Fin Body For A Heat Exchange Tube

Abstract

The present invention relates to a fin body intended for being housed inside a heat exchange tube which is one from among heat exchange tubes showing a planar configuration. The fin body is configured in the form of a plate, this plate being the one inserted into the heat exchange tube. The plate is configured from a metal sheet bent into a plurality of consecutive bends. The invention is characterized by a range of characteristic width to height ratio in the interval of 0.15-0.5, and according to more specific cases, in the lower subranges. As a result, the fin gives rise to a heat exchange tube with a higher efficiency than fins known in the state of the art without penalizing the pressure drop.

1 . A fin body ( 1 ) to be housed inside a heat exchange tube ( 2 ) having a planar configuration, which heat exchange tube is from among the exchange tubes extending along a longitudinal direction X-X′ and comprising two planar inner faces ( 2 . 1 ,  2 . 2 ) parallel to and facing one another;
 the fin body ( 1 ) is configured in the form of a plate and formed from a metal sheet having a thickness e, bent into a plurality of consecutive bends extending according to a direction Z, wherein the direction Z is intended for being parallel to the longitudinal direction X-X′ of the heat exchange tube ( 2 ) housing it, and wherein; 
 the bends are configured by alternating between a first plane (P 1 ) and a second plane (P 2 ) parallel to the first plane (P 1 ), and with both planes being spaced from one another, wherein the first plane (P 1 ) and the second plane (P 2 ) are intended to coincide with the planar inner faces of the heat exchange tube ( 2 ) parallel to and facing one another; 
 the bends, according to a transverse section (P T ) with respect to direction z, show a periodic zigzag wavy path (T), wherein
 said wavy path (T) comprises segments ( 1 . 1 ), the segments ( 1 . 1 ) being connected by vertices ( 1 . 2 ) located in the peaks of maximum amplitude; 
 the characteristic width (s) is half the wavelength of the wavy path (T) and the characteristic height (h) is the distance between peaks of maximum amplitude of the wavy path (T), 
 
 
       characterized in that the wavy path (T) according to the transverse section (P T ) has a channel width (S ch ) to plate height (h out ) ratio in the interval of [0.15-0.5], wherein s ch =s−e and h out =h+e. 
     
     
         2 . The body ( 1 ) according to  claim 1 , wherein the channel width (s ch ) to plate height (h out ) ratio is in the interval of [0.3-0.4]. 
     
     
         3 . The body ( 1 ) according to  claim 1 , wherein the channel width (s ch ) to plate height (h out ) ratio is in the interval of [0.35-0.36]. 
     
     
         4 . The body ( 1 ) according to  claim 1 , wherein the segments ( 1 . 1 ) connected by vertices ( 1 . 2 ) are straight. 
     
     
         5 . The body ( 1 ) according to  claim 1 , wherein the segments ( 1 . 1 ) connected by vertices ( 1 . 2 ) are oblique with respect to the normal to any of the planes (P 1 , P 2 ). 
     
     
         6 . The body ( 1 ) according to  claim 1 , wherein the segments ( 1 . 1 ) are connected with the vertices ( 1 . 2 ) by means of curved portions ( 1 . 3 ). 
     
     
         7 . The body ( 1 ) according to  claim 1 , wherein the zigzag transverse section (P T ) extends according to direction Z following a longitudinal wavy path. 
     
     
         8 . The body ( 1 ) according to  claim 7 , wherein the longitudinal wavy path has a minimum characteristic radius (r) to pitch (p), r/p, ratio in the range of [0.2, 2], more preferably in the range of [0.2-1], and more preferably in the range of [0.4, 0.5]. 
     
     
         9 . The body ( 1 ) according to  claim 8 , wherein the longitudinal wavy path is configured by the concatenation of curved segments with a constant radius, alternating the curvature on both sides according to the projection on the horizontal plane of the fin body ( 1 ). 
     
     
         10 . A heat exchange tube ( 2 ) having a planar configuration and extending along a longitudinal direction X-X′ and with at least two planar inner faces ( 2 . 1 ,  2 . 2 ), parallel to and facing one another, said tube comprising a fin body ( 1 ) according to  claim 1  housed therein, wherein the fin body ( 1 ) is oriented such that:
 the first plane (P 1 ) coincides with a first inner face ( 2 . 1 ) of the heat exchange tube ( 2 ), 
 the second plane (P 2 ) coincides with a second inner face ( 2 . 2 ) facing the first inner face ( 2 . 1 ) of heat exchange tube ( 2 ), and 
 the direction Z of the fin body ( 1 ) extends parallel to the longitudinal direction X-X′ of the heat exchange tube ( 2 ); and wherein 
 
       the fin body ( 1 ) is attached by welding to the planar inner faces ( 2 . 1 ,  2 . 2 ) of the heat exchange tube ( 2 ) forming channels (CH). 
     
     
         11 . The heat exchange tube ( 2 ) according to  claim 10 , wherein at least one attachment between the fin body ( 1 ) and the heat exchange tube ( 10 ) is by brazing and it is established between a vertex ( 1 . 2 ) of the fin body ( 1 ) and an inner face ( 2 . 1 ,  2 . 2 ) of the heat exchange tube ( 2 ) with a concave welding meniscus (M) curving towards any of the adjacent spaces. 
     
     
         12 . A heat exchanger comprising at least one heat exchange tube ( 2 ) according to  claim 10 .