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Open Loop Ground Source Heat Pump in E+

asked 2021-05-13 13:31:42 -0500

njharvey1994's avatar

updated 2021-05-17 14:34:55 -0500

I am working on modeling an open loop geothermal heat pump in E+ and am having issues with my water temperature. I have read one post about how to model an open loop system by using PlantComponent:TemeratureSource which is what I used for model. 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 happening and how I might be able to fix it?

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attached is a link to my IDF file.

njharvey1994's avatar njharvey1994  ( 2021-05-14 10:42:18 -0500 )edit

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answered 2021-05-24 17:29:24 -0500

The main issue is using PlantEquipmentOperation:Uncontrolled for your Condenser loop control scheme. If you replace this with PlantEquipmentOperation:HeatingLoad it works as expected.

Also, your IDF is missing the Version object (I guessed 9.3 and it ran fine). And while not entirely necessary, you may consider changing your SetpointManager:FollowGroundTemperature to SetpointManager:Scheduled since you just want to maintain a constant 8.3C supply water setpoint.

I sorted the original and fixed IDFs so you can easily compare the two files to see what changed.

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Asked: 2021-05-13 13:31:42 -0500

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Last updated: Jun 11 '21