A unitary heat pump air conditioner having a compressed vapor diversion loop

Abstract

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).

Description

[0001] Cross references to related applications [0002] This application claims the priority of U.S. Provisional Application No. 61 / 777,677 filed on March 12, 2013, and the entire content is incorporated here. [0003] This application is also a partial continuation application of the International Application No. PCT / US2012 / 025419 filed on February 16, 2012, and claims the priority of U.S. Provisional Application No. 61 / 443,774 filed on February 17, 2011. [0004] This application is also a partial continuation application of U.S. Patent Application No. 13 / 396,211 filed on February 14, 2012, and claims the priority of U.S. Provisional Application No. 61 / 443,774 filed on February 17, 2011. [0005] International Application No. PCT / US2012 / 025419, U.S. Patent Application No. 13 / 396,211, and U.S. Provisional Application No. 61 / 443,774 are incorporated herein by reference in their entirety. Technical field [0006] The present disclosure relates to heating and air conditioning systems for...

AI Technical Summary

Problems solved by technology

[0009] Since the low pressure side of the system when used in air conditioning mode becomes the high pressure side when used in heat pump mode, one disadvantage of running the air conditioning system in heat pump mode is the added complexity of the system as it is required to pass through the use of thicker metering tubes and accessories to strengthen the refrigerant piping facilities of the whole system

Another known disadvantage of running the system in heat pump mode is that at colder temperatures, such as when the surface temperature of the condenser drops below 32°F, any water vapor that condenses on the surface of the condenser will freeze, thus making the system less effective and may even damage the condenser

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