Multi-channel tube for heat exchangers, made of folded metal sheet

Abstract

A tube for a heat exchanger comprises a plate provided with a plurality of parallel flow ports, wherein the plate is formed by a single folded-up metal sheet and consists of an envelope formed by a first portion of the metal sheet, and of a partition structure formed by a second portion of the metal sheet, which extends in an corrugated manner within the envelope so as to define said flow ports therewith, and wherein the partition structure has a substantially polygonal profile having connection segments interconnecting opposite walls of the envelope and being interposed between adjacent flow ports. The connection segments are slanted relative to the opposite walls of the envelope, thereby defining an angle a>0° relative to the normal to said walls.

1 - 12 . (canceled) 
     
     
         13 . A tube for a heat exchanger, comprising a plate provided with a plurality of parallel flow ports,
 wherein said plate is formed by a single folded-up metal sheet and consists of an envelope formed by a first portion of the metal sheet, and of a partition structure formed by a second portion of the metal sheet, which extends in a corrugated manner within the envelope so as to define said flow ports along therewith, and   wherein said partition structure has a substantially polygonal profile having connection segments interconnecting opposite walls of the envelope and being interposed between adjacent flow ports, and   wherein said connection segments are inclined with respect to the opposite walls of the envelope, thereby defining an angle α>0° with respect to the normal to said walls.   
     
     
         14 . The tube according to  claim 13 , wherein at least the central ports of said flow ports have an approximately trapezoid section, and said partition structure further comprises base segments alternated with said connection segments, approximately parallel to the opposite walls of said envelope, and in contact to either one thereof, wherein said base segments have a corrugated transversal profile, thereby each of said base segments has, at the side ends thereof, respective ridge portions which join each base segment to the connection segments adjacent thereto, and a depression portion interposed between said ridge portions, and defining a recess in the transversal direction relative thereto. 
     
     
         15 . The tube according to  claim 13 , wherein said partition structure defines a plurality of corrugations, whose height h before closing the envelope on said structure, intended as the difference in height between the maximum and minimum height points of the corrugations, is greater than the separation distance H between the opposite walls of said envelope after the latter has been closed. 
     
     
         16 . The tube according to  claim 13 , said tube being intended to be coupled to a distributor for a heat exchanger, and having an end portion suitable to be inserted into a corresponding slot that is provided on a wall of the distributor, wherein said end portion is provided with abutment means suitable to define a stop position for fitting said tube into the slot, said abutment means further providing slanted surfaces relative to the outer surface of the tube envelope, which are suitable to engage corresponding coupling portions provided on the edge of the slot. 
     
     
         17 . The tube according to  claim 16 , wherein said abutment means comprise one or more projections and/or grooves provided on said envelope. 
     
     
         18 . The tube according to  claim 16 , wherein said abutment means comprise an abutment length of said end portion of the tube, at which the end portion of the tube is widthwise tapered towards the axial end of the tube. 
     
     
         19 . The tube according to  claim 16 , wherein said end portion of the tube further comprises a fitting length, at which the end portion of the tube is widthwise tapered towards the axial end of the tube, in order to facilitate the fitting of the end portion into the slot. 
     
     
         20 . The tube according to  claim 18 , wherein said tube end portion comprises in order, from the axial end towards the center of the tube, a fitting length, at which the end portion of the tube is widthwise tapered towards the axial end of the tube, in order to facilitate the fitting at the end portion into the slot, a sealing length and said abutment length, said sealing length being suitable to engage the edge of the slot. 
     
     
         21 . The tube according to  claim 13 , wherein at least the central ports of said flow ports have an isosceles trapezoid cross section, said connection segments defining an angle 0<α≦arccos(⅗) relative to the normal to the opposite walls of the envelope. 
     
     
         22 . The tube according to  claim 13 , wherein a first edge strip of the metal sheet associated with the first portion of said sheet is welded to the outer side of the envelope, and a second edge strip of the metal sheet associated with the second portion of said sheet, adjacent to the separation structure, is welded to the inner side of the envelope. 
     
     
         23 . The tube according to  claim 22 , wherein said edge strips of the metal sheet are positioned at opposite side ends of the plate. 
     
     
         24 . The tube according to  claim 13 , wherein said metal sheet has an overall thickness d such as 0.2 mm≦d≦0.35 mm, and has, on each face of the sheet, a clad of brazing filler metal with a clad to core ratio c%, resulting from the ratio of the clad thickness to the overall thickness d, 5%≦c%≦15%.