DX type water-cooled screw chiller (PCB Control)
MCAC-CTSM-2014-03
78
Propylene Glycol
Propylene
glycol
Evaporator side
Quality of
glycol
（
%
）
Cooling
capacity
modification
Power
modification
Water flow
modification
Water
resistance
Freezing
point
℃
30
0.968
0.969
1.01
1.16
-13
35
0.964
0.955
1.028
1.287
40
0.955
0.937
1.05
1.4
-21
45
0.945
0.914
1.078
1.502
50
0.929
0.89
1.116
1.604
-33
Condenser side
30
0.969
1.023
1.01
1.227
-13
35
0.959
1.029
1.028
1.276
40
0.944
1.039
1.05
1.329
-21
45
0.923
1.054
1.078
1.388
50
0.896
1.078
1.116
1.453
-33
Note: the freezing point not shown here, please calculate according to i
nterpolation method.
Units operating with glycol solutions are not included in the ARI Certification Program.
Altitude correction factors
Performance tables are based at sea level. Elevations other than sea level affect the performance of
the unit. The decreased air density will reduce condenser capacity and reduce the unit’s
performance. For performance at elevations other than sea level refer to below table Maximum
allowable altitude is 1800 meters.
Evaporator temperature drop factors
Performance tables are based on a 5
o
C temperature drop through the evaporator. Adjustment
factors for applications with temperature ranges from 3
℃
to 6
℃
in follow table. Temperature drops
outside this range can affect the control system’s capability to maintain acceptable control and are
not recommended.
Fouling Factor
ALTITUDE
(m)
Fouling Factor
0.018m
2
℃
/kW
0.044m
2
℃
/kW
0.086m
2
℃
/kw
0.172m
2
℃
/kw
C
P
C
P
C
P
C
P
Sea level
1.042
1.028
1.029
1.020
1.000
1.000
0.977
0.995
600
1.027
1.037
1.014
1.029
0.986
1.009
0.964
1.004
1200
1.014
1.050
1.001
1.041
0.973
1.021
0.951
1.016
1800
1.000
1.060
0.987
1.052
0.960
1.031
0.938
1.026
C--Cooling capacity
P
—Power
3).Design of the store tank in the system
a. kW is the unit for cooling capacity, L is the unit for (G) minimum water flow volume in the formula.
Comfortable type air conditioner
