Gree A Series - Page 136

131
Requirements on Water Quality
Item
Chilled/Hot water
side Trend
Circulat-
ing water
Supply
water
Corro-
sion
Scalelike
sediment
Basic items
PH(25℃)
6.8-8.0 6.8-8.0 6.8-8.0 0
Conductivity
(25℃)
μs/cm
<400 <300 0 0
Cl
-
mg(Cl
-
)/L
<50 <50 0
SO
4
2-
mg(SO
4
2-
)/L
<50 <50 0
Acid
consumption
(PH4.8) mg(CaCO
3
)/L
<50 <50 0
Hardness
mg(CaCO
3
)/L
<70 <70 0
Reference
items
Fe
mg(Fe)/L
<1.0 <0.3 0 0
S
2-
mg(S
2-
)/L
undete-
cable
undete-
cable 0
NH
4
+
mg(NH
4
+
)/L
<1.0 <0.3 0
SiO
2
mg(SiO
2
)/L
<30 <30 0
Note: “○” in the table above indicates the cause for corrosion and scalelike sediment.
Even though water quality is under strict control, calcium oxide or other minerals will
gradually accumulate on the surface of the evaporator. Then, it will reduce the heat exchange
efficiency of the evaporator and consequently lead to poor performance of the unit.
Therefore, the pipe system should be cleaned periodically. Oxalic acid, acetic acid and
formic acid can be used as the organic cleaning agent, but the strong chloracid is not allowed
as it will corrode the copper tube of the heat exchanger and then lead to water and refrigerant
leakage.
■ Preparation of Materials and Tools
Several bags of environmental friendly scale remover, or similar cleaning liquid.
■ Cleaning Instructions
(1)estimate the required amount of scale remover in accordance with the system water vol-
ume and severity of scaling.
(2)add the scale remover to the water tank and the scale remover.
(3)start through the contact the water pump every 10 minutes and spread the scale remover
in water more quickly and widely.
(4)after that, follow the steps below
A Series Modular-type Air-cooled (Heat Pump) Chiller