Fin-tube heat exchanger, fin for heat exchanger, and heat pump apparatus

Abstract

A fin-tube heat exchanger 1 includes a plurality of fins 3 arrayed spaced apart from and parallel to each other so as to form gaps for allowing a first fluid to flow therethrough, and a plurality of heat transfer tubes 2 penetrating the plurality of fins 3 and for allowing a second fluid to flow therethrough. The plurality of heat transfer tubes 2 includes first heat transfer tubes 2 A and second heat transfer tubes 2 B arranged in a predetermined row direction that intersects the flow direction of the first fluid. The fins 3 have protrusions 5 each disposed between a first heat transfer tube 2 A and a second heat transfer tube 2 B, for guiding the first fluid toward the first heat transfer tube 2 A side and the second heat transfer tube 2 B side. The equivalent diameter of the protrusion 5 , as viewed in the axis direction of the heat transfer tubes 2 , is equal to or greater than the outer diameter of the heat transfer tubes 2.

1 . A fin-tube heat exchanger for exchanging heat between a first fluid and a second fluid, comprising:
 a plurality of fins arranged spaced apart from and parallel to each other so as to form a space or spaces for allowing the first fluid to flow therethrough; and   a plurality of heat transfer tubes penetrating said plurality of fins, for allowing the second fluid to flow therethrough, wherein:   said plurality of heat transfer tubes include a first heat transfer tube and a second heat transfer tube arranged in a predetermined row direction that intersects with a flow direction of the first fluid;   said first heat transfer tube and said second heat transfer tube are adjacent to each other with respect to the row direction;   each of said fins has a protrusion formed between said first heat transfer tube and said second heat transfer tube, said protrusion guiding the first fluid to said first heat transfer tube side and said second heat transfer tube side;   the equivalent diameter of said protrusion, as viewed in an axis direction of said heat transfer tubes, is equal to or greater than the outer diameter of said heat transfer tubes;   only one said protrusion is formed between said first heat transfer tube and said second heat transfer tube; and   said upstream edge of said protrusion is located upstream of centers of said first and second heat transfer tubes with respect to the flow direction of the first fluid.   
   
   
       2 . The fin-tube heat exchanger according to  claim 1 , wherein:
 the width of said protrusion along the row direction increases from an upstream edge of said protrusion to an intermediate portion thereof but decreases from said intermediate portion to a downstream edge thereof, along the flow direction of the first fluid;   a first slanted surface slanted toward said first heat transfer tube side so as to guide the first fluid toward said first heat transfer tube side, and a second slanted surface slanted toward said second heat transfer tube side so as to guide the first fluid toward said second heat transfer tube side, are formed between said upstream edge and said intermediate portion of said protrusion;   and   said intermediate portion of said protrusion is located upstream of downstream edges of said first and second heat transfer tubes.   
   
   
       3 . The fin-tube heat exchanger according to  claim 1 , wherein said heat transfer tubes and said protrusion are arrayed in a staggered manner, when viewed in an axis direction of said heat transfer tubes. 
   
   
       4 . The fin-tube heat exchanger according to  claim 1 , wherein said protrusion is formed in a pyramidal shape. 
   
   
       5 . The fin-tube heat exchanger according to  claim 4 , wherein said protrusion is formed in a quadrangular pyramidal shape. 
   
   
       6 . The fin-tube heat exchanger according to  claim 1 , wherein said protrusion is formed in a circular conic shape or an elliptic conic shape. 
   
   
       7 . The fin-tube heat exchanger according to  claim 1 , wherein said protrusion is formed in a circular hump shape or an elliptical hump shape. 
   
   
       8 . The fin-tube heat exchanger according to  claim 1 , wherein the ratio L/H is greater than 5.5, where L is the length of said protrusion with respect to the flow direction of the first fluid and H is the protruding height of said protrusion. 
   
   
       9 . The fin-tube heat exchanger according to  claim 1 , wherein the occupied area of said protrusion in each of said fins is from 43% to 73%. 
   
   
       10 . The fin-tube heat exchanger according to  claim 1 , wherein:
 said protrusion is such that, when said protrusion is orthogonally projected onto a plane parallel to said plurality of fins, an image of said protrusion appearing on the plane shows a circular shape or an elliptical shape; and   the area of the image of said protrusion appearing on the plane is greater than the cross-sectional area of each of said heat transfer tubes.   
   
   
       11 . (canceled) 
   
   
       12 . The fin-tube heat exchanger according to  claim 10 , wherein said upstream edge of said protrusion is located, with respect to the flow direction of the first fluid, closer to leading edges of said plurality of fins than upstream edges of said first heat transfer tube and said second heat transfer tube. 
   
   
       13 . The fin-tube heat exchanger according to  claim 10 , wherein said protrusion is such that the image thereof appearing on the plane is in an elliptical shape, and that the orientation of said protrusion is determined such that the minor axis of the ellipse is parallel to the row direction in which said first heat transfer tube and said second heat transfer tube are arranged. 
   
   
       14 . The fin-tube heat exchanger according to  claim 13 , wherein said protrusion is such that the location thereof relative to said first heat transfer tube and said second heat transfer tube is determined so that the major axis of the ellipse is contained in a virtual plane that perpendicularly bisects a line segment connecting the center of said first heat transfer tube and the center of said second heat transfer tube at the shortest distance. 
   
   
       15 . The fin-tube heat exchanger according to  claim 13 , wherein the shape of said protrusion is adjusted so that its surface forms a curve in a cross section that contains the minor axis or the major axis of the ellipse and is perpendicular to principal surfaces of said plurality of fins. 
   
   
       16 . The fin-tube heat exchanger according to  claim 15 , wherein said curve contains an inflection point between an upstream edge and an apex of said protrusion. 
   
   
       17 . The fin-tube heat exchanger according to  claim 15 , wherein said curve contains no inflection point between an upstream edge and an apex of said protrusion. 
   
   
       18 . The fin-tube heat exchanger according to  claim 13 , wherein the shape of said protrusion is adjusted so that its surface forms a sine curve in a cross section that contains the minor axis or the major axis of the ellipse and is perpendicular to principal surfaces of said plurality of fins. 
   
   
       19 . The fin-tube heat exchanger according to  claim 18 , wherein said surface follows a sine curve represented by the equation Y=Kcos(X) {K: constant, −180°≦X≦180°}. 
   
   
       20 . The fin-tube heat exchanger according to  claim 18 , wherein said surface follows a sine curve represented by the equation Y=Kcos(X) {K: constant, −90°≦X≦90°}. 
   
   
       21 . The fin-tube heat exchanger according to  claim 10 , wherein the shape of said protrusion is adjusted so that its surface forms a clothoid curve in a cross section that is parallel to the flow direction of the first fluid and is perpendicular to principal surfaces of said plurality of fins. 
   
   
       22 . The fin-tube heat exchanger according to  claim 1 , wherein the height of said protrusion is adjusted so as to satisfy the expression (FP/4)≦H≦FP, where H is the height of said protrusion and FP is the fin pitch, which is a parallel gap distance between said plurality of fins. 
   
   
       23 . The fin-tube heat exchanger according to  claim 10 , wherein the shape of said protrusion is adjusted so that the image thereof appearing on the plane shows a circular shape and that its surface forms a curve in a cross section that is perpendicular to principal surfaces of said plurality of fins. 
   
   
       24 . The fin-tube heat exchanger according to  claim 23 , wherein said curve contains an inflection point between said upstream edge and an apex of said protrusion. 
   
   
       25 . The fin-tube heat exchanger according to  claim 23 , wherein said curve contains no inflection point between an upstream edge and an apex of said protrusion. 
   
   
       26 . The fin-tube heat exchanger according to  claim 10 , wherein the shape of said protrusion is adjusted so that the image thereof appearing on the plane shows a circular shape and that its surface forms a sine curve in a cross section that is perpendicular to principal surfaces of said plurality of fins. 
   
   
       27 . The fin-tube heat exchanger according to  claim 26 , wherein said surface follows a sine curve represented by the equation Y=Kcos(X) {K: constant, −180°≦X≦180°}. 
   
   
       28 . The fin-tube heat exchanger according to  claim 26 , wherein said surface follows a sine curve represented by the equation Y=Kcos(X) {K: constant, −90°≦X≦90°}. 
   
   
       29 . The fin-tube heat exchanger according to  claim 1 , wherein:
 said heat transfer tubes are disposed in a staggered manner in two rows, one of the two rows being a front row that is closer to leading edges of said plurality of fins and the other row being a rear row that is parallel to the front row; and   another protrusion is formed between two adjacent ones of said heat transfer tubes disposed in the rear row, said other protrusion having the same shape and the same dimensions as those of said protrusion that is formed between two adjacent ones of said heat transfer tubes disposed in the front row.   
   
   
       30 . The fin-tube heat exchanger according to  claim 29 , wherein a second protrusion is formed between said protrusion formed in the front row and said other protrusion formed in the rear row, said second protrusion having a surface area smaller than that of said protrusion and said other protrusion. 
   
   
       31 . A fin used for the fin-tube heat exchanger according to  claim 1 . 
   
   
       32 . A heat pump apparatus comprising:
 a compressor for compressing a refrigerant;   a radiator for cooling the refrigerant compressed by said compressor;   an expansion mechanism for expanding the refrigerant cooled by said radiator; and   an evaporator for evaporating the refrigerant expanded by said expansion mechanism, wherein   at least one of said evaporator and said radiator comprises the fin-tube heat exchanger according to  claim 1 .   
   
   
       33 . A heat pump apparatus comprising:
 a compressor for compressing a refrigerant;   a radiator for cooling the refrigerant compressed by said compressor;   an expansion mechanism for expanding the refrigerant cooled by said radiator; and   an evaporator for evaporating the refrigerant expanded by said expansion mechanism, wherein at least said evaporator comprises the fin-tube heat exchanger according to  claim 1 .