Data Sheet for Product
MVS661…N Modulating Refrigerant Valves Technical Instructions
for Ammonia (R717) and Safety Refrigerants Document Number 155-404
May 11, 2016
Siemens Industry, Inc. Page 13
k
v
theoretical = 205 kW/450 = 0.46 m
3
/h (C
V
=kvs × 1.156=0.46×1.156=0.53).
Valve MVS661.25-0.4N is suitable, since: 0.46 m
3
/h/0.4 m
3
/h × 100% = 115% (> 50%).
Capacity control
Refrigerant valve MVS661..-.. 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.
Refrigerant valve MVS661..-.. for capacity control of a chiller.
- Typical control range 10 to 100%.
- Energy-efficient operation with low loads.
- Allows wide adjustment of condensing and evaporating temperatures.
- Ideal for use with plate heat exchangers.
- Very high degree of frost protection.
Figure 8. Chiller Capacity Control.
NOTE: A larger valve may be required for low load operation than is needed for full
load conditions. To ensure that the selected valve will not be too small for low
loads, sizing should take both possibilities into account.