Optimized tube bundle configuration for controlling a heat exchanger wall temperature

Abstract

A heat exchanger comprises: a first medium inlet operable to receive a first medium into the heat exchanger; a first medium outlet operable to expel the first medium from the heat exchanger; a second medium inlet operable to receive a second medium into the heat exchanger; a second medium outlet operable to expel the second medium from the heat exchanger; and a plurality of parallel tubes running from the second medium inlet to the second medium outlet operable to carry the second medium from the second medium inlet to the second medium outlet, the plurality of tubes including: a first section of a first plurality of tubes, at least one of the first plurality of tubes having a first diameter, situated so that the first medium first flows from the first medium inlet over exterior walls of the first plurality of tubes and through gaps between the first plurality of tubes; and a second section of a second plurality of tubes, at least one of the second plurality of tubes having a second diameter that is different than the first diameter, situated so that after the first medium flows past the first section of the first plurality of tubes the first medium then flows over exterior walls of the second plurality of tubes and through gaps between the second plurality of tubes to the first medium outlet.

1 . A heat exchanger comprising:
 a first medium inlet operable to receive a first medium into the heat exchanger;   a first medium outlet operable to expel the first medium from the heat exchanger;   a second medium inlet operable to receive a second medium into the heat exchanger;   a second medium outlet operable to expel the second medium from the heat exchanger; and   a plurality of parallel tubes running from the second medium inlet to the second medium outlet operable to carry the second medium from the second medium inlet to the second medium outlet, the plurality of tubes including:
 a first section of a first plurality of tubes, at least one of the first plurality of tubes having a first diameter, situated so that the first medium first flows from the first medium inlet over exterior walls of the first plurality of tubes and through gaps between the first plurality of tubes; and 
 a second section of a second plurality of tubes, at least one of the second plurality of tubes having a second diameter that is different than the first diameter, situated so that after the first medium flows past the first section of the first plurality of tubes the first medium then flows over exterior walls of the second plurality of tubes and through gaps between the second plurality of tubes to the first medium outlet. 
   
     
     
         2 . The heat exchanger of  claim 1 , wherein:
 the first section of the plurality of tubes have a first tube spacing and arrangement; and   the second section of the second plurality of tubes have a second tube spacing and arrangement that is different than the first section.   
     
     
         3 . The heat exchanger of  claim 1 , wherein the plurality of parallel tubes further comprises:
 a third section of a third plurality of tubes each having a third diameter that is different than the second diameter, situated so that after the first medium flows past the second section of the second plurality of tubes the first medium then flows over exterior walls of the third section of the plurality of tubes and through gaps between the third plurality of tubes to the first medium outlet.   
     
     
         4 . The heat exchanger of  claim 3 , wherein:
 the first section of the first plurality of tubes comprises a first rectilinear array of parallel tubes;   the second section of the second plurality of tubes comprises a second rectilinear array of parallel tubes; and   the third section of the third plurality of tubes comprises a third rectilinear array of parallel tubes.   
     
     
         5 . The heat exchanger of  claim 1 , wherein:
 the first medium flows orthogonal to the plurality of parallel tubes.   
     
     
         6 . The heat exchanger of  claim 1 , wherein:
 the first medium is at a first temperature; and   the second medium is at a second temperature that is different from the first temperature.   
     
     
         7 . The heat exchanger of  claim 6 , wherein:
 the first medium is at a higher temperature compared to the second medium;   
     
     
         8 . The heat exchanger of  claim 7 , wherein:
 the first medium flowing out of the first medium outlet is at a lower temperature compared to the first medium flowing into the first medium inlet; and   the second medium flowing out of the second medium outlet is at a higher temperature compared to the second medium flowing into the second medium inlet.   
     
     
         9 . The heat exchanger of  claim 1 , wherein:
 the second medium flowing through the first plurality of tubes has a first flow rate through the first plurality of tubes that is higher than a second flow rate of the second medium flowing through the second plurality of tubes.   
     
     
         10 . A heat exchanger, comprising:
 a first section of a first plurality of tubes capable of carrying a first medium, the first section including a first number of tubes, at least one of the first plurality of tubes having first wall thickness, wherein the first plurality of tubes are situated so that after a second medium flows into the heat exchanger the second medium then flows over exterior walls of the first plurality of tubes and through first gaps between the first plurality of tubes; and   a second section of a second plurality of tubes including a second number of tubes that is more than the first number of tubes, at least one of the second plurality of tubes having a second wall thickness that is different than the first wall thickness, wherein the second plurality of tubes are situated so that after the second medium flows past the first section of the first plurality of tubes the second medium then flows over exterior walls of the second plurality of tubes and through second gaps between the second plurality of tubes.   
     
     
         11 . The heat exchanger of  claim 10 , wherein:
 the first gaps between the first plurality of tubes are a first uniform distance within the first section of the first plurality of tubes; and   the second gaps between the second plurality of tubes are a second uniform distance within the second section of the second plurality of tubes.   
     
     
         12 . The heat exchanger of  claim 10 , wherein:
 the first section of the first plurality of tubes comprises a first rectilinear array of tubes; and   the second section of the second plurality of tubes comprises a second rectilinear array of tubes.   
     
     
         13 . The heat exchanger of  claim 10 , further comprising:
 a third section of a third plurality of tubes including a third number of tubes that is more than the second number of tubes, at least one of the third plurality of tubes having a third diameter that is different than the second diameter, wherein the third plurality of tubes are situated so that after the second medium flows past the second section of the second plurality of tubes the second medium then flows over exterior walls of the third plurality of tubes and through third gaps between the third plurality of tubes.   
     
     
         14 . The heat exchanger of  claim 10 , wherein the second medium is at a higher temperature than the first medium. 
     
     
         15 . The heat exchanger of  claim 14 , wherein the first medium comprises fuel and the first medium comprises air. 
     
     
         16 . The heat exchanger of  claim 10 , wherein the first plurality of tubes carries the first medium from a first medium inlet to a first medium outlet within the heat exchanger. 
     
     
         17 . A method comprising:
 passing a first medium through a plurality of tubes;   passing a second medium over first exterior walls of and through first gaps between first tubes in a first section of the plurality of tubes, wherein the tubes in the first section of the plurality of tubes have a first diameter; and   passing the second medium over second exterior walls of and through second gaps between second tubes in a second section of the plurality of tubes after the second medium exits the first gaps, wherein the tubes in the second section of the plurality of tubes have a second diameter that is different than the first diameter.   
     
     
         18 . The method of  claim 17 , further comprising:
 expelling the second medium through a second outlet after the second medium exits the second gaps; and   expelling the first medium through a first outlet.   
     
     
         19 . The method of  claim 17 , wherein the passing the second medium over the first exterior walls of and through the first gaps between the first tubes in the first section of the plurality of tubes further comprises:
 exchanging heat between the second medium and first medium carried within the first tubes in the first section of the plurality of tubes.   
     
     
         20 . The method of  claim 17 , wherein the passing the second medium over the first exterior walls of and through the first gaps between the first tubes in the first section of the plurality of tubes further comprises:
 passing the second medium orthogonal to the first tubes of the first section of the plurality of tube.