TUBE INSET AND BI-FLOW ARRANGEMENT FOR A HEADER OF A HEAT PUMP

摘要

An inlet header (22) of a microchannel heat pump heat exchanger has a tube (34) disposed therein and extending substantially the length of the inlet header (22), with the tube (34) having a plurality of openings (36) therein. During cooling mode operation, refrigerant is caused to flow into an open end of the tube (34) and along its length to thereby flow from the plurality of openings (36) into the inlet header (22) prior to entering the microchannels (24) to thereby provide a uniform flow of two-phase refrigerant thereto. A bi-flow expansion device (41) placed at the inlet end of the tube (34) allows for the expansion of liquid refrigerant into the tube (34) during periods in which the heat exchanger operates as an evaporator and allows the refrigerant to flow directly from the header (22) and around the tube (34) during periods in which the heat exchanger operates as a condenser coil.