Heat exchanger

Abstract

A heat exchanger causes heat exchange between water and a refrigerant. The heat exchanger includes a first flow path through which the water flows, and a second flow path through which the refrigerant flows. A fragile portion is formed by any one of members forming the first flow path other than a partition wall partitioning the first flow path and the second flow path or any one of joining portions where members forming the first flow path are joined to each other. The fragile portion has a lower strength than the other members forming the first flow path.

1 . A heat exchanger configured to cause heat exchange between water and a refrigerant, the heat exchanger comprising:
 a first flow path through which the water flows; and   a second flow path through which the refrigerant flows,   a fragile portion being formed by
 any one of members forming the first flow path other than a partition wall partitioning the first flow path and the second flow path or 
 any one of joining portions where members forming the first flow path are joined to each other, and 
   the fragile portion having a lower strength than the other members forming the first flow path.   
     
     
         2 . The heat exchanger according to  claim 1 , wherein
 the first flow path is formed using
 two partition walls, 
 inner fins stacked between the two partition walls and each having a corrugated cross section, and 
 separation members disposed at end edges of the two partition walls and each separating the two partition walls from each other. 
   
     
     
         3 . The heat exchanger according to  claim 2 , wherein
 the fragile portion is the inner fins.   
     
     
         4 . The heat exchanger according to  claim 3 , wherein
 tw/Lw<tR/hw, with
 tw representing a thickness of the inner fin, 
 Lw representing an interval between top portions of the inner fin in contact with the same partition wall, 
 tR representing a thickness of the partition wall, and 
 hw representing a height of the inner fin in a stacking direction. 
   
     
     
         5 . The heat exchanger according to  claim 2 , wherein
 the fragile portion is the separation members.   
     
     
         6 . The heat exchanger according to  claim 5 , wherein
 ((Lsp+tw)/Lw)<tR/hw, with
 Lsp representing a width of the separation member in plan view, 
 tw representing a thickness of the inner fin, 
 Lw representing an interval between top portions of the inner fin in contact with the same partition wall, 
 tR representing a thickness of the partition wall, and 
 hw representing a height of the inner fin in a stacking direction. 
   
     
     
         7 . The heat exchanger according to  claim 1 , wherein
 the first flow path is formed using
 two partition walls, 
 inner fins stacked between the two partition walls and each having a corrugated cross section, and 
 separation members disposed at end edges of the two partition walls and each separating the two partition walls from each other, 
   
       the heat exchanger further comprising:
 a first joining portion where the partition wall and top portions of the inner fin are joined; and 
 a second joining portion where the partition wall and the separation member are joined. 
 
     
     
         8 . The heat exchanger according to  claim 7 , wherein
 the fragile portion is the first joining portion.   
     
     
         9 . The heat exchanger according to  claim 8 , wherein
 joining in the first joining portion is joined by brazing, and   0.35×bw1/(2×Lw)<tR/hw, with
 bw1 representing a width of the first joining portion, 
 Lw representing an interval between the top portions of the inner fin in contact with the same partition wall, 
 tR representing a thickness of the partition wall, and 
 hW representing a height of the inner fin in a stacking direction. 
   
     
     
         10 . The heat exchanger according to  claim 8 , wherein
 joining in the first joining portion is implemented by diffusion joining, and   bw1/(2×Lw)<tR/hw, with
 bw1 representing a width of the first joining portion, 
 Lw representing an interval between the top portions of the inner fin in contact with the same partition wall, 
 tR representing a thickness of the partition wall, and 
 hW representing a height of the inner fin in a stacking direction. 
   
     
     
         11 . The heat exchanger according to  claim 7 , wherein
 the fragile portion is the second joining portion.   
     
     
         12 . The heat exchanger according to  claim 11 , wherein
 joining in the second joining portion is joined by brazing, and   0.35× (2×bsp2+bw1)/Lw<2×tR/hw, with
 bsp2 representing a width of the second joining portion, 
 bw1 representing a width of the first joining portion, 
 Lw representing an interval between the top portions of the inner fin in contact with the same partition wall, 
 tR representing a thickness of the partition wall, and 
 hW representing a height of the inner fin in a stacking direction. 
   
     
     
         13 . The heat exchanger according to  claim 11 , wherein
 joining in the second joining portion is implemented by diffusion joining, and   (2× bsp2+bw1)/Lw<2×tR/hw, with
 bsp2 representing a width of the second joining portion, 
 bw1 representing a width of the first joining portion, 
 Lw representing an interval between the top portions of the inner fin in contact with the same partition wall, 
 tR representing a thickness of the partition wall, and 
 hW representing a height of the inner fin in a stacking direction. 
   
     
     
         14 . The heat exchanger according to  claim 1 , wherein
 the first flow path is formed using two heat transfer plates stacked on each other and each having a corrugated cross section, and   
       the heat exchanger further comprising:
 a third joining portion where top portions of the two heat transfer plates are joined; and 
 a fourth joining portion where end edges of the two heat transfer plates are joined. 
 
     
     
         15 . The heat exchanger according to  claim 14 , wherein
 the fragile portion is the third joining portion.   
     
     
         16 . The heat exchanger according to  claim 15 , wherein
 the third joining portion is joined by brazing, and   0.35×bw3<2×t, with
 bw3 presenting a width of the third joining portion as viewed along a normal direction, and 
 t representing a thickness of the heat transfer plate. 
   
     
     
         17 . The heat exchanger according to  claim 15 , wherein
 the third joining portion is implemented by diffusion joining, and   bw3<2×t, with
 bw3 presenting a width of the third joining portion as viewed along a normal direction, and 
 t representing a thickness of the heat transfer plate. 
   
     
     
         18 . The heat exchanger according to  claim 14 , wherein
 the fragile portion is the fourth joining portion.   
     
     
         19 . The heat exchanger according to  claim 18 , wherein
 the fourth joining portion is joined by brazing, and   0.35×(bsp4+bw3/2)<2×t, with
 bsp4 representing a width of the fourth joining portion as viewed along a normal direction, 
 bw3 presenting a width of the third joining portion as viewed along the normal direction, and 
 t representing a thickness of the heat transfer plate. 
   
     
     
         20 . The heat exchanger according to  claim 18 , wherein
 the fourth joining portion is implemented by diffusion joining, and   (bsp4+bw3/2)<2×t, with
 bsp4 representing a width of the fourth joining portion as viewed along a normal direction, 
 bw3 presenting a width of the third joining portion as viewed along the normal direction, and 
 t representing a thickness of the heat transfer plate. 
   
     
     
         21 . The heat exchanger according to  claim 1 , further comprising:
 a first heat transfer plate having the first flow path formed therein; and   a second heat transfer plate having the second flow path formed therein,   the fragile portion being the first heat transfer plate.   
     
     
         22 . The heat exchanger according to  claim 21 , wherein
 the first heat transfer plate is formed by stacking two plate-shaped members in which grooves forming the first flow path are formed, and   the fragile portion is a portion where the two plate-shaped members are joined.   
     
     
         23 . The heat exchanger according to  claim 1 , wherein
 the refrigerant is flammable or toxic.   
     
     
         24 . The heat exchanger according to  claim 1 , wherein
 the fragile portion is formed with such a strength that the fragile portion breaks when the water freezes.