Heat exchanger

Abstract

The outer surface of a core pipe 31 is pressed so as to form projections 313 on the inner surface of the core pipe 31 , and a winding pipe 32 is helically wound around the outer circumference of the core pipe 31 . Subsequently, the core pipe 31 and the winding pipe 32 are bent together, and brazing is performed. As a result, the outer surface of the winding pipe 32 is in contact with the outer surface of the core pipe 31 without any gap therebetween at a bending center portion (D), and the outer surface of the winding pipe ( 32 ) is bonded to the outer surface of the core pipe ( 31 ) by a brazing material ( 33 ) at the bending center portion (D) of the bent part C-C.

1 . A heat exchanger comprising:
 a core pipe having projections that are formed on an inner surface thereof by pressing an outer surface of the core pipe; and   a winding pipe that is wound around the outer surface of the core pipe, wherein   the core pipe has a linear part and a bent part,   the outer surface of the winding pipe is in contact with the outer surface of the core pipe without any gap therebetween at a bending center portion of the bent part, and   the outer surface of the winding pipe is bonded to the outer surface of the core pipe by a brazing material at the bending center portion of the bent part.   
   
   
       2 . A method for manufacturing a heat exchanger including a core pipe and a winding pipe, comprising:
 pressing the outer surface of the core pipe so as to form projections on the inner surface thereof,   winding the winding pipe around the outer surface of the core pipe;   bending the core pipe with the winding pipe being wound around the outer surface of the core pipe; and   brazing the outer surface of the winding pipe and the outer surface of the core pipe by a brazing material.   
   
   
       3 . A heat exchanger comprising:
 a core pipe having projections that are formed on an inner surface thereof by pressing an outer surface of the core pipe;   a winding pipe that is wound around the outer surface of the core pipe; and   a brazing material that brazes the outer surface of the winding pipe to the outer surface of the core pipe,   wherein   the core pipe includes a bent part that is formed by bending the core pipe with the winding pipe being wound around the outer surface of the core pipe.