GB1256117A - Refrigeration system - Google Patents

Abstract

1,256,117. Valves. UNIVERSAL AMERICAN CORP. 5 May, 1969 [3 June, 1968], No. 22793/69. Heading F2V. [Also in Divisions F3-F4] In a compression-condensation refrigeration system, an expansion valve 32 is substantially balanced as to the forces applied thereto by the pressure of refrigerant on the high-pressure side of the valve. The system also has a metering orifice responsive to the temperature of refrigerant at the outlet of the evaporator 16 to position the valve to establish the flow of refrigerant to the evaporator under widely varying outdoor temperatures prevailing at the condenser 14. The valve 32, Fig. 2, comprises a body 34 having a central passage 36 therethrough connected by couplings 38, 40 into the conduit 24 from the condenser 14. The passage houses a valve member 46 with a balancing opening 50 to provide equal pressures in chambers 52, 54 at opposite ends of the member and to provide an orifice with the valve body which is oversized for normal summer outdoor temperature operation. A spring 60 biases the member 46 into a closed position in a metering orifice 48 against the action of a diaphragm 68 exposed on its bottom side to pressure in the suction line 28 from the evaporator via a passage 72 and on its upper side to pressure from a pressure-sensitive material actuated by a thermal bulb 76 in the suction line. In a modification, Fig. 3 (not shown), the diaphragm 68 is exposed on its bottom side to the pressure of refrigerant flowing into the evaporator. Two further forms of expansion valve are described wherein the valve member is responsive to motor means positioned in the suction line operating in opposition to the spring bias on the valve member, the motor means being either a bellows charged with a temperature responsive fluid, Fig. 4, or a thermal bulb which operates a diaphragm secured to the valve member, Fig. 5.