GB877034A - Refrigeration system - Google Patents

Abstract

877,034. Refrigerating. BODCHER, H. F. V. Aug. 27, 1958 [Aug. 29, 1957], No. 27526/58. Class 29 In a compression system a valve 5 between the receiver 3 and the evaporator 6 is opened when the receiver pressure reaches a predetermined maximum and closes when it reaches a predetermined :minimum. In operation, valve 5 being closed, the compressor withdraws refrigerant from the evaporator and supplies it to the condenser 2 and receiver which fills with liquid. Ultimately the condenser also begins to fill thus reducing its effective heat exchange capacity and the pressure rises. This causes valve 5 to open and the receiver empties into the evaporator, the relatively warm refrigerant effecting defrosting, and the resulting drop in receiver pressure causes closure of valve 5. The suction pressure then lowers the refrigerant temperature in the evaporator and the next cycle follows. As shown evaporator 6 discharges into an accumulator 7 from which liquid is led through a check valve 9 and pipe 8 to the evaporator inlet. The evaporator may be protected by a grid. In a modification, Fig. 4 (not shown), the cycle is prolonged by providing a capillary by-pass round valve 5, this delaying the build-up of receiver pressure and a by-pass is also provided between the compressor and the receiver so that, during charging of the evaporator with refrigerant, some hot gas can also pass through valve 5. It is stated that valve 5 may respond to receiver temperature or to condenser temperature or pressure. If the system works under constant thermal load, the valve may be time controlled.