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(11) | EP 1 666 817 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Pressure control valve |
| (57) A pressure control valve to be integrated into a steam-compression type refrigerating
cycle (100) comprising a compressor (101) for circulating CO2 employed as a refrigerant, a gas cooler (102) for cooling the refrigerant compressed
by the compressor, an evaporator (104) into which the refrigerant is designed to be
introduced from the gas cooler, and an internal heat exchanger (103) for performing
heat exchange between the refrigerant on the outlet side of the evaporator and the
refrigerant on the outlet side of the gas cooler; the pressure control valve being
constructed to pass the refrigerant to the evaporator after adjusting, depending on
the temperature of the refrigerant on the outlet side of the gas cooler, the pressure
of the refrigerant introduced therein via the internal heat exchanger from the gas
cooler. This pressure control valve comprises: a temperature-sensing cylinder (30)
for sensing the temperature of refrigerant on the outlet side of the gas cooler; a
temperature-sensing pressure responding element (20) which is provided with a temperature-sensing
chamber (25) communicated through a capillary tube (32) with the temperature-sensing
cylinder and designed to drive a valve body (15) into a closed or open state in response
to fluctuations of inner pressure of the temperature-sensing chamber; and a valve
main body (10A) attached integrally to the pressure responding element; wherein the
temperature-sensing cylinder and the temperature-sensing chamber are filled with CO2 at a predetermined density and also with a bulking quantity of an inert gas, thereby
enabling to adjust the pressure of refrigerant on the outlet side of the gas cooler
in order to secure a maximum coefficient of performance relative to the temperature
of refrigerant on the outlet side of the gas cooler.
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