[Bldg-sim] Fraction of Hour Chiller Operates calculation

[Aaron.Etzkorn at tac.com]

I am trying to sift through how eQuest calculates a chiller's end
electrical usage and I am stuck on the fraction of hour the chiller
operates. 
The DOE-2 engineers manual says it is calculated as follows:
 
FRAC = PL / RMIN,
 
where PL is the average part load ratio over the hour, calculated as:
 
PL = ALOAD / CAP,
 
where ALOAD is the assigned hourly load and CAP is the corrected
operating capacity.
 
RMIN is the part load ratio of rated load at which the chiller can
operate continuously.
 
I have used some of the calculated values in the hourly report and
cannot verify how eQuest is calculating this FRAC amount.
 
Does anyone have some insight? 
 

Thanks,

Aaron Etzkorn, EIT
Engineer I

TAC
16011 College Blvd, Suite 212
Lenexa, KS  66219

Direct:  +1 (913) 469-0203  
Fax:      +1 (913) 469-0206
Mobile:  +1 (913) 620-3291
Email:   Aaron.Etzkorn at tac.com
Web:     www.tac.com <http://www.tac.com/> 

Notice: This email message, together with any attachments, contains
information of TAC, which may be confidential, proprietary, copyrighted
and/or legally privileged. This email is intended solely for the use of
the individual or entity named on the message. If you are not the
intended recipient, and have received this message in error, please
immediately return by email and then delete it.  

 

P  Please consider the environment before printing this e-mail. Thank
you.

 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/bldg-sim-onebuilding.org/attachments/20081016/6d21cc64/attachment.htm>