Re: [EnergyPlus_Support] wet/dry cooling towers?

["Michael J. Witte" <mjwitte@xxxxxxxx>]

The only option I can think of for this application is to model two different 
types of chillers.  Use an air-cooled chiller(s) for the dry case, and a water-
cooled chiller(s) with tower for the evaporative case.  I will add this to the 
list of suggestions for new features in the future.  

The siwitchover can be controlled by load range or by schedule.  By reporting 
hourly chiller loads and outdoor dry bulb temperatures, you can probably come 
up with a suitable load below which the air-cooled chiller should be used.  Or 
you could take the hourly dry bulb temperatures and create two custom schedules 
(one schedules equals 1 at ODB>=6C, the other schedule equals 1 at ODB<6C) in a 
csv file and use the SCHEDULE:FILE:COMMA object to read these schedules.

Mike

On 10 Nov 2005, at 8:10, christian1855 wrote:

> Dear all,
> I'd like to simulate a building where the air-conditioning system use 
> wet/dry cooling towers. If the ambient temperature is below 6°C the 
> nonevaporative air-cooled heat exchanger portion handle the entire 
> heat load (similar to the cooling tower as described in ASHRAE, 
> Systems and Equipment p36.5, fig 13). I haven't found any according E+ 
> object. 
> Is there an object for modeling a wet/dry cooling tower?
> 
> In my case the wet and dry part of the tower did never work at same 
> time, therefore it is possible to split the tower in 2 components: 
> -) a standard cooling tower (wet) 
> -) air-cooled heat exchanger (dry)
> which use the same fan. 
> But now the next question araise: How can I model a dry cooling tower?
> 
> Christian
> 
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> 
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> 
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> 
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> 



========================================================
Michael J. Witte, GARD Analytics, Inc.
EnergyPlus Testing and Support      
EnergyPlus-Support@xxxxxxxx




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