Hi, everyone:
What's the default equipment control when a loop with more than 1 plant?
At first I think the default should be" chiller1a- sequence 1, chiller
2a-sequence2, ..." or all the chillers with the same sequence 1.
But my experiment shows it different than my think .
I make a system with 3 chiller and make a calculation under different
control way.
The result run hour shows below:
Equipment control
Chiller 1a
Chiller 1b
Chiller 1c
None
2126
624
607
Chiller1~3 to seq 1~3
2750
607
0
All Chillers seq 1
2750
2750
2750
So I'm puzzled with how should the software control more than 1 plant
when there is no equipment control set?
Any suggestion should be appreciated.
Thank you very much.
Joey
Joey:
I am guessing, but I BELIEVE Chiller-1 gets to a certain load (think it's defined in the chiller setup), then Chiller-1 and Chiller-2 share the load until Chiller-3 is needed, when all three share the load.
See if that makes sense.
John Aulbach
Hi John & everyone:
Thank you for your helps , I just check that, but it seems different than we thought.
The PS-H report show the chiller water loop run hours. I add it in the form, so you can get it clear.
Equipment control
Chiller 1a
Chiller 1b
Chiller 1c
Chiller Water Loop
None
2126
624
607
2750
Chiller1~3 to seq 1~3
2750
607
0
2750
All Chillers seq 1
2750
2750
2750
2750
Now you can find that , the loop run hours for all control types is 2750.
If the default control type as we thought , the chiller 1a should be 2750 equal to the run hours of Chiller Water Loop, because in any situation , the chiller 1a should first and always be used.
Maybe I think too much. But it is a software , I think there must be a sample and clear way for the default control.
Thank you for your help again.
Joey
???: John Aulbach [mailto:jra_sac at yahoo.com]
????: 2012?3?22? 13:20
???: Jiao, Joey; Equest-users at lists.onebuilding.org
??: Re: [Equest-users] what's the default equipment control?
Joey:
I am guessing, but I BELIEVE Chiller-1 gets to a certain load (think it's defined in the chiller setup), then Chiller-1 and Chiller-2 share the load until Chiller-3 is needed, when all three share the load.
See if that makes sense.
John Aulbach
Joey ?
I have had the same (counter-intuitive) experience. (ie load a, then load b+c, then load b+c+d ?)
I didn?t end up solving it for my building. All my chillers were identical in capacity and part-load curve. I also had one chiller in the plant that never got turned on (ie my load never exceeded the capacity of my plant). Since those were the case, I assumed that the energy cost was the same as if there were a more intuitive control (load a, then load a+b, then load a+b+c). There appears to be an anamoly in your sample where ?b? runs by itself for a while (why?) but as long as capacity, part load, etc are identical between chiller the outputs should be similar to the intuitive loading, I believe.
I did have to do a little explaining as to why the PS-C reports came out as they did.
Aaron
Aaron Dahlstrom , PE, LEED? AP
Joey:
For your "default" case, you will note chiller-1 and chiller-2 total runs hours total 2750 hrs. I would check if you are shutting off chiller -1 and going to chiller-2 for some reason. i would have thought it to be as i originally surmise (i.e., sharing the load at each junction).