| 摘要 |
<p>An air source heat pump system includes in a primary refrigeration circuit a hermetic screw compressor 14 and a helical screw rotary expander 20 selectively clutchable to the permanently coupled helical screw compressor and electric induction drive motor 16. A solar/reclaim evaporator 62 alternately functions as an expander boiler to feed refrigerant vapor to the compressor injection slide valve 28 or to the feed port 53 of the helical rotary screw expander to cause the expander 20 to drive the compressor 14 under compressor load or to drive the electric induction motor 16 as a generator with the compressor unloaded. The solar/reclaim evaporator and expander boiler may be selectively fluid connected to the injection slide valve 28 or to the suction port 27 of the compressor. The hydronic system heating condenser 56 and water chilling evaporator coil 64 may form basic input and rejection heat exchangers to cascaded building zone heat pumps 146, 148. Additional heat input to the primary circuit may be provided by a fossil fueled combustion heater 154 feeding through the expander 20 to the hydronic system heating condenser 56.</p> |
