Heat exchanger

Abstract

A heat exchanger comprises a primary flow path arranged to contain a first heat exchanging medium. A secondary flow path arranged to contain a secondary heat exchanging medium, wherein the primary flow path surrounds the secondary flow path for exchanging heat between the two paths.

1 . A heat exchanger comprising:
 a primary flow path arranged to contain a first heat exchanging medium;   a secondary flow path arranged to contain a secondary heat exchanging medium, wherein the primary flow path surrounds the secondary flow path for exchanging heat between the two paths.   
     
     
         2 . A heat exchanger in accordance with  claim 1 , wherein the primary flow path is helical. 
     
     
         3 . A heat exchanger in accordance with  claim 1 , wherein the primary flow path is partitioned. 
     
     
         4 . A heat exchanger in accordance with  claim 1 , wherein the primary flow path is surrounded by one or more heat exchanging fins. 
     
     
         5 . A heat exchanger in accordance with  claim 1 , further comprising a tube and wherein the secondary medium is carried within a body of the tube and the primary medium is carried within a circumferential outer wall of the body. 
     
     
         6 . A heat exchanger in accordance with  claim 5 , wherein the tube has a circular cross section. 
     
     
         7 . A heat exchanger in accordance with  claim 5 , further comprising an inlet manifold coupled to a first end of the tube and having a fluid path flow in fluid connection with the primary flow path of the tube for delivery of the first medium. 
     
     
         8 . A heat exchanger in accordance with  claim 7 , further comprising an outlet manifold coupled to a second end of the tube and having a fluid path flow in fluid connection with the primary flow path for expelling the first medium. 
     
     
         9 . A heat exchanger in accordance with  claim 7 , further comprising a plurality of tubes and wherein the inlet and outlet manifold each comprise a manifold tube having openings defined along their length for receiving corresponding ends of the respective exchanger tubes. 
     
     
         10 . A heat exchanger in accordance with  claim 9 , wherein an inner surface of the circumferential wall for each tube extends through the manifold tube and meets with a second opening in the manifold tube for receiving/expelling the secondary or third medium. 
     
     
         11 . A method of constructing a heat exchanger comprising forming a primary path flow arranged to contain a primary heat exchanging medium so as to surround a secondary path flow arranged to carry a secondary heat exchanging medium. 
     
     
         12 . A method in accordance with  claim 11 , wherein the primary flow path is a helical flow path. 
     
     
         13 . A method in accordance with  claim 12 , further comprising forming the helical flow path by winding or extruding a length of a primary tube having a generally elongate cross section such that the length extends along a helical path. 
     
     
         14 . A method in accordance with  claim 13 , further comprising winding/extruding the length of tube such that a closed outer circumferential wall is formed so as to define the secondary flow path. 
     
     
         15 . A method in accordance with  claim 13 , further comprising locating an inner tube arranged to carry the secondary medium within the wound length of primary tube. 
     
     
         16 . A method in accordance with  claim 14 , further comprising coupling a first end of the primary tube to an opening in an inlet tube arranged to deliver the first medium such that the primary flow path is in fluid communication with the inside of the inlet tube. 
     
     
         17 . A method in accordance with  claim 14 , further comprising coupling a second end of the primary tube to an opening in an outlet tube arranged to expel the first medium such that the primary flow path is in fluid communication with the inside of the outlet tube. 
     
     
         18 . A method in accordance with  claim 16 , further comprising passing the secondary flow path through a second opening in the respective inlet/outlet tube for delivering/expelling the secondary medium.