Heat exchanger

Abstract

Air passages 18 are formed between surfaces of a plurality of heat transfer plates 12 laid together. A plurality of rib sections 14 extending orthogonal to the air flowing direction A are formed on a surface of the heat transfer plate 12 and projected into the air passage 18. By shifting the positions of the rib sections 14 to each other in the air flow direction, coolant passages 15, 16 are formed inside the plurality of rib sections 14. Between the plurality of rib sections 14, fin sections 17 are formed integral with the heat transfer plate 12 and projected from the plate surface. The fin section 17 has a protruded shape formed by pressing and having a cut portion partially cut a plate thickness of the heat transfer plate 2.

1 . A heat exchanger wherein 
 a plurality of heat transfer plates forming plate surfaces extending in the flowing direction (A) of external fluid are stacked together,    a gap is provided between said plate surfaces of said adjacent heat transfer plates to form an external passage through which said external fluid flows,    a plurality of rib sections extending orthogonal to the flowing direction A of said external fluid are projected from said plate surfaces into said external passage to be integral with said heat transfer plates,    by shifting positions of the plurality of rib sections in one of said adjacent heat transfer plates relative to positions of the plurality of rib sections in the other of said adjacent heat transfer plates as seen in the flowing direction A of said external fluid, said external passage is formed in a meandering manner,    the plurality of rib sections form an internal passage inside thereof, through which flows internal fluid,    fin sections are projected from said plate surfaces at positions between the adjacent rib sections to be integral with the heat transfer plate, and    said fin section is press-formed so as to protrude a cut portion partially cut a plate thickness of said heat transfer plate.    
   
   
       2 . A heat exchanger as defined by  claim 1 , wherein said heat transfer plates are combined to form pairs, and said rib sections and said fin sections are formed integral with said pair of heat transfer plates, and 
 the pair of heat transfer plates are fixed together to form said internal passage inside the plurality of rib sections.    
   
   
       3 . A heat exchanger as defined by  claim 2 , wherein positions in the pair of heat transfer plates at which said rib sections are formed are shifted in the flow direction A of the external fluid, and 
 said internal passage is formed by said rib sections formed in one of the pair of heat transfer plates and a plate surface of the other.    
   
   
       4 . A heat exchanger as defined by  claim 2 , wherein said rib sections are formed in said pair of heat transfer plates at the same positions as seen in the flowing direction A of said external fluid, and 
 said internal passages are formed by the combination of said rib sections formed in said pair of heat transfer plates, respectively.    
   
   
       5 . A heat exchanger as defined by  claim 1 , wherein said heat transfer plate is constituted by a single extrusion-formed plate material, 
 said rib sections are formed by extrusion-forming a tubular-shaped portion on said single extrusion-formed plate material, and    said fin sections are formed integral with said single extrusion-formed plate material to be projected from a plate surface of said single extrusion-formed plate material.    
   
   
       6 . A heat exchanger as defined by  claim 1 , wherein said heat transfer plate has a base plate section having a flat surface between the adjacent rib sections, and 
 said fin section is formed in said base plate section.    
   
   
       7 . A heat exchanger as defined by  claim 1 , wherein a width (Fw) in the flowing direction (A) of said external fluid of said fin section is 5 mm or less.  
   
   
       8 . A heat exchanger as defined by  claim 1 , wherein said fin section is a slit fin having an offset wall surface apart from a plate surface of said heat transfer plate at a predetermined gap, wherein said offset wall surface are coupled to a plate surface of said heat transfer plate at two positions.  
   
   
       9 . A heat exchanger as defined by  claim 8  wherein, when a gap between positions on the pair of heat transfer plates opposed to each other to define said external passage, at which positions are formed said slit fins, is defined as L, and a projected height of said offset wall surface from a plate surface of said heat transfer plate is defined as Fha, the following relationship is satisfied:  
         Fha≦ ½ L.    
   
   
       10 . A heat exchanger as defined by  claim 8 , wherein a cross-sectional shape of said rib section has a curved surface projected from the surface of said heat transfer plate, which is generally semicircular, 
 said slit fin is located at a position directly on downstream side from said external fluid relative to said rib section, and    said offset wall surface is inclined in the same direction as the inclination of the downstream side curved surface in the generally semicircular curved surface of said rib section.    
   
   
       11 . A heat exchanger as defined by  claim 8 , wherein the cross-sectional shape of said rib section is such that it has a curved surface protruded semi-circularly from a surface of said heat transfer plate, 
 said slit fin is disposed adjacent to said rib section at a position directly on the upstream side of said external fluid, and    said offset wall surface is inclined in the same direction as the inclination of the upstream side curved surface in a generally semicircular curved surface of said rib section.    
   
   
       12 . A heat exchanger as defined by  claim 8 , wherein said slit fin is disposed opposite to a front of said rib section while interposing said external passage, and said offset wall surface is formed to be parallel to a flat surface of said heat transfer plate.  
   
   
       13 . A heat exchanger as defined by  claim 8 , wherein said external fluid is air and said internal fluid is a coolant for cooling said air, wherein said heat exchanger is constituted as a cooling heat exchanger generating condensation water on the surface of said heat transfer plate, and 
 a gap (Q 1 , Q 2 ) between said offset wall surface and the surface of said heat transfer plate is 0.3 mm or more.    
   
   
       14 . A heat exchanger as defined by  claim 1 , wherein said fin section is a protruded fin having a predetermined angle relative to the surface of said heat transfer plate.  
   
   
       15 . A heat exchanger as defined by  claim 14 , wherein said protruded fin is triangular.  
   
   
       16 . A heat exchanger as defined by  claim 15 , wherein said triangular protruded fin is inclined to the flowing direction (A) of said external fluid at an angle from 15° to 45°.  
   
   
       17 . A heat exchanger as defined by  claim 14 , wherein said protruded fin is rectangular.  
   
   
       18 . A heat exchanger as defined by  claim 14 , wherein the inclination angle of said protruded fin relative to the flowing direction (A) of said external fluid is determined in a small angle range from − 30 ° to +30° so that a surface of the protruded fin follows the flow direction (A) of said external fluid.  
   
   
       19 . A heat exchanger as defined by  claim 14 , wherein said external fluid is air and internal fluid for cooling said air flows through said internal passage, 
 said heat transfer plate is disposed so that the longitudinal direction of said rib section coincides with the upward/downward direction, and    an inclination angle of said protruded fin is in a range from 60° to 120° relative to the flowing direction (A) of said external fluid so that a surface of said protruded fin follows the longitudinal direction of said rib section.    
   
   
       20 . A heat exchanger as defined by  claim 1 , wherein said internal passage has an upstream side internal passage disposed on the upstream side in the flow direction (A) of said external fluid and a downstream side internal passage disposed on the downstream side in the flowing direction (A) of said external fluid, 
 said upstream side internal passage and said downstream side internal passage are respectively sectioned vertically to the flowing direction (A) of said external fluid into a plurality of areas (X, Y), and    passages connected in parallel to each other are constituted between the plurality of areas (X, Y) of said upstream side internal passages and the plurality of areas (X, Y) of said downstream side internal passages.    
   
   
       21 . A heat exchanger as defined by  claim 20 , wherein said downstream side internal passage is an inlet side passage for said internal fluid, and said upstream side internal passage is an exit side passage for said internal fluid.  
   
   
       22 . A heat exchanger as defined by  claim 20 , wherein said parallel passages couple the plurality of areas (X, Y) in said upstream side internal passage and the plurality of areas (X, Y) in said downstream side internal passage to each other in an X pattern.