Internal heat exchanger

Abstract

An internal heat exchanger includes an inner tube for a flow of a first fluid; an outer tube that is coaxial with the inner tube; a passageway between the inner tube and the outer tube for a flow of a second fluid; and, a flow enhancer inside the inner tube and configured to divert the flow of fluid in the inner tube along a wall of the inner tube.

What is claimed is: 
     
         1 . An internal heat exchanger comprising:
 an inner tube for a first flow of a first fluid;   an outer tube;   said inner tube and said outer tube being coaxial to each other;   said inner tube and said outer tube conjointly defining a passageway therebetween for a second flow of a second fluid;   said inner tube having an inner tube wall; and,   a flow enhancer arranged inside said inner tube and configured to divert said first flow of said first fluid along said inner tube wall.   
     
     
         2 . The internal heat exchanger of  claim 1 , wherein said flow enhancer is an elongate member. 
     
     
         3 . The internal heat exchanger of  claim 1 , wherein said flow enhancer includes a central portion and a plurality of radial members extending from said central portion. 
     
     
         4 . The internal heat exchanger of  claim 3 , wherein said central portion has a cylindrical shape. 
     
     
         5 . The internal heat exchanger of  claim 3 , wherein said radial members each have an outer portion in contact with said inner tube. 
     
     
         6 . The internal heat exchanger of  claim 1  further comprising a spring arranged between said inner tube and said outer tube. 
     
     
         7 . The internal heat exchanger of  claim 1  further comprising a plurality of longitudinal channels between said inner tube and said outer tube. 
     
     
         8 . The internal heat exchanger of  claim 1 , wherein said flow enhancer and said inner tube wall conjointly define a plurality of channels therebetween. 
     
     
         9 . A flow enhancer for an internal heat exchanger comprising:
 an axially extending central body; and,   a plurality of radial members extending from said central body.   
     
     
         10 . The flow enhancer of  claim 9 , wherein:
 said central body has an axial length; and,   at least one of said radial members is a continuous fin extending over the full extent of said axial length.   
     
     
         11 . The flow enhancer of  claim 9 , wherein:
 said central body has an axial length; and,   said radial members comprise a plurality of fins that extend along a portion of said axial length.