Product Overview

The control valve throttles the capacity of a compressor stage. The hot gas is injected
directly into the evaporator allowing capacity control from 100 % to approximately 0 %.
•
Suitable for use in large refrigeration systems in air conditioning applications, to
prevent unacceptable fluctuations in temperature between compressor stages.
The pressure differential
∆
p
v100
across the fully-open valve is determined by the
condensation pressure at low load minus the pressure upstream of the evaporator.
If no details are provided, the pressure differential
∆
p
v100
can be assumed to be 4 bar.
94.0241A
+
–
3
1
Example :
Refrigeration capacity Q
o
of one
compressor stage
Refrigerant
Condensation temperature full/low load
Evaporation temperature full load/low load
Liquid temperature t
fl
Pressure differential
∆
p
v
(from R22 vapour
table)
Selected valve
Actual capacity
30 kW
R22
45 / 35 °C
5 / 15 °C
40 / 30 °C
5.6 bar
M3FB15LX/A
appr. 40 kW
The control valve throttles the capacity of a compressor stage. The gas is fed to the
suction side of the compressor and cooled by a re-injection valve. Capacity control
range from 100 % to approx. 10 %.
•
Suitable for large refrigeration systems for air conditioning, with several compressors
or compressor stages, and where the evaporator and compressor are some distance
apart (attention must be paid to oil return).
The pressure differential
∆
p
v100
across the fully-open valve is determined by the
condensation pressure at low load minus the suction pressure.
If no details are provided, the pressure differential
∆
p
v100
can be assumed to be 6 bar.
50942
+
–
3
1
Example :
Refrigerant capacity of one compressor
stage
Refrigerant
Condensation temperature full/low load
Evaporation temperature full load/low load
Liquid temperature t
fl
Pressure differential
∆
p
v
(from R22 vapour
table)
Selected valve
40 kW
R22
45 / 35 °C
2 / 10 °C
40 / 30 °C
6.5 bar
M3FB15LX/A
The hot-gas diverting valve may be used for modulating recovery of the heat from the
condenser, even in the event of high pressure differentials.
Recommended pressure drop
∆
p
v100
across the fully-open valve
(control path 1 –> 3) : between 0.5 and 1 bar.
94.0243A
+
–
+
3
2
1
Example :
Refrigeration capacity Q
Refrigerant
Condensation temperature t
c
Evaporation temperature t
o
Liquid temperature t
fl
Selected valve
Actual pressure drop
67 kW
R134a
50 °C
2 °C
45 °C
M3FB32LX
0.7 bar
Indirect hot-gas bypass
Direct hot-gas bypass
Heat recovery
Beijing shenglanjieneng Electromechanical Company TEL:[phone] FAX:[phone] www.bjsljn.com