摘要 |
A closed loop refrigeration system such as an air source heat pump includes a hermetic screw compressor and a helical screw rotary expander connected to an electric induction drive motor. The closed loop refrigeration circuit permits an air source evaporator to constitute a heat source for supplying vaporized refrigerant to the compressor and expander, while both are mechanically coupled to the electric induction drive motor and with both driven as compression units. The air source evaporator feeds to slide valve controlled inlet ports of both the compressor and expander. Compressed vapor from both units passes to condenser coil(s) such as heating condensers to increase the system capacity under this mode.
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