<div dir="ltr"><div><div><div>Dave and Mike,<br><br></div>Thanks for your inputs.<br><br></div>Mike,<br><br></div><div>Yes, I am referring to the multistage chiller where the liquid is flashed to the inlet of the second stage impeller. As you have mentioned this process is internal to the chiller.<br>
</div><div>My thought initially was I may have to model multiple compressors per circuit for a chiller without VFD. I did not find this option in eQUEST. As I think about it now, my case would be quite different from having multiple compressors per circuit.<br>
<br></div><div>I am in the process of obtaining data points for the chiller from the manufacturer so I can input the data points into eQUEST.<br><br></div><div>I'll keep this thread updated.<br><br></div><div>Sincerely,<br>
<br></div><div><div>Sunil Nair<br>
<p class=""><b><span style="font-size:12pt;color:rgb(31,73,125)">Ab Initio</span></b></p>
<p class=""><span style="color:rgb(31,73,125)">TMA House, Plot No. 6, 2nd
Floor,</span></p>
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Area,</span></p>
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</div><div class="gmail_extra"><br><br><div class="gmail_quote">On Wed, Aug 14, 2013 at 10:56 PM, Busman, Michael R <span dir="ltr"><<a href="mailto:MBusman@chevron.com" target="_blank">MBusman@chevron.com</a>></span> wrote:<br>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Sunil,<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">My understanding of an economizer for a multi-stage centrifugal is that some of the liquid refrigerant flashes as it passes through the expansion device. This
flash gas, I believe is introduced to the input side of the second stage impeller. Since the economizer is internal to the chiller, one set of curves should be sufficient as there is only one mode of operation as I understand it. You didn’t specify, so I’m
assuming you are not referring to a water-side economizer.<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">I haven’t custom defined a chiller yet in eQUEST, however, it appears that several performance data points from the manufacturer are required for eQUEST to
generate the curves if you select this method. The other is to generate your own curves. Many years ago when I used to work in VisualDOE, I found the calculation methodology to define chiller curves from the Pacific Gas & Electric web site, which I used
to set up a spreadsheet to calculate the curve coefficients. This was originally set up for constant speed chillers. A number of months ago I added a spreadsheet tab to handle variable speed chillers. To create the 3 sets of curve coefficients, at least
10 full load data points at different chilled and condenser water temperatures were required from the manufacturer in order to map the compressor. There was no max or min limit for the part-load data points as I recall.<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">If you’d like a copy of the spreadsheet, I can email it to you, however, you might want to check the eQUEST manual or DOE-2.2 reference manuals regarding directly
entering data points into eQUEST and let the program figure out the curves for you.<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">My best,<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">Mike Busman<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"><b><span style="font-size:7.5pt;font-family:"Verdana","sans-serif";color:#1f497d">Michael R. Busman, CEM</span></b><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:7.5pt;font-family:"Verdana","sans-serif";color:#1f497d">Lead Project Engineer II</span><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"><b><span style="font-size:7.5pt;font-family:"Verdana","sans-serif";color:#1f497d">Chevron Energy Solutions</span></b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u><u></u></span></p>
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</span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:7.5pt;font-family:"Verdana","sans-serif";color:#1f497d">eFax 866-420-0335 (Include my Full Name followed by "CAI:MHTZ" on Cover Sheet)</span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:7.5pt;font-family:"Verdana","sans-serif";color:#1f497d"><a href="mailto:mbusman@chevron.com" target="_blank">mbusman@chevron.com</a></span><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"><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>
<div style="border:none;border-top:solid #b5c4df 1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> <a href="mailto:equest-users-bounces@lists.onebuilding.org" target="_blank">equest-users-bounces@lists.onebuilding.org</a> [mailto:<a href="mailto:equest-users-bounces@lists.onebuilding.org" target="_blank">equest-users-bounces@lists.onebuilding.org</a>]
<b>On Behalf Of </b>David Eldridge<br>
<b>Sent:</b> Wednesday, August 14, 2013 9:46 AM<br>
<b>To:</b> Sunil Nair<br>
<b>Cc:</b> <a href="mailto:equest-users@lists.onebuilding.org" target="_blank">equest-users@lists.onebuilding.org</a><br>
<b>Subject:</b> Re: [Equest-users] Question: Modeling Specific Chillers<u></u><u></u></span></p>
</div>
</div><div><div class="h5">
<p class="MsoNormal"><u></u> <u></u></p>
<div>
<p class="MsoNormal">When the chiller runs on economizer it will use a separate set of curves and be modeled as a distinct chiller.<u></u><u></u></p>
</div>
<div>
<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">One set of curves will be difficult to model both modes of operation.<br>
<br>
DSE Mobile<u></u><u></u></p>
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On Aug 14, 2013, at 11:34 AM, "Sunil Nair" <<a href="mailto:energymodel.sunil@gmail.com" target="_blank">energymodel.sunil@gmail.com</a>> wrote:<u></u><u></u></p>
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<p class="MsoNormal">Hi All,<u></u><u></u></p>
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<div>
<p class="MsoNormal"> <u></u><u></u></p>
</div>
<div>
<p class="MsoNormal">I have a couple of questions with respect to modeling specific chillers.<u></u><u></u></p>
</div>
<div>
<p class="MsoNormal"> <u></u><u></u></p>
</div>
<div>
<p class="MsoNormal">1) I am trying to model a centrifugal chiller with an economizer. The chiller in question is a centrifugal chiller running on R123 with an economizer installed to it. Do I just need to get data from the chiller manufacturer and input the
curves into the model? Is this the right way to go?<u></u><u></u></p>
</div>
<div>
<p class="MsoNormal"> <u></u><u></u></p>
</div>
<div>
<p class="MsoNormal">2) How do you model multi stage centrifugal chillers without VFD's?<u></u><u></u></p>
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<div>
<p class="MsoNormal"> <u></u><u></u></p>
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<div>
<p class="MsoNormal">Thanks,<u></u><u></u></p>
</div>
<div>
<p class="MsoNormal"> <u></u><u></u></p>
</div>
<div>
<p class="MsoNormal">Sunil Nair<u></u><u></u></p>
</div>
<div>
<p style="margin:0in;margin-bottom:.0001pt"><b><span style="font-family:"Calibri","sans-serif"">Ab Initio</span></b><u></u><u></u></p>
<p style="margin:0in;margin-bottom:.0001pt"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">TMA House, Plot No. 6, 2nd Floor,</span><u></u><u></u></p>
<p style="margin:0in;margin-bottom:.0001pt"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">Main Road, Wagle Industrial Area,</span><u></u><u></u></p>
<p style="margin:0in;margin-bottom:.0001pt"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">Thane (West) - 400 604</span><u></u><u></u></p>
<p style="margin:0in;margin-bottom:.0001pt"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><a href="http://www.abinitio.co.in/" target="_blank"><span style="color:black">www.abinitio.co.in</span></a></span><u></u><u></u></p>
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