Tube structures for heat exchanger

Abstract

A heat exchanger includes a plurality of fins and a plurality of tubes passing a fluid therethrough, extending through the plurality of fins and radially expanded into an interference fit therewith. At least one tube of the plurality of tubes includes an outer diameter, an inner diameter, and a plurality of ridges extending from the inner diameter inwardly into an interior of the tube. A tube internal surface area per unit of length of the tube multiplied by the ratio of the outer diameter and tube wall thickness is equal to or greater than about 30.0.

1 . A heat exchanger comprising:
 a plurality of fins;   a plurality of tubes passing a fluid therethrough, extending through the plurality of fins and radially expanded into an interference fit therewith, a least one tube of the plurality of tubes including:
 an outer diameter; 
 an inner diameter; and 
 a plurality of ridges extending from the inner diameter inwardly into an interior of the tube; 
 wherein a tube internal surface area per unit of length of the tube multiplied by the ratio of the outer diameter to a tube wall thickness between the outer diameter and the inner diameter, is equal to or greater than about 30.0. 
   
     
     
         2 . The heat exchanger of  claim 1 , wherein the plurality of ridges extend substantially axially along a length of the tube. 
     
     
         3 . The heat exchanger of  claim 1 , wherein the plurality of ridges extend helically along a length of the tube. 
     
     
         4 . The heat exchanger of  claim 1 , wherein the tube internal surface area per unit of length of the tube multiplied by the ratio of the outer diameter to the tube wall thickness between the outer diameter and the inner diameter, is equal to about 33.4. 
     
     
         5 . The heat exchanger of  claim 1 , wherein an internal free volume of the tube per unit of length confined between said ridges divided by a square of the outer diameter is equal to or greater than 0.040. 
     
     
         6 . The heat exchanger of  claim 5 , wherein a ratio of ridge cross-sectional area to a square of inner diameter is equal to or greater than about 0.0014. 
     
     
         7 . The heat exchanger of  claim 5 , wherein an internal free volume of the tube per unit of length divided by a square of the outer diameter is about 0.047. 
     
     
         8 . The heat exchanger of  claim 1 , wherein a ratio of the outer diameter to the inner diameter is less than or equal to about 1.185. 
     
     
         9 . The heat exchanger of  claim 1 , wherein a ratio of a top width of each ridge to the inner diameter multiplied by the number of ridges is equal to or greater than about 1.60. 
     
     
         10 . The heat exchanger of  claim 1 , wherein:
 a ratio of ridge cross-sectional area to a square of inner diameter is equal to or greater than about 0.0014; and   a ratio of ridge height to inner diameter is equal to or greater than about 0.045.   
     
     
         11 . The heat exchanger of  claim 1 , wherein the plurality of tubes is formed from and aluminum or aluminum alloy. 
     
     
         12 . A heat exchanger comprising:
 a plurality of fins;   a plurality of tubes passing a fluid therethrough, extending through the plurality of fins and radially expanded into an interference fit therewith, a least one tube of the plurality of tubes including:
 an outer diameter; 
 an inner diameter; and 
 a plurality of ridges extending from the inner diameter inwardly into an interior of the tube; 
 wherein an internal free volume of the tube per unit of length confined between said ridges divided by a square of the outer diameter is equal to or greater than 0.040. 
   
     
     
         13 . The heat exchanger of  claim 12 , wherein an internal free volume of the tube per unit of length confined between said ridges divided by a square of the outer diameter is about 0.047. 
     
     
         14 . The heat exchanger of  claim 12 , wherein a ratio of the outer diameter to the inner diameter is less than or equal to about 1.185. 
     
     
         15 . The heat exchanger of  claim 12 , wherein a ratio of a top width of each ridge to the inner diameter multiplied by a number of ridges in the plurality of ridges is equal to or greater than about 1.60. 
     
     
         16 . The heat exchanger of  claim 12 , wherein:
 a ratio of ridge cross-sectional area to a square of inner diameter is equal to or greater than about 0.0014; and   a ratio of ridge height to inner diameter is equal to or greater than about 0.045.   
     
     
         17 . A heat exchanger comprising:
 a plurality of fins;   a plurality of tubes passing a fluid therethrough, extending through the plurality of fins and radially expanded into an interference fit therewith, a least one tube of the plurality of tubes including:
 an outer diameter; 
 an inner diameter; and 
 a plurality of ridges extending from the inner diameter inwardly into an interior of the tube; 
 wherein a ratio of the outer diameter to the inner diameter is less than or equal to about 1.185. 
   
     
     
         18 . The heat exchanger of  claim 17 , wherein the ratio of the outer diameter to the inner diameter is less than or equal to about 1.181. 
     
     
         19 . The heat exchanger of  claim 17 , wherein a ratio of a top width of each ridge to the inner diameter multiplied by a number of ridges in the plurality of ridges is equal to or greater than about 1.60. 
     
     
         20 . The heat exchanger of  claim 17 , wherein:
 a ratio of ridge cross-sectional area to a square of inner diameter is equal to or greater than about 0.0014; and   a ratio of ridge height to inner diameter is equal to or greater than about 0.045.   
     
     
         21 . A heat exchanger comprising:
 a plurality of fins;   a plurality of tubes passing a fluid therethrough, extending through the plurality of fins and radially expanded into an interference fit therewith, a least one tube of the plurality of tubes including:
 an outer diameter; 
 an inner diameter; and 
   a plurality of ridges extending from the inner diameter inwardly into an interior of the tube;   wherein a ratio of a top width of each ridge to the inner diameter multiplied by a number of ridges in the plurality of ridges is equal to or greater than about 1.60.   
     
     
         22 . The heat exchanger of  claim 21 , wherein:
 a ratio of ridge cross-sectional area to a square of inner diameter is equal to or greater than about 0.0014; and   a ratio of ridge height to inner diameter is equal to or greater than about 0.045.   
     
     
         23 . A heat exchanger comprising:
 a plurality of fins;   a plurality of tubes passing a fluid therethrough, extending through the plurality of fins and radially expanded into an interference fit therewith, a least one tube of the plurality of tubes including:
 an outer diameter; 
 an inner diameter; and 
   a plurality of ridges extending from the inner diameter inwardly into an interior of the tube;   wherein:
 a ratio of ridge cross-sectional area to a square of inner diameter is equal to or greater than about 0.0014; and 
 a ratio of ridge height to inner diameter is equal to or greater than about 0.045.