Heat exchanger and refrigeration cycle apparatus

Abstract

A heat exchanger that exchanges heat between a first fluid and a second fluid, includes: a first flow path through which the first fluid flows; a second flow path through which the second fluid flows; a first wall between the first flow path and the second flow path; and a second wall between the first wall and the second flow path. The first fluid flows through the first flow path in a direction intersecting a stacking direction that is a direction in which the first wall and the second wall are stacked. The second fluid flows through the second flow path in a direction intersecting the stacking direction.

What is claimed is: 
     
         1 . A heat exchanger that exchanges heat between a first fluid and a second fluid, the heat exchanger comprising:
 a first flow path through which the first fluid flows;   a second flow path through which the second fluid flows;   a first wall between the first flow path and the second flow path; and   a second wall between the first wall and the second flow path, wherein   the first fluid flows through the first flow path in a direction intersecting a stacking direction that is a direction in which the first wall and the second wall are stacked,   the second fluid flows through the second flow path in a direction intersecting the stacking direction, and   either or both of:
 the first wall comprises: a first flat portion; and first protrusions protruding in the stacking direction, and distal ends of the first protrusions contact the second wall, and 
 the second wall comprises: a second flat portion; and second protrusions protruding in the stacking direction, and distal ends of the second protrusions contact the first wall. 
   
     
     
         2 . The heat exchanger according to  claim 1 , further comprising:
 a first plate in which the first flow path is disposed; and   a second plate in which the second flow path and the second wall are disposed, wherein   the second flow path and the second wall are disposed in a plate thickness direction of the second plate.   
     
     
         3 . The heat exchanger according to  claim 2 , further comprising:
 a first partition wall comprising the first wall, wherein   the first partition wall is disposed between the first plate and the second plate, and either or both of:
 the first partition wall comprises: the first flat portion; and the first protrusions, and the distal ends of the first protrusions contact the second wall, and 
 the second wall comprises: the second flat portion; and the second protrusions, and the distal ends of the second protrusions contact the first partition wall. 
   
     
     
         4 . The heat exchanger according to  claim 3 , further comprising a liquid between the first partition wall and the second wall. 
     
     
         5 . The heat exchanger according to  claim 4 , further comprising a seal that covers between the first partition wall and the second wall from a periphery in the stacking direction. 
     
     
         6 . The heat exchanger according to  claim 3 , wherein
 either or both of:
 the first partition wall comprises a first concave portion recessed in the stacking direction with respect to the first flat portion, and the distal ends of the first protrusions are disposed toward the second wall in the stacking direction with respect to the first concave portion, and 
 the second wall comprises a second concave portion recessed in the stacking direction with respect to the second flat portion, and the distal ends of the second protrusions are disposed toward the first partition wall in the stacking direction with respect to the second concave portion. 
   
     
     
         7 . The heat exchanger according to  claim 3 , wherein
 the second wall comprises a second region in which the second protrusions are disposed,   the first partition wall comprises a first region facing the second region when viewed along the stacking direction, and   the second region has a larger surface area than the first region.   
     
     
         8 . The heat exchanger according to  claim 3 , wherein
 the first partition wall has a first opening,   the second wall has a second opening at a position overlapping the first opening in the stacking direction,   the first opening and the second opening allow the first fluid or the second fluid to pass in the stacking direction, and   the first partition wall and the second wall include a portion where the first flat portion around the first opening is in surface contact with the second flat portion around the second opening.   
     
     
         9 . The heat exchanger according to  claim 2 , wherein
 the first plate includes the first wall, and   the first flow path and the first wall are disposed in a plate thickness direction of the first plate.   
     
     
         10 . The heat exchanger according to  claim 1 , comprising:
 a first plate in which the first flow path is disposed; and   a second plate in which the second flow path is disposed, wherein   the first wall is disposed between the first plate and the second plate,   the second wall is disposed between the first wall and the second plate, and either or both of:
 the first flat portion and the first protrusions are disposed in the first wall, and 
 the second flat portion and the second protrusions are disposed in the second wall. 
   
     
     
         11 . The heat exchanger according to  claim 10 , comprising a liquid between the first wall and the second wall. 
     
     
         12 . The heat exchanger according to  claim 11 , further comprising a seal that covers between the first wall and the second wall from a periphery in the stacking direction. 
     
     
         13 . The heat exchanger according to  claim 10 , wherein
 either or both of:
 the first wall comprises a first concave portion recessed in the stacking direction with respect to the first flat portion, and the distal ends of the first protrusions are disposed toward the second wall in the stacking direction with respect to the first concave portion, and 
 the second wall comprise a second concave portion recessed in the stacking direction with respect to the second flat portion, and the distal ends of the second protrusions are disposed toward the first wall in the stacking direction with respect to the second concave portion. 
   
     
     
         14 . The heat exchanger according to  claim 10 , wherein
 the second wall comprises a second region in which the second protrusions are disposed,   the first wall comprises a first region facing the second region when viewed along the stacking direction, and   the second region has a larger surface area than the first region.   
     
     
         15 . The heat exchanger according to  claim 10 , wherein
 the first wall has a first opening,   the second wall has a second opening at a position overlapping the first opening in the stacking direction,   the first opening and the second opening allow the first fluid or the second fluid to pass in the stacking direction, and   the first wall and the second wall include a portion where the first flat portion around the first opening is in surface contact with the second flat portion around the second opening.   
     
     
         16 . The heat exchanger according to  claim 1 , wherein the second fluid is water. 
     
     
         17 . The heat exchanger according to  claim 1 , wherein the first fluid is a refrigerant with flammability. 
     
     
         18 . A refrigeration cycle apparatus, comprising:
 a refrigerant circuit that includes the heat exchanger according to  claim 1  and through which the first fluid flows.