After browsing the forums, it seems there are many users that have constructed custom chiller curves based on selection data. I believe I have all the data I need to do this, but am coming up with polynomial coefficients and hourly results that do not make sense at all. Can someone please walk me through how to go about building the 3 curves for a centrifugal, water cooled chiller with a VSD based on the following data:
% Load
Capacity
kW in
Perf
Evap T in
Evap T out
Conden T in
Coned T out
100
85
53.6
0.63
54
44
85
94.8
75
63.8
29.8
0.47
51.5
44
75
82
50
42.5
13.3
0.31
49
44
65
69.5
25
21.3
6.9
0.32
46.5
44
65
67.2
I believe the additional data I need is calculated below, except for the dT term which I am unclear on:
Load
PLR
kW
f PLR
85
1
53.6
1
63.8
0.751
29.8
0.556
42.5
0.500
13.3
0.248
21.3
0.251
6.9
0.129
Not sure if the dT term required by the curves is the difference in condenser supply and return, or condenser and evaporator supply, condenser supply and evaporator return, etc. Can someone please clarify?
Thanks
Afaan Naqvi PE LEED AP
