[Equest-users] Chiller curves

[sambhav tiwari]

Hi All,
            I am creating chilller curve for air cooled screw chiller
with manufacturer data of part load for 1 .9 .8 .7 .6 .5 .4.3.2 and
corresponding EIR at these loads with deltaT(condenser air -chilled
water leaving temperature.) at these loads

When i go with raw data points in custom curve i have to enter 6 set
of values for these three parameters ie deltaT EIR and part load with
one at ARI ie 100% load and 51F as deltaT ie(95-44)F the EIR has to be
normalized at ARI . ie EIR for ARI will be one and of other points
will be KWat given load/KW at full load.

I followed the steps and was able to get curve coefficients.

But the issue is as there are six coefficients a,b,c,d,e,f for
biquadratic equation  there will be requirement of  six set of values
for each three (part load , deltaT and EIR)  while manufacturer has
given nine set of values (1, 0.9,0.8,0.7,0.6,0.5,0.4,0.3,0.2) with
corresponding EIR and delta T for these nine part loads.

Now in raw data point entry of six which six i should select among these nine.

If i am selecting (1,0.9,0.8,0.7,0.6,0.5) and creating custom curve
with these values my cooling energy is drastically increasing than
equest default curve up to 42%


If i am selecting (1,0.8,0.7,0.5,0.4,0.3) and creating custom curve
with these values my cooling energy is coming down to 18%.


Please give me some advice

Thanks
Sambhav