Patent ID: 7726387

Claim:
A heat exchanger comprising: a refrigerant inlet header having a refrigerant inlet and positioned in a downstream side of a direction of air flow; a refrigerant outlet header positioned in an upstream side of the direction of air flow and having a refrigerant outlet; and a refrigerant circulating passage for causing the inlet header to communicate with the outlet header therethrough, the circulating passage comprising at least two intermediate headers and a plurality of heat exchange tubes for causing the inlet header and the outlet header to communicate with all the intermediate headers therethrough, the intermediate headers including a refrigerant inflow intermediate header and a refrigerant outflow intermediate header juxtaposed in an upstream-downstream direction of air flow, the inflow intermediate header and the outflow intermediate header being held in communication at one end of the inflow intermediate header, wherein a heat exchange core comprises tube groups in a plurality of rows arranged in the upstream-downstream direction, each of the tube groups comprising the plurality of heat exchange tubes arranged at a spacing, the refrigerant inlet header positioned toward one end of each of the heat exchange tubes and having joined thereto the heat exchange tubes of one tube group of at least one row, the refrigerant outlet header positioned toward said one end of each heat exchange tube and having joined thereto the heat exchange tubes of the other tube group, the refrigerant inflow intermediate header positioned toward the other end of each heat exchange tube and having jointed thereto the heat exchange tubes joined to the inlet header, and the refrigerant outflow intermediate header positioned toward said other end of each heat exchange tube and in the upstream side and having joined thereto the heat exchange tubes joined to the outlet header, wherein the outflow intermediate header is provided in interior thereof with first flow dividing control means for causing a refrigerant to dividedly flow into the heat exchange tubes joined to the outflow intermediate header uniformly, the first flow dividing control means comprises a first flow dividing control wall having a plurality of refrigerant passing holes for dividing the interior of the outflow intermediate header into first and second spaces arranged one above the other, the inflow intermediate header and the first space of the outflow intermediate header being held in communication at one end of the inflow intermediate header header, and the heat exchange tubes joined to the outflow intermediate header communicate with the second space, wherein the refrigerant passing holes formed in the first flow dividing control wall are arranged at a spacing longitudinally thereof, and the refrigerant passing holes are formed in a portion of the first flow dividing control wall to the upstream side of a midportion thereof with respect to the upstream-downstream direction.