Midea Aqua Tempto Power Series, Manual

Page: 178 / 213

Aqua tempo power series tropical air-cooled scroll chiller 50Hz MCAC-ATSM-2014-09
176
Item
Water flow rate(m3/h)
Model Minimum Maximum
MGBT-D25W/RN1
4.32 4.84
MGBT-F25W/RN1
MGBT-D30W/RN1
5.28 5.72
MGBT-F30W/RN1
MGBT-F60W/RN1 9.27 11.33
MGBT-D60W/RN1 10.08 12.32
MGBT-F120W/RN1 20.16 24.64
MGBT-F180W/RN1 27.9 34.1
MGBT-F250W/RN1 38.7 47.3
3.7 Design of the store tank in the system
a. kW is the unit for cooling capacity and L is the unit for G water flow in the formula counting the minimum
water flow.
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:
Error Recommendation
Fig.4-4
Error
Recommendation
Error
Recommendation
Fig.4-4
Error
Recommendation
Design 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 temp. 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
α
(T
2
-T
1
)
1-p
1
/p
2
T
1
=lower temp.,
o
F (
℃
)
T
2
=higher temp.,
o
F (
℃
)
V
s
=volume of water in system, gal(m
3
)