| 摘要 |
A pump 10 for a refrigeration system 100, which comprises two chambers 12a, 12b, each connected to an inlet line 20 and an outlet line 24. First valves 30a, 32a and second valves 30b, 32b bring the first chamber 12a and the second chamber 12b respectively in fluid communication with gas at a pressure comparable to pressure in the inlet line or with gas at a pressure comparable to pressure in the outlet line. Pressure equalisation means, e.g. a valve 34, selectively equalises fluid pressure in the two chambers. The valves 30a, 32a, 30b and 32b may be actuated by a controller responsive to signals from level sensors, so that the two chambers are alternately filled and emptied. The pressure in the chambers is preferably equalised before the filling and emptying modes are switched between them. An energy recovery apparatus is also claimed, comprising a turbine 112 mounted between the compressor 104 and the condenser 106 of the refrigeration system and a pump as described above. The pump is preferably connected between the condenser and the metering device 108. Gas is routed to valves 30a, 30b and 32a, 32b from points upstream and downstream of the turbine respectively. |
