Patent ID: 8113270

Claim:
A parallel flow heat exchanger arrangement for a heat pump comprising: a header defining in a cooling mode an inlet header, said inlet header having an inlet opening for conducting the flow of fluid into said inlet header and a plurality of outlet openings for conducting the flow of fluid from said inlet header; a plurality of channels aligned in a substantially parallel relationship and fluidly connected to said plurality of outlet openings for conducting the flow of fluid from said inlet header; a tube disposed within said inlet header and being fluidly connected at an inlet end to said inlet opening, said tube extending substantially the length of said inlet header and a having a plurality of openings formed therein for conducting the flow of refrigerant from said tube to said inlet header; and, a bi-flow piston assembly disposed at the inlet end of said tube, said piston assembly having a floating piston being adapted to selectively operate in response to the flow of refrigerant in a first position in a cooling mode condition to expand liquid refrigerant to a two-phase condition prior to entering said tube or in a second position in a heating mode condition to permit the flow of refrigerant directly from said header to said piston assembly without passing through said tube.