| 摘要 |
<p>915,598. Refrigerating. GARRETT CORPORATION. Dec. 9, 1960 [Dec. 14, 1959], No. 42525/60. Class 29. In a closed cycle refrigeration system having a compressor 1 of a type liable to surging, a condenser 2, an evaporator 4, by-passing means 28, 29 for hot gas leaving the compressor to flow to the low pressure side of the closed circuit to prevent surging, a valve 15 to control and throttle the liquid refrigerant passing from the liquid receiver 3 to the evaporator 4 and to control simultaneously but in opposite sense the flow of hot gas through the by-pass, the valve is actuated by a linear actuator 16 driven by an electric motor 17 controlled by controller 18, the error signal to the controller being derived by a temperature responsive thermistor sensor 24. As shown, by-pass pipe 29 leads to the evaporator inlet, but in a modification (Fig. 1A, not shown), pipe 29 leads to the evaporator outlet, liquid refrigerant being fed through a restriction from receiver 3 to pipe 28 to prevent too high a gas temperature in the compressor inlet. The liquid refrigerant is fed to the evaporator inlet through distributer tube 27. The heating effect due to the hot gas may be greater than the cooling effect of the liquid refrigerant so that the system can act as a heater as well as a cooler. The valve assembly may have a position in which, upon stopping of the compressor, liquid refrigerant in the evaporator strains back to the receiver. Fig. 2 shows an embodiment of the valve 15, comprising casing 31 having liquid inlet and outlet passages 32 and 33 respectively and gas inlet and outlet passages 34 and 35 respectively. The moving member 38 of the valve comprises a spindle for portions of varying diameter extending through sleeves 37 and 42 and has a piston 44 and a reduced portion 45 which control the area of the throttling port 39. The lower end of the valve member 38 carries a cupshaped piston 46 controlling the area of the gas throttling ports 43 and hence controls the flow of gas through the valve. Figs. 5-8 and Fig. 9 (not shown) show other embodiments of a valve, comprising a rotary member within the casing, having a liquid groove and a gas groove on the periphery of the rotating member, these grooves arranged to communicate with the liquid and gas inlet and outlet passages and perform a similar operation to the valve shown in Fig. 2. Specifications 674,687, 686,607, 860,227 and U.S.A. Specifications 2,328,897 and 2,482,464 are referred to.</p> |
