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Dry cooler modelling

asked 2015-09-16 13:13:01 -0600

CY_BH gravatar image

updated 2015-11-08 11:00:09 -0600

Hi all,

I'm a beginner of OpenStudio. I have been working on a phase change material (PCM) modelling project and I try to model it in DesignBuilder. Now the problem is the system has a dry cooler as the prior equipment to supply chilled water to the chilled ceiling (PCM), but I couldn't find the dry cooler component in DesignBuilder.

  1. is it possible to model dry cooler in DesignBuilder by using another system instead? basically it's a heat exchanger of outdoor air and water (no refrigeration cycle);
  2. is Openstudio capable of modelling Phase Change Material and is dry cooler available in the system?

Thank you for any idea and suggestion!

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answered 2015-09-17 10:07:46 -0600

On the OpenStudio front:

Phase change material is modeled using MaterialProperty:PhaseChange in EnergyPlus. This object is not available directly in OpenStudio, but could be added to a model via an EnergyPlus Measure.

A dry cooler is called a FluidCooler in EnergyPlus. It is available in OpenStudio. You would attach this to the supply side of a PlantLoop.

Since DesignBuilder uses EnergyPlus as the engine, it may well already expose these objects. It should be easier to check now that you know their EnergyPlus names.

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thank you for the reply. it's greatly helpful. I tried to find FluidCooler in the latest version DesignBuilder but I still couldn't find anything relevant neither from the software nor from the tutorial manual.

CY_BH gravatar image CY_BH  ( 2015-09-17 13:27:53 -0600 )edit

answered 2015-09-17 09:54:47 -0600

updated 2015-09-17 10:31:34 -0600

There are dry coolers in EnergyPlus. The two objects for this are FluidCooler:SingleSpeed and FluidCooler:TwoSpeed.

I don't know if they are accessible in DesignBuilder for sure or not as I've not used it, but I've just found one email in my inbox that says they added Fluid Coolders to DB last June.

As far as OpenStudio: FluidCoolers just got included in the 1.9.0 release candidate. Ice Thermal Storage was already in 1.8.0.

I think the only thing you'll miss is the Material:PhaseChange object but you can access it through an E+ measure I guess.

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Thank you very much. I saw the Fluid Cooler in the feature of DB too, but I couldn't find this component in the software.

CY_BH gravatar image CY_BH  ( 2015-09-17 13:28:53 -0600 )edit

answered 2017-05-04 09:07:34 -0600

AleMac gravatar image

Hi, I would have a further question about the FluidCooler model in EnergyPlus. I am trying to figure out the sizing approach, but there is something I cannot understand.

At page 287 of the Engineering Reference document, it says that the design air flow can be calculated by the formula highlighted in red in the attach screenshot. Does anybody know the rationale behind this formula?


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answered 2017-05-05 01:56:05 -0600

banicu gravatar image

updated 2017-05-05 04:42:19 -0600

For DesignBuilder free-cooling heat exchanger go to HVAC system and select waterside economizer template. image description

Replace the cooling tower with a dry cooler. image description

Right click on CHW Loop Supply Side and chose the HX working schedule. Don’t forget to enter the HX design flow rate and free cooling and control type. Adapt your system as needed. image description

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Asked: 2015-09-16 13:13:01 -0600

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Last updated: May 05 '17