Heat exchanger

Abstract

A brazing material in a paste form is applied to dented portions formed on the outer surface of a core pipe, and then a pipe is disposed on the pipe, and brazing in a furnace. In this way, the brazing material that was melted by the heat will be reliably poured into the dented portions and bonded thereto after being cooled down. Thus, the dented portions formed on the outer surface of the core pipe can be reliably filled with the brazing material, which consequently eliminates a poor contact between the core pipe and the winding pipe. In addition, even if the wall thickness of portions in which projections are formed are made thinner in the process of forming the projections, the dented portions formed on the outer surface are filled with the brazing material, so that the core pipe thickness can be reinforced, and the reduction in strength of the portions with the projections can be prevented.

1 . A heat exchanger configured to exchange heat between a first fluid and a second fluid, comprising:
 a core pipe having a passage for communicating a first fluid and provided with projections on an inner surface thereof by pressing an outer surface of the core pipe, and dented portions that are formed on the outer surface of the core pipe;   a winding pipe having a passage for communicating a second fluid separated from the first fluid and being wound around the outer surface of the core pipe; and   a brazing material poured into the dented portions of the core pipe proximate the winding pipe.   
   
   
       2 . The heat exchanger according to  claim 1 , wherein
 the brazing material is in a paste form, which is applied to the dented portions of the core pipe in advance and then melted and bonded thereto.   
   
   
       3 . The heat exchanger according to  claim 1 , wherein
 the brazing material is in a linear form, which is disposed between the core pipe and the winding pipe in advance and then is melted and bonded thereto.   
   
   
       4 . The heat exchanger according to  claim 1 , wherein
 the brazing material is in a linear form, which is disposed on the winding pipe wound around the core pipe in advance and then melted and bonded thereto.   
   
   
       5 . The heat exchanger according to  claim 1 , wherein
 the brazing material is in a paste form, which is applied to the winding pipe wound around the core pipe in advance and then melted and bonded thereto.