26
a)Ethylene Glycol Solutions
Water and ethylene glycol solutions used as a thermal vector in the place of water reduce the performance of the
unit. Multiply the performance figures by the values given in the following table.
cPf:
correction factor of heating/cooling capacity
cQ:
correction factor of flow rate
cdp:
correction factor of pressure drop
Freezing point ( °C)
0
-5
-10
-15
-20
-25
Percentage of ethylene glycol in weight
0
12%
20%
28%
35%
40%
cPf
1
0.98
0.97
0.965
0.96
0.955
cQ
1
1.02
1.04
1.075
1.11
1.14
cdp
1
1.07
1.11
1.18
1.22
1.24
Note:
1. During winter leaving the unit unused, please drain water out completely from unit if no anti-freeze were charged
into pipeline, or keep power on (at standby or off status) and ensure that water is contained inside of unit.
2. When ambient temperature lower than 5°C, running cooling mode must be charged antifreeze. Refers to upper
parameters for the charged volume.
b) Fouling Factors
The performance data given refer to conditions with clean evaporator plates (fouling factor=1). For different fouling
factors, multiply the figures in the performance tables by the coefficient given in the following table.
Fouling factors
Evaporator
(m²· °C/W)
f1
fk1
fx1
4.4×10-5
-
-
-
0.86×10-4
0.96
0.99
0.99
1.72×10-4
0.93
0.98
0.98
f1
: correction factor of capacity
fk1
: power input correction factor of compressor
fx1
: correction factor of total power input
