[Equest-users] How to set the COP of a chiller as constant in eQuest?

[Erik Kolderup]

Nick,

One point of correction regarding curves to provide constant COP... I'm
pretty sure you do not want the EIR-FPLR curve to be constant 1.0. The
value of that curve is actually (normalized EIR)*(part load ratio). So if
you want constant EIR, then the curve should just equal PLR. That's a
straight line between (0,0) and (1,1). So the "a" coefficient should be
zero and the "b" coefficient should be 1.0. All other coefficients for that
curve should be zero.

-Erik

*Erik Kolderup, PE, LEED AP*
erik at kolderupconsulting.com | 415.531.5198 | www.kolderupconsulting.com


---------- Forwarded message ----------
> From: Nick Caton <ncaton at smithboucher.com>
> To: Joe Huang <yjhuang at whiteboxtechnologies.com>, Esmireta <e2fye2 at 163.com
> >
> Cc: "equest-users at lists.onebuilding.org" <
> equest-users at lists.onebuilding.org>
> Date: Wed, 17 Apr 2013 19:40:31 +0000
> Subject: Re: [Equest-users] How to set the COP of a chiller as constant in
> eQuest?
>
> After identifying the curves in play per Joe’s suggestion, you could
> achieve a constant COP, independent of part load or other variables, by
> making a set of custom curves (of appropriate/acceptable type) using
> coefficient inputs.  ****
>
> ** **
>
> Example from the library:****
>
> ** **
>
> CentH2O-EIR-fPLR&dT looks like this from the library before modification.
> This curve works alongside others to determine how to modify the input EIR
> for a chiller:****
>
> ****
>
> ** **
>
> What we want is for this and all the other curves to return a value of
> 1.0, whatever the hourly variables throw at it.  Simply enter all
> coefficients preceding a variable (b,c,d,e,f) to 0.  Set the coefficient
> for the curve’s constant (a) at 1.0:****
>
> ** **
>
> ****
>
> ** **
>
> Doing the same for all associated curves (again, read up in the
> help/documentation for your particular equipment to be sure), at all hours
> the chiller in question will operate at the specified EIR without variance.
> ****
>
> ** **
>
> ~Nick****
>
> ** **
>
> [image: cid:489575314 at 22072009-0ABB]**
>
> * *
>
> *NICK CATON, P.E.*
>
> SENIOR ENGINEER****
>
> ** **
>
> Smith & Boucher Engineers****
>
> 25501 west valley parkway, suite 200****
>
> olathe, ks 66061****
>
> direct 913.344.0036****
>
> fax 913.345.0617****
>
> www.smithboucher.com* *****
>
>
>
>
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