[Bldg-sim] Chiller COP

Joe Huang yjhuang at whiteboxtechnologies.com
Fri Aug 22 11:50:19 PDT 2014


I don't know to which program you're referring, but all of them should have performance 
curves that adjust the nominal performance of the chiller based on the air or water 
temperatures, and part-load-ratio.

In DOE-2,  for example, a hermetic centrifugal chiller has a bi-quadratic curve 
(HERM-CENT-EIR-FT) with 6 coefficients that modifies the EIR as a function of the entering 
condenser water temperature (TIN) and the leaving chilled water temperature (TOUT).  There 
are default coefficients, or if you have more specific data from the manufacturer, you can 
also derive your custom coefficients.

In EnergyPlus, the chillers are modeled the same way, and in fact I recall that at least 
one of them was copied from DOE-2.

Joe

Joe Huang
White Box Technologies, Inc.
346 Rheem Blvd., Suite 205A
Moraga CA 94556
yjhuang at whiteboxtechnologies.com
http://weather.whiteboxtechnologies.com for simulation-ready weather data
(o) (925)388-0265
(c) (510)928-2683
"building energy simulations at your fingertips"

On 8/22/2014 7:33 AM, John Aulbach wrote:
> COP of chiller is 1/EIR (Energy Input ratio) in eQuest/DOE-2. There is a curve in the 
> program that relates theses parameters.
>
> John R. Aulbach, PE
>
>
> On Friday, August 22, 2014 3:59 AM, Jim Dirkes <jim at buildingperformanceteam.com> wrote:
>
>
> Sambhav,
> EnergyPlus uses several curves to define performance mathematically.  I think that is a 
> common practice for almost all energy modeling software – read up on the use of 
> performance curves!
> *James V Dirkes II, PE, BEMP, LEED AP**
> **www.buildingperformanceteam.com* <http://www.buildingperformanceteam.com/>*
> **Energy Analysis, Commissioning & Training Services**
> *1631 Acacia Drive, Grand Rapids, MI 49504USA
> 616 450 8653
> *From:*Bldg-sim [mailto:bldg-sim-bounces at lists.onebuilding.org] *On Behalf Of *Sambhav 
> Tiwari
> *Sent:* Friday, August 22, 2014 6:55 AM
> *To:* bldg-sim
> *Subject:* [Bldg-sim] Chiller COP
> Hi Friends,
>                  Is there any mathematical formula which co relates cop of chiller with 
> chilled water temperature and condenser water entering temperature.
> Warm Regards
> Sambhav
>
> _______________________________________________
> Bldg-sim mailing list
> http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org
> To unsubscribe from this mailing list send  a blank message to 
> BLDG-SIM-UNSUBSCRIBE at ONEBUILDING.ORG <mailto:BLDG-SIM-UNSUBSCRIBE at ONEBUILDING.ORG>
>
>
>
> _______________________________________________
> Bldg-sim mailing list
> http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org
> To unsubscribe from this mailing list send  a blank message to BLDG-SIM-UNSUBSCRIBE at ONEBUILDING.ORG
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/bldg-sim-onebuilding.org/attachments/20140822/0d492529/attachment.htm>


More information about the Bldg-sim mailing list