Ok - so I'm probably doing this all wrong.
I am trying to model a York scroll chiller in EQUEST. The table below illustrates the Part Load rating Data
Load %
Capacity (Tons)
Cond. EWT (?F)
Cond. LWT (?F)
Compressor kW
EER
COP
EIR
100
135.8
85
95
104.1
15.6
4.6
0.217391
83.3
116.8
79.4
87.9
81
17.3
5.1
0.196078
66.7
96.9
73.5
80.4
60.1
19.3
5.7
0.175439
50
73.5
66.7
71.8
41.7
21.2
6.2
0.16129
33.3
48.2
65
68.4
26.6
21.7
6.4
0.15625
16.7
23.6
65
66.6
13.1
21.7
6.4
0.15625
eQUEST doesn't seem to have a scroll chiller option - I assume screw is the closest thing to it.
As far as I can tell - you need to define 3 performance curves:
1. A curve that defines the EIR based on the condenser water temp
"York - Temp vs EIR" = CURVE-FIT
TYPE = BI-QUADRATIC-T
INPUT-TYPE = DATA
INDEPENDENT-1 = ( 85, 79.4, 73.5, 66.7, 65, 65 )
INDEPENDENT-2 = ( 95, 87.9, 80.4, 71.8, 68.4, 66 )
DEPENDENT = ( 0.217391, 0.196, 0.175, 0.161, 0.156, 0.156 )
..
2. A curve that defines the part load based on the condenser water temp
"York Temp vs Part Load" = CURVE-FIT
TYPE = BI-QUADRATIC-T
INPUT-TYPE = DATA
INDEPENDENT-1 = ( 85, 79.4, 73.5, 66.7, 65, 65 )
INDEPENDENT-2 = ( 95, 87.9, 80.4, 71.8, 68.4, 66 )
DEPENDENT = ( 1, 0.833, 0.667, 0.5, 0.333, 0.167 )
..
3. A curve that defines the EIR based on the part load.
"York Part Load vs EIR" = CURVE-FIT
TYPE = QUADRATIC
INPUT-TYPE = DATA
INDEPENDENT = ( 1, 0.833, 0.667, 0.5, 0.333, 0.167 )
DEPENDENT = ( 0.217, 0.196, 0.175, 0.161, 0.156, 0.156 )
..
When I apply these curves to my chiller, my cooling energy goes up by 30%. Seems like a lot. Is this reasonable or am I doing something wrong with my curve selection?
Muchas Gracias in advance
Vikram Sami, LEED AP BD+C
