a controls type thing, but not real sure what this means since all components are added and set temp...

dradair ( 2016-09-29 13:01:33 -0500 )edit

Minor note: I moved the PlantComponent:TemperatureSource componenet to the Supply Inlet branch as the second componenet after my pumps, and this "fixed" the issue....so, it runs, and the temperatures are 'believable'...but not sure it shouldn't be on its own branch. Previously, since it was parallel to a bypass branch, all flow was going to bypass and loop temp went up. This 'forces' the loops through the PlantComponent:TemperatureSource rather than giving it an alternate (bypass) branch...

dradair ( 2016-09-29 13:37:50 -0500 )edit

I am working on a similar system and am having issues with my water temperature. I specify a PlantComponent:TemperatureSource with a constant temperature of 47 F (local deep ground water temperature). I have coupled this with setpointmanager:scheduled (which is a schedule of 47 F for all days) and PlantEquipmentOperation:Uncontrolled. When I run my model and look at the CondenserLoopDemandReport:Monthly, the report is indicating a loop supply temperature of -37 C (~ -35 F) which is WAY too low. Any thoughts on why this is happenning?

njharvey1994 ( 2021-05-13 13:26:47 -0500 )edit

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answered 2016-08-02 00:17:48 -0500

Andy Tindale
121 ●3 ●2

In DesignBuilder you can model a GSHP system most easily by switching to using the Detailed HVAC model option, creating the building model and then loading one of the HVAC templates (e.g. GSHP Water to Water HP, Heated Floor and Chilled Beams) as a starting point.

You can then load manufacturer's heat pump and ground loop heat exchanger data based on the building heating and cooling loads. The simple worked example in the DesignBuilder online help explains in more detail:

http://www.designbuilder.co.uk/helpv5....

It shows a simple way to set up a heated floor and chilled beam GSHP system and size the components involved.