Heat exchanger

A heat exchanger, which is an evaporator in which a plurality of plate members are stacked with each other to define a refrigerant passage and a fluid passage, a refrigerant flowing through the refrigerant passage and a fluid flowing through the fluid passage exchanging heat with each other, the heat exchanger comprising:

• an inner fin arranged in the refrigerant passage, wherein
• the inner fin has a plurality of side wall portions formed to extend in a predetermined direction and arranged in parallel with each other,
• a gap formed between the side wall portions facing each other is a passage portion through which the refrigerant flows,
• each of the side wall portions has a plurality of openings arranged in the predetermined direction,
• a part of the side wall portion located between the openings adjacent to each other has an inclined surface inclined with respect to the predetermined direction,
• one end portion of the refrigerant passage in the predetermined direction has an inflow port through which the refrigerant flows into the refrigerant passage,
• the other end portion of the refrigerant passage in the predetermined direction has a discharge port through which the refrigerant flows out of the refrigerant passage,
• a part of the side wall portion located between the inflow port and a central portion in the predetermined direction has only an inclined surface that is inclined so as to change a flow direction of the refrigerant in a direction away from the discharge port, the part of the side wall portion extends continuously between the inflow port and the central portion,
• a part of the side wall portion located between the discharge port and the central portion in the predetermined direction has only an inclined surface that is inclined so as to change the flow direction of the refrigerant toward the discharge port, the part of the side wall portion extends continuously between the discharge port and the central portion,
• the inflow port and the discharge port are formed at two diagonal corners through the plate member, respectively,
• a width of the inflow port and a width of the discharge port are shorter than a width of the refrigerant passage,
• the inner fin is formed in a wavy shape and has a connecting portion connecting the side wall portions adjacent to each other,
• the opening and the inclined surface are not formed in the connecting portion,
• the opening and the inclined surface are formed only in the side wall portion,
• the connecting portion has a curved shape,
• the refrigerant is changed in phase from a liquid phase or a two-phase refrigerant, in which a liquid-phase refrigerant and a gas-phase refrigerant are mixed, to a gas phase,
• the inclined surface located adjacent to one of the two diagonal corners where the inflow port is formed is oriented such that the refrigerant flowing into the refrigerant passage from the inflow port flows along the inclined surface away from the discharge port located at the other of the two diagonal corners, and
• the inclined surface located adjacent to the discharge port is oriented such that the refrigerant flows along the inclined surface toward the discharge port.