<div dir="ltr">Nick,</div><div dir="ltr"><br></div><div dir="ltr">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. </div>
<div dir="ltr"><br></div><div dir="ltr">-Erik<br><div class="gmail_extra"><br clear="all"><div><div dir="ltr"><b>Erik Kolderup, PE, LEED AP</b><div><a href="mailto:erik@kolderupconsulting.com" target="_blank">erik@kolderupconsulting.com</a><span style="color:rgb(153,153,153)"> | <a href="tel:415.531.5198" value="+14155315198" target="_blank">415.531.5198</a> | </span><a href="http://www.kolderupconsulting.com" target="_blank">www.kolderupconsulting.com</a><span style="color:rgb(153,153,153)"> </span><br>
</div></div></div>
<br><br><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">---------- Forwarded message ----------<br>From: Nick Caton <<a href="mailto:ncaton@smithboucher.com" target="_blank">ncaton@smithboucher.com</a>><br>
To: Joe Huang <<a href="mailto:yjhuang@whiteboxtechnologies.com" target="_blank">yjhuang@whiteboxtechnologies.com</a>>, Esmireta <<a href="mailto:e2fye2@163.com" target="_blank">e2fye2@163.com</a>><br>Cc: "<a href="mailto:equest-users@lists.onebuilding.org" target="_blank">equest-users@lists.onebuilding.org</a>" <<a href="mailto:equest-users@lists.onebuilding.org" target="_blank">equest-users@lists.onebuilding.org</a>><br>
Date: Wed, 17 Apr 2013 19:40:31 +0000<br>Subject: Re: [Equest-users] How to set the COP of a chiller as constant in eQuest?<br>
<div bgcolor="white" lang="EN-US" link="blue" vlink="purple">
<div>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">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. <u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Example from the library:<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">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:<u></u><u></u></span></p>
<p class="MsoNormal"><img width="645" height="349" src="cid:image001.png@01CE3B79.01D745D0"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">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:<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><img width="641" height="339" src="cid:image003.png@01CE3B79.8275C180"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">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.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">~Nick<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<div>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><img width="119" height="37" src="cid:image002.jpg@01CE3B79.01D745D0" alt="cid:489575314@22072009-0ABB"></span><b><span style="font-size:11.0pt;font-family:"Stylus BT","sans-serif";color:#2d4d5e"><u></u><u></u></span></b></p>
<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Stylus BT","sans-serif";color:#2d4d5e"><u></u> <u></u></span></b></p>
<p class="MsoNormal"><b><span style="font-family:"Stylus BT","sans-serif";color:#2d4d5e">NICK CATON, P.E.<u></u><u></u></span></b></p>
<p class="MsoNormal"><span style="font-size:7.5pt;font-family:"Calibri","sans-serif";color:#cc9900">SENIOR ENGINEER<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:7.5pt;font-family:"Calibri","sans-serif";color:#cc9900"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";color:#2d4d5e">Smith & Boucher Engineers</span><span style="font-size:7.5pt;color:#cc9900"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";color:#2d4d5e">25501 west valley parkway, suite 200<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";color:#2d4d5e">olathe, ks 66061<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";color:#2d4d5e">direct <a href="tel:913.344.0036" value="+19133440036" target="_blank">913.344.0036</a><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";color:#2d4d5e">fax <a href="tel:913.345.0617" value="+19133450617" target="_blank">913.345.0617</a><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><a href="http://www.smithboucher.com" title="blocked::www.smithboucher.com" target="_blank"><span style="font-size:10.0pt">www.smithboucher.com</span></a></span><u><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";color:blue">
</span></u><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u><u></u></span></p>
</div>
<p class="MsoNormal"><br></p></div></div>
<br></blockquote></div><br></div></div>