Data Sheet for Product

12/20
Siemens Modulating refrigerant valves with magnetic actuator, PS45 CE2N4714en
Smart Infrastructure 2021-08-02
Valve sizing with correction factor
The applications and tables on the following pages are designed for help with selecting
the valves. To select the correct valve, the following data is required:
• Application
− Expansion (starting on page 12)
− Hot-gas (starting on page 16)
− Suction throttle (starting on page 18)
• Refrigerant type
• Evaporating temperature t
0
[°C]
• Condensing temperature t
c
[°C]
• Refrigeration capacity Q
0
[kW]
To calculate the nominal capacity, use the following formula:
• k
vs
[m³/h] = Q
0
[kW] / K...*
* K... for expansion = KE
for hot-gas = KH
for suction throttle = KS
• The theoretical kv value for the nominal refrigeration capacity of the plant should not
be less than 40% of the kvs value of the selected valve.
• For accurate valve sizing, we recommend the valve selection program "Refrigeration
Valve Selection Program RVASP".
The application examples on the following pages deal with the principles only. They do
not include installation-specific details such as safety elements, refrigerant collectors,
etc.
Use of the MVL661..-.. as an expansion valve
Observe engineering notes page 6
• Typical control range 20...100%.
• Increased capacity through better use of the evaporator.
• The use of two or more compressors or compressor stages significantly increases
efficiency with low loads.
• Especially suitable for fluctuating condensing and evaporating pressures.
1 = MVL661..-..
2 = evaporator
3 = compressor
4 = condenser
Electronic superheat control is achieved by using additional control equipment
(e.g. PolyCool).
Refrigerant R513A; Q
o
= 120 kW; t
o
= +5°C; t
c
= +45°C
The correct k
vs
value for the MVL661..-.. valve needs to be determined.
The important section of table KE for R513A (see page 15) is the area around the
working point. The correction factor KE relevant to the working point should be
determined by linear interpolation from the four guide values.
Note
Capacity optimization
Application example