Pressure control valve

Abstract

A pressure control valve to be integrated into a steam-compression type refrigerating cycle includes: a temperature-sensing cylinder for sensing the temperature of refrigerant on the outlet side of the gas cooler; a temperature-sensing pressure responding element provided with a temperature-sensing chamber communicating through a capillary tube with the temperature-sensing cylinder and designed to drive a valve body into a closed or open state in response to fluctuations of inner pressure of the temperature-sensing chamber; and a valve main body attached 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.

1 . A pressure control valve which is adapted to be integrated into a steam-compression refrigerating cycle which comprises: a compressor for circulating CO2 employed as a refrigerant, a gas cooler for cooling the refrigerant that has been compressed by the compressor, an evaporator into which the refrigerant is designed to be introduced from the gas cooler, and an internal heat exchanger 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 that has been introduced therein via the internal heat exchanger from the gas cooler; 
 said pressure control valve comprising:    a temperature-sensing cylinder for sensing the temperature of the refrigerant on the outlet side of the gas cooler;    a temperature-sensing pressure responding element which is provided with a temperature-sensing chamber communicating through a capillary tube with the temperature-sensing cylinder and designed to drive a valve body into a closed or open state in response to fluctuations of inner pressure of the temperature-sensing chamber; and    a valve main body attached 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.    
   
   
       2 . A pressure control valve which is adapted to be disposed in the vicinity of the gas cooler or in the vicinity of the outlet port of the gas cooler of a steam-compression refrigerating cycle which comprises: a compressor for circulating CO2 employed as a refrigerant, a gas cooler for cooling the refrigerant that has been compressed by the compressor, an evaporator into which the refrigerant is designed to be introduced from the gas cooler, and an internal heat exchanger 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 that has been introduced therein via the internal heat exchanger from the gas cooler; 
 said pressure control valve comprising:    a temperature-sensing pressure responding element which is provided with a temperature-sensing chamber for sensing the temperature of refrigerant on the outlet side of the gas cooler and designed to drive a valve body into a closed or open state in response to fluctuations of inner pressure of the temperature-sensing chamber; and    a valve main body attached to the pressure responding element;    wherein the temperature-sensing chamber is 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.    
   
   
       3 . The pressure control valve according to  claim 1 , wherein the valve main body is formed of an approximately rectangular parallelepiped body which is cut out from an extruded rod having a rectangular cross-section and provided with a refrigerant entrance port, a mounting portion for the pressure responding element, and a valve seat portion for removably receiving the valve body.  
   
   
       4 . The pressure control valve according to  claim 2 , wherein the valve main body is formed of an approximately rectangular parallelepiped body which is cut out from an extruded rod having a rectangular cross-section and provided with a refrigerant entrance port, a mounting portion for the pressure responding element, and a valve seat portion for removably receiving the valve body.  
   
   
       5 . The pressure control valve according to  claim 1 , wherein the valve main body is provided with at least one engaging portion selected from an external thread portion, a flange portion, an internal thread portion for receiving bolts, and an insertion hole for attaching the valve main body to a pipe coupler or to the internal heat exchanger.  
   
   
       6 . The pressure control valve according to  claim 2 , wherein the valve main body is provided with at least one engaging portion selected from an external thread portion, a flange portion, an internal thread portion for receiving bolts, and an insertion hole for attaching the valve main body to a pipe coupler or to the internal heat exchanger.  
   
   
       7 . The pressure control valve according to  claim 1 , wherein the temperature-sensing pressure responding element comprises a diaphragm; a cap member having an inverted U-shaped cross-section for partitioning, in cooperation with the diaphragm, the temperature-sensing chamber; and a cylindrical cap-receiving member for holding, in cooperation with the cap member, an outer circumferential portion of the diaphragm to hermetically seal the pressure responding element, the cylindrical cap-receiving member comprising a flange portion for enabling the valve body to be slidably inserted therein; wherein the cap-receiving member is additionally provided on an outer circumferential wall of the cylindrical portion thereof with an external thread for attaching the pressure responding element to the valve main body.  
   
   
       8 . The pressure control valve according to  claim 2 , wherein the temperature-sensing pressure responding element comprises a diaphragm; a cap member having an inverted U-shaped cross-section for partitioning, in cooperation with the diaphragm, the temperature-sensing chamber; and a cylindrical cap-receiving member for holding, in cooperation with the cap member, an outer circumferential portion of the diaphragm to hermetically seal the pressure responding element, the cylindrical cap-receiving member comprising a flange portion for enabling the valve body to be slidably inserted therein; wherein the cap-receiving member is additionally provided on an outer circumferential wall of the cylindrical portion thereof with an external thread for attaching the pressure responding element to the valve main body.  
   
   
       9 . The pressure control valve according to  claim 1 , wherein the valve main body is further provided therein with a restraining spring for suppressing the vibration of the valve body.  
   
   
       10 . The pressure control valve according to  claim 2 , wherein the valve main body is further provided therein with a restraining spring for suppressing the vibration of the valve body.  
   
   
       11 . The pressure control valve according to  claim 9 , wherein the restraining spring for vibration is formed of an elastic plate and comprises a generally annular bottom portion having an inverted V-shaped cross-section and being press-contacted with the valve main body by the cap-receiving member, and by a plurality of tongue-shaped flexible flaps extending upward from an inner periphery of the annular bottom portion and elastically contacted with an outer circumferential wall of the valve body.  
   
   
       12 . The pressure control valve according to  claim 10 , wherein the restraining spring for vibration is formed of an elastic plate and comprises a generally annular bottom portion having an inverted V-shaped cross-section and being press-contacted with the valve main body by the cap-receiving member, and by a plurality of tongue-shaped flexible flaps extending upward from an inner periphery of the annular bottom portion and elastically contacted with an outer circumferential wall of the valve body.  
   
   
       13 . The pressure control valve according to  claim 7 , wherein the valve body and the diaphragm are disposed coaxially and one end portion of the valve body is bonded to the diaphragm by projection welding.  
   
   
       14 . The pressure control valve according to  claim 8 , wherein the valve body and the diaphragm are disposed coaxially and one end portion of the valve body is bonded to the diaphragm by projection welding.  
   
   
       15 . The pressure control valve according to  claim 7 , wherein the diaphragm comprises a closed-end shortened cylindrical body, and an outer edge portion and cylindrical portion of the diaphragm are held between the cap member and the cap-receiving member to hermetically seal the pressure responding element, wherein the lower end portion of this laminated portion is welded to each other throughout the entire periphery thereof.  
   
   
       16 . The pressure control valve according to  claim 8 , wherein the diaphragm comprises a closed-end shortened cylindrical body, and an outer edge portion and cylindrical portion of the diaphragm are held between the cap member and the cap-receiving member to hermetically seal the pressure responding element, wherein the lower end portion of this laminated portion is welded to each other throughout the entire periphery thereof.  
   
   
       17 . The pressure control valve according to  claim 7 , wherein the cap-receiving member comprises a cylindrical portion having an external thread portion, and a flange portion which can be manufactured by press-working a plate.  
   
   
       18 . The pressure control valve according to  claim 8 , wherein the cap-receiving member comprises a cylindrical portion having an external thread portion, and a flange portion which can be manufactured by press-working a plate.  
   
   
       19 . The pressure control valve according to  claim 2 , wherein the temperature-sensing chamber comprises, on an outer circumference thereof, with temperature-sensing fins, or with a temperature-sensing fin-attached cylindrical or cap body.  
   
   
       20 . The pressure control valve according to  claim 1 , wherein the valve body is partitioned into an axis portion and an enlarged portion.  
   
   
       21 . The pressure control valve according to  claim 2 , wherein the valve body is partitioned into an axis portion and an enlarged portion.  
   
   
       22 . The pressure control valve according to  claim 1 , wherein the valve seat of the valve main body comprises a plurality of bleed notches.  
   
   
       23 . The pressure control valve according to  claim 2 , wherein the valve seat of the valve main body comprises a plurality of bleed notches.  
   
   
       24 . A pressure control valve which is adapted to be integrated into a steam-compression refrigerating cycle which comprises: a compressor for circulating CO2 employed as a refrigerant, a gas cooler for cooling the refrigerant that has been compressed by the compressor, an evaporator into which the refrigerant is designed to be introduced from the gas cooler, and an internal heat exchanger 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 that has been introduced therein via the internal heat exchanger from the gas cooler; 
 said pressure control valve comprising:    a temperature-sensing inlet port for introducing therein the refrigerant from the gas cooler;    a temperature-sensing outlet port for sending the refrigerant to the internal heat exchanger;    a temperature-sensing introduction chamber interposed between the temperature-sensing inlet port and the temperature-sensing outlet port;    a temperature-sensing pressure responding element comprising a temperature-sensing chamber for sensing the temperature of the refrigerant that has been introduced into the temperature-sensing introduction chamber, the temperature-sensing pressure responding element being further capable of driving a valve body into a closed or open state in response to fluctuations of inner pressure of the temperature-sensing chamber; and    a valve main body to which the temperature-sensing pressure responding element can be attached;    wherein the temperature-sensing chamber is 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.    
   
   
       25 . The pressure control valve according to  claim 24 , wherein the valve main body comprises a solid body which is cut out from an extruded rod having a plus-shape or rectangular cross-section and provided with the temperature-sensing inlet port, the temperature-sensing outlet port, the temperature-sensing introduction chamber, the pressure-adjusting inlet port, the pressure-adjusting outlet port, a mounting portion for the pressure responding element, and a valve seat portion for removably receiving the valve body.  
   
   
       26 . The pressure control valve according to  claim 25 , wherein a guide hole for enabling the valve body to be slidably inserted therein is provided over the valve seat of the valve main body, wherein the temperature-sensing inlet port, temperature-sensing outlet port and temperature-sensing introduction chamber are disposed over the guide hole, and the pressure-adjusting inlet port, pressure-adjusting outlet port and a valve chamber are disposed below the guide hole.  
   
   
       27 . The pressure control valve according to  claim 24 , wherein the valve main body is provided with at least one engaging portion selected from an external thread portion, a flange portion, an internal thread portion for receiving bolts, and an insertion hole for attaching the valve main body to the gas cooler, to a pipe coupler for connection with the evaporator, or to the internal heat exchanger.  
   
   
       28 . The pressure control valve according to  claim 24 , wherein the temperature-sensing pressure responding element comprises a diaphragm; a cap member having an inverted U-shaped cross-section for partitioning, in cooperation with the diaphragm, the temperature-sensing chamber; and a cylindrical cap-receiving member for holding, in cooperation with the cap member, an outer circumferential portion of the diaphragm to hermetically seal the pressure responding element, the cylindrical cap-receiving member comprising a flange portion for enabling the valve body to be inserted therein through the inner periphery thereof; wherein the cap-receiving member is additionally provided on an outer circumferential wall of the cylindrical portion thereof with an external thread for attaching the pressure responding element to the valve main body.  
   
   
       29 . The pressure control valve according to  claim 28 , wherein the valve body and the diaphragm are disposed coaxially and one end portion of the valve body is bonded to the diaphragm by projection welding.  
   
   
       30 . The pressure control valve according to  claim 13 , wherein the valve body comprises a columnar valve rod, and a valve body portion formed at a lower end portion of the valve rod, wherein the valve rod comprises a shaft portion, and an enlarged portion which is formed integral with or fixedly secured to an upper portion of the shaft portion, the diaphragm being coupled to an upper surface of the enlarged portion.  
   
   
       31 . The pressure control valve according to  claim 29 , wherein the valve body comprises a columnar valve rod, and a valve body portion formed at a lower end portion of the valve rod, wherein the valve rod comprises a shaft portion, and an enlarged portion which is formed integral with or fixedly secured to an upper portion of the shaft portion, the diaphragm being coupled to an upper surface of the enlarged portion.  
   
   
       32 . The pressure control valve according to  claim 28 , wherein the temperature-sensing introduction chamber is formed between the valve rod and the cylindrical portion of the cap-receiving member.  
   
   
       33 . The pressure control valve according to  claim 28 , wherein the valve body is provided with a longitudinal hole having an open top, and the diaphragm is provided with a through-hole for enabling the temperature-sensing chamber to the longitudinal hole, thereby constituting one extended temperature-sensing chamber comprising the temperature-sensing chamber and the longitudinal hole.  
   
   
       34 . The pressure control valve according to  claim 28 , wherein the diaphragm is formed of a closed-end shortened cylindrical body, and the outer edge portion and cylindrical portion of the diaphragm are held between the cap member and the cap-receiving member to hermetically seal the pressure responding element, wherein the lower end portion of the laminated portion is welded to each other throughout the entire periphery thereof.  
   
   
       35 . The pressure control valve according to  claim 25 , wherein the valve body is provided, along the whole length of the circumferential wall thereof, with a trench for interrupting heat transmission between the temperature-sensing inlet port and the temperature-sensing outlet port, and between the pressure-adjusting inlet port and the pressure-adjusting outlet port.  
   
   
       36 . The pressure control valve according to  claim 25 , wherein the valve seat of the valve main body comprises a plurality of bleed notches.  
   
   
       37 . The pressure control valve according to  claim 30 , wherein the valve rod of the valve body comprises a plurality of annular trenches.