Data Sheet for Product

MVL661… Modulating Refrigerant Valves Technical Instructions
Valves with Magnetic Actuator Document Number 155-400
May 11, 2016
Page 13
Note on interpolation
In practice, the KE, KH or KS value can be estimated because the theoretical C
V
(k
vs
)-
value ascertained will be rounded off by up to 30% to one of the ten available C
V
(k
vs
)-
values, allowing you to proceed directly at Step 4.
Step 1: For t
c
= 95°F (35°C), calculate the value for t
o
= 14°F (-10°C) between
values 68°F (20°C) and 104°F (40°C)in the table; result: 112
Step 2: For t
c
= 95°F (35°C), calculate the value for t
o
= 32°F (0°C) between values
68°F (20°C) and 104°F (40°C) in the table; result: 109
Step 3: For t
0
= 23°F (-5°C), calculate the value for t
c
= 95°F (35°C) between
correction factors 112 and 109; calculated in steps 1 and 2; result: 111
Step 4: Calculate the theoretical C
V
(k
vs
) value; result: 2.14 (1.85 m
3
/h)
Step 5: Select the valve; the valve closest to the theoretical C
V
(k
vs)
value is the
MVL661.20-2.5
Step 6: Check that the theoretical C
V
(k
vs
) value is not less than 50% of the nominal
C
V
(k
vs
) value
Table 3. Interpolation.
KE-R407C
t
0
= 14°F
(–10°C)
t
0
= 32°F
(0°C)
Interpolation at
t
c
= 95°F
(35°C)
t
c
= 68°F (20°C)
108
85
108 + [(113 – 108) × (35- 20)/(40 - 20)]
112
t
c
= 95°F (35°C)
112
109
t
c
= 104°F (40°C)
113
117
85 + [(117 - 85) × (35 - 20)/(40 - 20)]
109
Interpolation at
t
0
= 23°F
(-5°C)
112 +[(109 - 112) × (-5 - 0)/(-10 - 0)]
111
k
v
theoretical = 205 kW/111 = 1.85 m
3
/h (C
V
=kvs × 1.156=1.85×1.156=2.14)
Valve MVL661.20-2.5 is suitable, since: 1.85 m
3
/h/2.5 m
3
/h × 100% = 74% (> 50%)
Capacity control
 Refrigerant valve MVL661..-.. for capacity control of a dry expansion evaporator.
Suction pressure and temperature are monitored with a mechanical capacity
controller and re-injection valve.
- Typical control range 0 to 100%.
- Energy-efficient operation with low loads.
- Ideal control of temperature and dehumidification.
Figure 7. Dry Expansion Evaporator Capacity Control.