Plate heat exchanger

Abstract

A plate heat exchanger includes a plurality of heat transfer plates, the plurality of heat transfer plates including: a first heat transfer plate, including protrusions protruding upward, the protrusions having a top; and a second heat transfer plate stacked on the first heat transfer plate, the second heat transfer plate includes recesses recessed downward, the recesses having a bottom. The tops of the protrusions have a concave portion which is sunken downward, and at least part of the bottoms of the recesses of the second heat transfer plate is disposed in the concave portion of the tops of the protrusions of the first heat transfer plate. It is thus possible to improve the weld quality of the heat exchanger.

1 . A plate heat exchanger, comprising a plurality of heat transfer plates, the plurality of heat transfer plates comprising:
 a first heat transfer plate comprising a protrusion protruding upward, the protrusion having a top; and   a second heat transfer plate stacked on the first heat transfer plate and comprising a recess sunken downward, the recess having a bottom,   wherein a top of the protrusion has a concave portion sunken downward, and at least a part of a bottom of the recess of the second heat transfer plate is located in the concave portion at the top of the protrusion of the first heat transfer plate.   
     
     
         2 . The plate heat exchanger as claimed in  claim 1 , wherein
 the concave portion at the top of the protrusion is located in the middle of the top.   
     
     
         3 . The plate heat exchanger as claimed in  claim 1 , wherein
 the concave portion at the top of the protrusion is located on one side of the top, and the top of the protrusion is step-shaped.   
     
     
         4 . The plate heat exchanger as claimed in  claim 1 , wherein
 the concave portion at the top of the protrusion has an upward flat bottom surface.   
     
     
         5 . The plate heat exchanger as claimed in  claim 1 , wherein
 the bottom of the recess has a downward curved bottom surface or a downward flat bottom surface.   
     
     
         6 . The plate heat exchanger as claimed in  claim 1 , wherein
 a portion at the top of the protrusion other than the concave portion has at least one of a curved top surface portion and a flat top surface portion.   
     
     
         7 . The plate heat exchanger as claimed in  claim 1 , wherein
 the bottom of the recess has a concave portion sunken upward.   
     
     
         8 . The plate heat exchanger as claimed in  claim 7 , wherein
 the concave portion at the bottom of the recess is located in the middle of the bottom.   
     
     
         9 . The plate heat exchanger as claimed in  claim 8 , wherein
 a bottom portion of the concave portion at the top of the protrusion has an upward convex portion, and at least a part of the convex portion of the bottom portion of the concave portion at the top of the protrusion is located in the concave portion at the bottom of the recess.   
     
     
         10 . The plate heat exchanger as claimed in  claim 1 , wherein
 the bottom of the recess has a convex portion protruding downward, and at least a part of the convex portion at the bottom of the recess is located in the concave portion at the top of the protrusion.   
     
     
         11 . The plate heat exchanger as claimed in  claim 10 , wherein
 the concave portion at the top of the protrusion is located on one side of the top, and the top of the protrusion is step-shaped; and   the convex portion at the bottom of the recess is located on one side of the bottom of the recess, and the bottom of the recess is step-shaped.   
     
     
         12 . The plate heat exchanger as claimed in  claim 9 , wherein
 the top of the protrusion and the bottom of the recess have complementary shapes.   
     
     
         13 . The plate heat exchanger as claimed in  claim 1 , wherein
 the protrusion of the first heat transfer plate and the recess of the second heat transfer plate are located in at least a part of a heat exchange zone and/or   at least a part of an opening zone of the plate heat exchanger.   
     
     
         14 . The plate heat exchanger as claimed in  claim 1 , wherein
 the first heat transfer plate further comprises a recess sunken downward, and the second heat transfer plate further comprises a protrusion protruding upward.   
     
     
         15 . The plate heat exchanger as claimed in  claim 14 , wherein
 the plurality of heat transfer plates comprise a plurality of first heat transfer plates and a plurality of second heat transfer plates, which are stacked on top of each other, the plurality of first heat transfer plates and the plurality of second heat transfer plates being alternately arranged, and the bottom of the recess of one of every two adjacent heat transfer plates being connected to the top of the protrusion of the other of the two adjacent heat transfer plates.   
     
     
         16 . The plate heat exchanger as claimed in  claim 15 , wherein
 the top of the protrusion of the second heat transfer plate has a concave portion sunken downward, and at least a part of the bottom of the recess of the first heat transfer plate is located in the concave portion at the top of the protrusion of the second heat transfer plate.   
     
     
         17 . The plate heat exchanger as claimed in  claim 1 , wherein
 the concave portion at the top of the protrusion of the first heat transfer plate and the bottom of the recess of the second heat transfer plate are circular when viewed in the stacking direction of the first heat transfer plate and the second heat transfer plate, or   the concave portion at the top of the protrusion of the first heat transfer plate and the bottom of the recess of the second heat transfer plate are crescent-shaped when viewed in the stacking direction of the first heat transfer plate and the second heat transfer plate.   
     
     
         18 . The plate heat exchanger as claimed in  claim 16 , wherein
 the concave portion at the top of the protrusion of the first heat transfer plate is circular when viewed in the stacking direction of the first heat transfer plate and the second heat transfer plate, and the concave portion at the top of the protrusion of the second heat transfer plate is crescent-shaped when viewed in the stacking direction of the first heat transfer plate and the second heat transfer plate.   
     
     
         19 . The plate heat exchanger as claimed in  claim 1 , wherein
 the angle of inclination of at least a part of a side wall of the concave portion at the top of the protrusion of the first heat transfer plate with respect to a horizontal plane is greater than or equal to the angle of inclination of a corresponding portion of a side wall of the recess of the second heat transfer plate with respect to the horizontal plane.   
     
     
         20 . The plate heat exchanger as claimed in  claim 10 , wherein
 the angle of inclination of at least a part of a side wall of the concave portion at the top of the protrusion of the first heat transfer plate with respect to a horizontal plane is greater than or equal to the angle of inclination of a corresponding portion of a side wall of the convex portion at the bottom of the recess of the second heat transfer plate with respect to the horizontal plane.