Johnson Controls YEWS Series, Installation, Operation And Maintanance Instructions

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Quality requirement of water used in chiller
Name
PH value(25
℃
)
Conductivity(25
℃
)
Chloridion
Sulphate ion
Acid wastage
Total Hardness
Calcium Hardness
SiO
2
Unit
-
μ
s
/cm
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
6.5
～
8.0
＜
800
＜
200
＜
200
＜
100
＜
200
＜
150
＜
50
Corrosion
X
X
X
X
Target
Allowable value
Fouling
X
X
X
X
Notes:
1. The user should make regular inspections on the water
quality before installation and in the process of using. If the
water quality does not meet the demands of using, the heat-
exchange tubes will be in the danger of fouling ,corrupting
and even leakage when using the
“
Defective
”
water for
long term.
2. Corrupting testing about the influence of using
“
Def-
ective
”
water whose qulity exeed the limits for long term
shows that, the chiller will fail to run normally due to the
heat-exchange tubes corrupting and leakage.
3. Fouling testing about the influence of using
“
Defecti-
ve
”
water whose qulity exeed the limits for long term
shows that, the chiller will has a decreaing on capacity due
to the heat-exchange tubes fouling.
4. The water should be drained out if the unit will stop for a
long time, it is suggested that the heat exchanging pipe
should be cleaned after each long-term stop.
5. User should be responsibility for the loss caused by the
poor water quality.
4.6 Pipework Arrangement
The following are suggested pi4pework arrangements for
single unit installations. For multiple unit installations, each
unit should be piped as per relative drawings.
4.7 Connection Types &Sizes
Please refer to Section 10 for connection sizes of each
model.
The piping connections of evaporator and condenser are
HG20615 welded flanges.
4.8 Refrigerant Relief Valve Piping
The evaporator and condenser are each protected against
internal refrigerant overpressure by refrigerant relief valves.
It is recommended that each valve should be piped to the
exterior of the building so that when the valve is activated
the release of high pressure gas and liquid cannot be a
danger or cause injury.
The size of any pipework attached to a relief valve must be
of sufficient diameter so as not to cause resistance to the
operation of the valve. Unless otherwise specified by local
regulations, the internal diameter depends on the length of
pipe required and is given by the following formula:
YEWS-E Water Cooling Screw Chiller/Heat Pump
4.5 Water Treatment
The unit performance provided in the Design Guide is
2
based on a fouling factor of (0.044m .
℃
/KW for
2
condenser and 0.0176m .
℃
/KW for evaporator). Dirt,
scale, grease and certain types of water treatment will
adversely affect the heat exchanger surfaces and therefore
the unit performance. Foreign matter in the water
system(s) can increase the heat exchanger pressure drop,
reducing the flow rate and causing potential damage to the
heat exchanger tubes. YORK recommends that a water
treatment specialist should be consulted to determine
whether the proposed water composition will adversely
affect the evaporator materials of carbon steel and copper.
The pH value of the water flowing through the evaporator
must be kept in a range between 6.5 and 8.0. The water
quality of chiller should be in accordance with local code.
15