Heat exchanger

Abstract

The heat exchanger includes core portions overlapped with each other in the flow direction of the air and such that the heat transfer medium flows continuously, the core portions each including the upper header tank to which the heat transfer medium is supplied, the lower header tank arranged below the upper header tank, and tubes configured to connected the upper header tank and the lower header tank. The tubes perform heat exchange between the heat transfer medium flowing inside the tubes and the air flowing around the tubes. A communication passage allows communication between the lower header tank of the first core portion and the upper header tank of the second core portion and allows the heat transfer medium to flow from the lower header tank to the upper header tank. The second core portion is overlapped with the first core portion in the air flow direction.

1 . A heat exchanger configured to heat air by condensing a heat transfer medium undergoing a phase change between a liquid phase and a gaseous phase, the heat exchanger comprising
 a plurality of core portions provided such that the plurality of core portions are overlapped with each other in a flow direction of the air and such that the heat transfer medium flows continuously, the core portions each comprising: an upper header tank to which the heat transfer medium is supplied; a lower header tank arranged below the upper header tank; and a plurality of tubes configured to connect the upper header tank and the lower header tank, the plurality of tubes being configured to perform heat exchange between the heat transfer medium flowing inside the tubes and the air flowing around the tubes, and   a communication passage configured to allow communication between the lower header tank of a first core portion of the core portions and the upper header tank of a second core portion of the core portions and to allow the heat transfer medium to flow from the lower header tank to the upper header tank, the second core portion being arranged so as to be overlapped with the first core portion in the flow direction of the air.   
     
     
         2 . The heat exchanger according to  claim 1 , wherein
 the upper header tank of the first core portion has a heat transfer medium inlet, through which the heat transfer medium enters, on a first end portion, and the lower header tank of the second core portion has a heat transfer medium outlet, through which the heat transfer medium flows out, on a first end portion, and   the communication passage allows communication between a second end portion of the lower header tank of the first core portion and a second end portion of the upper header tank of the second core portion.   
     
     
         3 . The heat exchanger according to  claim 1 , wherein
 the communication passage is formed of: a lower connector connected to the lower header tank of the first core portion so as to be communicable; an upper connector connected to the upper header tank of the second core portion so as to be communicable; and a tube member connected to connection holes of the lower connector and the upper connector so as to allow communication between the lower connector and the upper connector.   
     
     
         4 . The heat exchanger according to  claim 3 , wherein
 in a state in which the lower connector is connected to the corresponding lower header tank and the upper connector is connected to the corresponding upper header tank, the connection hole of the lower connector and the connection hole of the upper connector, to which the tube member is connected, face with each other and open in a direction same as an extending direction of the tubes.   
     
     
         5 . The heat exchanger according to  claim 4 , wherein
 the lower connector and the upper connector are formed of a same member.   
     
     
         6 . The heat exchanger according to  claim 5 , wherein
 the member is formed of a block, the block having, in a surface, a first insertion hole and a second insertion hole into which each end portion of the upper header tanks, which are arranged so as to be overlapped, or each end portion of the lower header tanks, which are arranged so as to be overlapped, can be inserted, respectively, and the block having the connection hole in communication with the first insertion hole in an intersecting surface extending in a direction intersecting with an extending direction of the surface, the connection hole being arranged at a midpoint between a center line extending through a center of the first insertion hole and a center line extending through a center of the second insertion hole.