Kaysun KEM-30 DNH3, Technical Manual

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MCAC-ATSM-2017-08 Aqua Tempo Power Series (with LAK) air cooled scroll chiller unit (50Hz)
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11.2.10 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
G= cooling capacity×2.6L
Process type cooling
G= cooling capacity×7.4L
b. In certain occasion (especially in manufacture cooling process), for conforming the system water content
requirement, it’s necessary to mount a tank equipping with a cut-off baffle at the system to avoid water
short-circuit, Please see the following schemes:
11.2.11Design of expansion tank
If a closed expansion tank with its filled volume of air is too small, the system pressure will easily exceed the
maximum allowable pressure and cause water to discharge from the pressure relief valve, thus wasting
water. If the closed tank is too large, when the water temperature drops, the system pressure may decrease
to a level below the minimum allowable value and cause trouble in the air vent. Therefore, accurate sizing of
a closed expansion tank is essential.
For diaphragm expansion tanks, the minimum volume of the water tank, Vt, gal(m3),can be calculated by the
following formula, recommended by ASHRAE Handbook 1996, HVAC Systems and Equipment:
V
t
=V
s
v
2
/v
1
-1-3 (T
2
-T
1
)
1-p
1
/p
2
T
1
=lower temperature,
o
F ( )
T
2
=higher temperature,
o
F ( )
V
s
=volume of water in system, gal(m
3
)
p
1
=absolute pressure at lower temperature, psia(kPa abs.)
p
2
=absolute pressure at higher temperature, paia(kPa abs.)
v
1
,v
2
=specific volume of water at lower and higher temperature, respectively, ft
3
/lb(m
3
/kg)
Error
Recommendation
Fig.4-4
Error
Recommendation
Error
Recommendation
Fig.4-4
Error
Recommendation