See if this helps. I rouged guessed at the ODB points for each WB and the curve is still very close.
On 7/6/2015 10:52 AM,
m.waseemahmad@xxxxxxxxxxx [EnergyPlus_Support] wrote:
Hi,I have been trying to create performance curve for a VRF system. I have followed Richard's paper to create them. I am misunderstanding the way extrapolation is done. The way I extrapolated is;1) Use Cooling capacity ration function for Low and high temperatures to predict CPFT (predicted) for all temperature range (e.g. -5C to -43C) for both these curves.2) Finding the intersection of these curves (or very close points) and taking that ODB (outdoor dry-bulb) as a boundary curve point for a particular indoor wet-bulb temperature. However, by doing this I don't have any discontinuity (as points do tend to nearly overlap/intersect).3) In order to plot boundary curve, I used cooling capacity ratio boundary curve to predicted ODB for each extrapolated IWB e.g. 5C, 10C IWB etc. Then, I used that predicted temperature to calculate predicted CPFT.Please see attached performance curve for cooling. The cubic curve does not evenView attachments on the web
-- Richard Raustad Florida Solar Energy Center 1679 Clearlake Road Cocoa, FL 32922 Ph: (321)638-1454 http://www.fsec.ucf.edu/en/ Program Director Electric Vehicle Transportation Center http://evtc.fsec.ucf.edu/
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Posted by: Richard Raustad <rraustad@xxxxxxxxxxxx>
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