Ethyline Glycol Application - Hitachi RCUE40AG1 Installation, Operation And Maintenance Instructions

Model: RCUE300AG1, RCUE330AG1
Ambient
Performance
Temperature
Capacity
35°C Input
COP
Capacity
30°C Input
COP
Capacity
25°C Input
COP
Capacity
20°C Input
COP
: Standard Condition (Ambient: 35°C, Water Inlet/Outlet: 12/7°C, Full Load)
NOTE:
1. Capacity: Cooling Capacity (kW)
Input: Total Input Power (Compressor + Fans) (kW)
COP: Capacity/Input (kW/kW)
2. Operating Conditions:
Chilled Water Outlet Temperature:
Water Flow Rate:
Condenser Fan:
3. Above Table shows the percentage of Capacity, Input and COP
based on the standard condition.
Therefore, each value can be calculated as below example:
Example: Model RCUE100AG1
Standard Condition Ambient: 30°C, Capacity 70%
Capacity: 246 kW Capacity:
Input: 84.2 kW Input:
COP: 2.92 COP:
4. Control marked (*) is available by the optional selection switch.
DSW7-3 / ON: Minimum Load Extension.
16.3. ETHYLENE GLYCOL APPLICATION
" Low Ambient Application
Under the condition where the ambient temperature is low
in winter, there is a case where the unit and piping will
become damaged by freezing during the shutdown periods.
To prevent freezing, it is effective to operate the pump.
This Chiller has the pump ON/OFF operation control to
avoid freezing. This control become available by
connecting Pump Operation circuit. (See Wiring Diagram).
Additionally, in a case where measures such as water
raining are difficult, utilise antifreeze mixture of ethylene
glycol.
Below table shows the ethylene glycol percentage
suggested for the different temperature values.
The table also shows the correction factors, since unit with
antifreeze mixture have a slight different performance
compared with no glycol.
Example:
− Cooling Capacity with ethylene glycol = Kc × Cooling
Capacity without ethylene glycol
− Input Power, Flow Rate and Pressure Drop is calculated
in the same way as Cooling Capacity
10%
(*)
% 12 30 40 50
% 14 35 38 43
% 86 86 105 116
% 13 32 40 50
% 13 32 34 38
% 100 100 118 132
% 13 34 40 50
% 12 29 30 34
% 117 117 133 147
% 14 35 40 50
% 4 26 28 30
% 135 135 143 167
7°C
Constant
All Fans Running
246 × 0.7 = 172 kW
84.2 × 0.5 = 42.1 kW
2.92 × 1.4 = 4.09 kW
APPLICATION DATA
Compressor Load
25~100%
60 70 80 90
48 56 67 80
125 125 119 113
60 70 80 90
42 50 57 67
143 140 140 134
60 70 80 90
37 42 50 59
162 167 160 153
60 70 80 90
32 36 42 50
188 194 190 180
(Water Outlet Temperature: 5 ~ 15°C)
Minimum Ambient
Temperature
Required Ethylene Glycol
Percentage
Cooling Capacity Correction
Factor
Input Power Correction Factor
Flow Rate Correction Factor
Pressure Drop Correction
Factor
"
Low Water Temperature Application (Option)
When utilising water less than 5 °C, antifreezing mixture of
ethylene glycol shall be input to the water system.
Low water temperature Option is categorised 3 level
depending on water outlet temperature.
Therefore, please specify the level when ordering .
Freeze Protection Thermostat has been set in the factory.
Table shows Required Ethylene Glycol percentage for each
category.
16
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Full Load
100
100
100
100 106
83 94
120 113
100 112
70 88
143 127
100 110 120
57 67 80
175 164 150
°C -3 -7 -13 -22
wt% 10 20 30 40
Kc 0.99 0.98 0.97 0.96
Ki 1.00 0.99 0.99 0.98
Kf 1.00 1.01 1.04 1.08
Kp 1.04 1.11 1.18 1.29