Chiller always requests full condenser flow regardless of flow mode or pump type

NREL / EnergyPlus

EnergyPlus™ is a whole building energy simulation program that engineers, architects, and researchers use to model both energy consumption and water use in buildings.

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Chiller always requests full condenser flow regardless of flow mode or pump type #7111

Closed mjwitte closed 2 days ago

mjwitte commented 5 years ago

Issue overview

User file with Chiller:Electric:EIR always requests full condenser flow rate, regardless of chiller flow mode, with variable speed towers and variable speed condenser pump. Should this happen? If so, should there be an additional flow mode to allow variable flow condenser?

Details

Some additional details for this issue (if relevant):

Version of EnergyPlus 9.0.1
Unmethours 35540 link and helpdesk ticket 13133.

Checklist

Add to this list or remove from it as applicable. This is a simple templated set of guidelines.

[x] Defect file added EnergyPlusDevSuppor\DefectFiles\7000s\7111
[ ] Ticket added to Pivotal for defect (development team task)
[ ] Pull request created (the pull request will have additional tasks related to reviewing changes that fix this defect)

mjwitte commented 3 years ago

Certainly looks like this should be an option. How to control it is another question. Here's one article about that: https://www.csemag.com/articles/control-sequences-for-chilled-water-systems/

dmitry-ivanov-mm commented 2 years ago

Hi there,

Is there a way to raise the priority of this issue? It hasn't been addressed since 2018 and makes results for the variable-speed condenser loop very inaccurate. At the same time variable-speed condenser loops are very common design.

Just trying to attract attention to this issue :)

Cheers

giorgiolupato commented 2 years ago

Hi there,

Is there a way to raise the priority of this issue? It hasn't been addressed since 2018 and makes results for the variable-speed condenser loop very inaccurate. At the same time variable-speed condenser loops are very common design.

Just trying to attract attention to this issue :)

Cheers

Hi, unfortunately this is not a complete solution, but it can be a workaround (it's not perfect at all).

https://unmethours.com/question/40084/condenser-water-flow-rate-with-ems-energyplus/

keigo-nomura commented 1 year ago

Still unresolved?

This is a problem not only when using cooling towers, but also when using seawater cooling by PlantComponent:TemperatureSource. Unlike cooling towers, it is not possible to make a compromise of variable tower fans instead of variable condenser water.

Or variable condenser flow is possible with any other chiller objects?

Hope this issue won't be left unattended forever.

keigo-nomura commented 1 day ago

Great to hear that. Will the new feature be available in v24.2.0?

lymereJ commented 1 day ago

Yes. Note that the ASHRAE 205 chiller object doesn't include this feature but will be implemented a bit later.