A UNITARY HEAT PUMP AIR CONDITIONER HAVING A COMPRESSED VAPOR DIVERSION LOOP

摘要

Disclosed is a unitary heat pump air conditioner (HPAC) system (10) having a refrigerant diversion loop (49) configured to supply sufficient heat to defrost an external heat exchanger (44) while not materially affecting the supply of heat to the passenger compartment of a vehicle. The HPAC system (10) includes a refrigerant loop (12) configured to pump heat from a cold coolant loop (14) that scavenges heat from the external heat exchanger (44) to a hot coolant loop (16) that supplies heat to the passenger compartment. The refrigerant loop (12) includes a condenser (18) in thermal communication with the hot coolant loop (16), evaporator (22) in thermal communication with the cold coolant loop (14), and a compressor (24) to cycle the refrigerant through the refrigerant loop (12). The refrigerant loop (12) further includes means to selectively divert at least a portion of the hot compressed refrigerant exiting the compressor (24) directly to the evaporator (22) to heat the cold coolant loop (14) sufficient to defrost the external heat exchanger (44).