Flat Tube and Heat Exchanger

Abstract

The present disclosure provides a flat tube and a heat exchanger, in which a bent section is formed in the middle of the flat tube, regions of the flat tube outside the bent section form two straight sections, the bent section includes a bent portion and two twisting portions, two ends of each twisting portion are connected to one end of the bent section and one straight section respectively; wherein the bent portion bends around an axis parallel to the thickness direction of the flat tube, the minimum radius of curvature of the inner side of the bent portion is RNmin, and the thickness of the flat tube is t, t<RNmin<5t.

What is claimed is: 
     
         1 . A flat tube, wherein
 a bent section is formed in a middle of the flat tube, regions of the flat tube outside the bent section form two straight sections, the bent section comprises a bent portion and two twisting portions, two ends of each twisting portion are connected to an end of the bent section and one straight section respectively;   wherein the bent portion bends around an axis parallel to a thickness direction of the flat tube, a minimum radius of curvature of an inner side of the bent portion is RNmin, and a thickness of the flat tube is t, t<RNmin<5t.   
     
     
         2 . The flat tube according to  claim 1 , wherein a maximum radius of curvature of the inner side of the bent portion is RNmax, t<RNmax<5t. 
     
     
         3 . The flat tube according to  claim 1 , wherein a minimum radius of curvature of an outer side of the bent portion RWmin, t<RWmin<5t. 
     
     
         4 . The flat tube according to  claim 1 , wherein
 a maximum radius of curvature of an outer side of the bent portion RWmax, t<RWmax<5t.   
     
     
         5 . The flat tube according to  claim 1 , wherein RNmin is 4.5t, 4t or 3t. 
     
     
         6 . The flat tube according to  claim 1 , wherein
 a maximum radius of curvature of the inner side of the bent portion is RNmax, RNmax≥5t; and   a minimum radius of curvature of an outer side of the bent portion RWmin, RWmin≥5t.   
     
     
         7 . The flat tube according to  claim 1 , wherein joints of the two twisting portions and the bent portion respectively have preset tangent lines, an included angle between the two preset tangent lines is θ, and an included angle between the two straight sections is α, where α>θ. 
     
     
         8 . The flat tube according to  claim 7 , wherein α≤90°. 
     
     
         9 . The flat tube according to  claim 1 , wherein the flat tube has a preset symmetrical surface, the symmetrical surface divides the bent portion into two symmetrical portions, the two twisting portions are symmetrically arranged relative to the symmetrical surface, and the two straight sections are symmetrically arranged relative to the symmetrical surface. 
     
     
         10 . A heat exchanger, wherein the heat exchanger comprises a plurality of flat tubes according to  claim 1 , the plurality of flat tubes arranged side by side, and fins are arranged between straight sections of two adjacent flat tubes. 
     
     
         11 . The heat exchanger according to  claim 10 , wherein a maximum radius of curvature of the inner side of the bent portion is RNmax, t<RNmax<5t. 
     
     
         12 . The heat exchanger according to  claim 10 , wherein a minimum radius of curvature of an outer side of the bent portion is RWmin, t<RWmin<5t. 
     
     
         13 . The heat exchanger according to  claim 10 , wherein
 a maximum radius of curvature of an outer side of the bent portion is RWmax, t<RWmax<5t.   
     
     
         14 . The heat exchanger according to  claim 10 , wherein RNmin is 4.5t, 4t or 3t. 
     
     
         15 . The heat exchanger according to  claim 10 , wherein
 a maximum radius of curvature of the inner side of the bent portion is RNmax, RNmax≥5t; and   a minimum radius of curvature of an outer side of the bent portion is RWmin, RWmin≥5t.   
     
     
         16 . The heat exchanger according to  claim 10 , wherein joints of the two twisting portions and the bent portion respectively have preset tangent lines, an included angle between the two preset tangent lines is θ, and an included angle between the two straight sections is α, where α>θ. 
     
     
         17 . The heat exchanger according to  claim 16 , wherein α≤90°. 
     
     
         18 . The heat exchanger according to  claim 10 , wherein the flat tube has a preset symmetrical surface, the symmetrical surface divides the bent portion into two symmetrical portions, the two twisting portions are symmetrically arranged relative to the symmetrical surface, and the two straight sections are symmetrically arranged relative to the symmetrical surface.