Vapor injection system

摘要

A heat pump includes a first and second heat exchanger, a scroll compressor and a flash tank in fluid communication. The flash tank includes an inlet fluidly coupled to the heat exchangers to receive liquid refrigerant. Furthermore, the flash tank includes a first outlet fluidly coupled to the first and second heat exchangers and a second outlet fluidly coupled to the scroll compressor. The first outlet is operable to deliver sub-cooled-liquid refrigerant to the heat exchangers while the second outlet is operable to deliver vaporized refrigerant to the scroll compressor. An expansion valve is further provided and is operable to selectively open and close the inlet by a float device. The float device is operable to control an amount of liquid refrigerant disposed within the flash tank by regulating an amount of liquid refrigerant entering the flash tank via the inlet.