AIR SOURCE HEAT PUMP WITH MULTIPLE SLIDE ROTARY SCREW COMPRESSOR/EXPANDER

摘要

ABSTRACTAn air source heat pump system includes in aprimary refrigeration circuit a hermetic screw compressor14 and a helical screw rotary expander 20 selectivelyclutchable to the permanently coupled helical screwcompressor and electric induction drive motor 16. Asolar/reclaim evaporator 62 alternately functions as anexpander boiler to feed refrigerant vapor to the compressorinjection slide valve 28 or to the feed port 53 of thehelical rotary screw expander to cause the expander 20 todrive the compressor 14 under compressor load or to drivethe electric induction motor 16 as a generator with thecompressor unloaded. The solar/reclaim evaporator andexpander boiler may be selectively fluid connected to theinjection slide valve 28 or to the suction port 27 of thecompressor. The hydronic system heating condenser 56 andwater chilling evaporator coil 64 may form basic input andrejection heat exchangers to cascaded building zone heatpumps 146, 148. Additional heat input to the primarycircuit may be provided by a fossil fueled combustionheater 154 feeding through the expander 20 to the hydronicsystem heating condenser 56.