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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>For the Chiller EIR input, below is the
equation to calculate the EIR based on the Part Load Ratio. I am modeling air
cooled chillers. <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>What is “r1” and “dT” refer to? I’m
assuming that “r1” is the actual cooling load divided by the maximum cooling
capacity based on the condenser temperature (ambient dry bulb temperature) and “dT”
is the difference between the chilled water supply and return temperature
(which is 10 with 44 supply and 54 return). I’m getting numbers that are
extremely low especially for low PLRs. I would think that the maximum
efficiency would be around 40-60% PLR but am not seeing this.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>BI-QUADRATIC-RATIO&dT The curve
is bi-quadratic in 2 independent variables. It has the form <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'> f(r1,dT)
= c1 + c2*r1 + c3*r12 + c4*dT + c5*dT2 + c6*r1*dT, <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'> where
c1, c2, c3, c4, c5, and c6 are coefficients. R1 is a dimensionless variable. dT
is a variable with units of delta temperature. <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Ian</span></font><font size=2 color=navy face=Arial><span
style='font-size:10.0pt;font-family:Arial;color:navy'><o:p></o:p></span></font></p>
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