Abstract:
Disclosed is a unitary heat pump air conditioner (HPAC) system having a refrigerant diversion loop configured to supply sufficient heat to defrost an external heat exchanger while not materially affecting the supply of heat to the passenger compartment of a vehicle. The HPAC system includes a refrigerant loop configured to pump heat from a cold coolant loop that scavenges heat from the external heat exchanger to a hot coolant loop that supplies heat to the passenger compartment. The refrigerant loop includes a condenser in thermal communication with the hot coolant loop, evaporator in thermal communication with the cold coolant loop, and a compressor to cycle the refrigerant through the refrigerant loop. The refrigerant loop further includes means to selectively divert at least a portion of the hot compressed refrigerant exiting the compressor directly to the evaporator to heat the cold coolant loop sufficient to defrost the external heat exchanger.
Abstract:
A plate-type heat exchanger having a first heat exchanger portion configured to receive a refrigerant flow and a hot side coolant flow having a lower temperature than the refrigerant flow, a second heat exchanger portion configured to receive the refrigerant flow exiting from the first heat exchanger portion and a cold side coolant flow having a higher temperature than the refrigerant flow exiting from the first heat exchanger portion, and an internal heat exchanger portion sandwiched between the first heat exchanger portion and the second heat exchanger portion. The refrigerant flow through the plate type heat exchanger is in non-contact thermal communication with the hot side coolant flow and the cold side coolant flow. The cold side coolant flow transfers heat energy to the refrigerant, which in turn transfer that heat energy to the hot side coolant flow.