GB898327A - High side pressure control for refrigerating systems - Google Patents

Abstract

898,327. Refrigerating. TRANE CO. March 17, 1961, No. 9902/61. Class 29 In a compression refrigeration system comprising a compressor 10, an air-cooled condenser 12, a receiver 14, an expansion valve 16 and an evaporator 18 a by-pass line 32 is connected between the condenser inlet and the line 22 connecting the condenser outlet to the receiver, and pressure responsive valve means are mounted in each of the said lines to restrict the flow of refrigerant through line 32 when the compressor head pressure is above a set value and to restrict refrigerant flow through line 22 when the pressure falls below this value. As shown in Fig. 1 the lines 22 and 32 are connected to the outer chambers of a three-way valve 24 the central chamber of which is connected to the receiver 14. Under normal conditions hot gaseous refrigerant from the compressor is supplied via line 32 to the valve chamber 50 and acts against a diaphragm 42 to urge a valve head 44 against a port 46 connecting chamber 50 to the central chamber. Should the compressor head pressure fall, a spring 52 moves the valve head 44 to open port 46 and close port 48 so that the condenser is flooded with liquid refrigerant and hot, gaseous refrigerant is supplied to the receiver 14, thus increasing the pressure at the expansion valve 16. In the modification of Fig. 2 (not shown) separate pressure responsive valves are placed in the lines 22 and 32.