VARIABLE SPEED LIQUID REFRIGERANT PUMP

摘要

The invention entails the use of a positive displacement pump (41) magnetically coupled to a drive motor (42) located in a conduit arrangement (60) which is parallel to the liquid line (22) of the refrigeration system as in Fig. 5. This parallel conduit arrangement (60) also includes a pressure regulating valve (45) that will regulate the amount of pressure added to the liquid line (22) by the parallel pump and piping arrangement (60). In addition, a check valve (47) is located in the liquid line (22) to maintain the pressure differential added to the liquid line. This parallel piping arrangement (60) is desirable in order to allow a constant predetermined pressure to be added to the liquid line regardless of variations in flow rate of the liquid refrigerant. The present invention involves the use of a controlled variable speed drive on the pump meter so the flow rate through the pump will more closely match the variable system flow.