Multi-channel heat exchanger with improved condensate drainage

Abstract

A heat exchanger includes a first generally vertical header and a second generally vertical header and a generally vertical array of a plurality of generally flat heat exchange tubes extending in a horizontal direction therebetween. Each heat exchange tube has a plurality of channels extending longitudinally in parallel relationship from its inlet end to its outlet end, each channel defining a discrete refrigerant flow path. A plurality of fins extends between parallel-arrayed tubes. To facilitate drainage of the collected condensate from the external surfaces of the flat heat exchange tubes, the tubes are aligned at a slight angle with respect to the horizontal so that the trailing edge of each tube is positioned lower than the leading edge of each tube. To further assist in the condensate drainage, the trailing edge of each of the fins may extend beyond the trailing edge of the associated heat transfer tubes and a lower extension lip may extend downwardly from the trailing edge of each of the fins.

1 . A heat exchanger for cooling a flow of air passed therethrough comprising:
 first and second spaced apart and generally vertical longitudinally extending headers; and   at least one heat exchange tube having a flattened cross-section and defining at least one fluid flow path extending along a longitudinal axis thereof, said at least one heat flattened exchange tube extending longitudinally in a horizontal direction between said first and second headers and having an inlet to said fluid flow path opening in fluid communication to said first header and an outlet to said fluid flow path opening in fluid communication to the second header, said at least one flattened heat exchange tube having a transverse axis extending from a leading edge of said at least one flattened heat exchange tube to a trailing edge of said at least one flattened heat exchange tube, said leading edge disposed upstream with respect to air flow of said trailing edge, the transverse axis of said at least one flatted heat exchange tube disposed at an acute angle with the horizontal with said leading edge disposed vertically higher than said trailing edge.   
   
   
       2 . A heat exchanger as recited in  claim 1  wherein said at least one flattened heat exchange tube comprises a plurality of flattened heat exchange tubes disposed in parallel, spaced relationship in a generally vertical array. 
   
   
       3 . A heat exchanger as recited in  claim 2  further comprising a plurality of fins extending between adjacent tubes of said parallel tube array. 
   
   
       4 . A heat exchanger as recited in  claim 3  wherein said plurality of fins extends from a position aft of the leading edges of adjacent tubes of said parallel tube array to a position forward of the trailing edges of adjacent tubes of said tube array. 
   
   
       5 . A heat exchanger as recited in  claim 3  wherein said plurality of fins extends from a position aft of the leading edges of adjacent tubes of said parallel tube array to a position aft of the trailing edges of adjacent tubes of said tube array. 
   
   
       6 . A heat exchanger as recited in  claim 5  wherein the portion of each of said plurality of fins extending aft of the trailing edges of adjacent tubes of said tube array includes a lip portion extending behind the trailing edge of tube of said parallel array of tubes lying subadjacent said fin. 
   
   
       7 . A heat exchanger as recited in  claim 3  wherein said plurality of fins comprises a plurality of generally vertical plate-like fins extending between adjacent tubes of said parallel tube array. 
   
   
       8 . A heat exchanger as recited in  claim 3  wherein said plurality of fins comprises serpentine-like corrugated fins extending between adjacent tubes of said parallel tube array. 
   
   
       9 . A heat exchanger as recited in  claim 8  wherein said a serpentine-like corrugated fins extending between adjacent tubes of said parallel tube array are forming one of generally triangular, rectangular or trapezoidal airflow passages. 
   
   
       10 . A heat exchanger as recited in  claim 3  wherein said plurality of fins are at least one of louvered, wavy, offset strip or flat plate configurations. 
   
   
       11 . A heat exchanger as recited in  claim 1  wherein the transverse axis of said at least one flattened heat exchange tube is disposed at an acute angle with the horizontal in the range of from about 5 degrees to about 10 degrees. 
   
   
       12 . A heat exchanger as recited in  claim 11  wherein said at least one flattened heat exchange tube comprises a plurality of flattened heat exchange tubes disposed in parallel, spaced relationship in a generally vertical array. 
   
   
       13 . A heat exchanger as recited in  claim 11  further comprising a plurality of fins extending between adjacent tubes of said parallel tube array. 
   
   
       14 . A heat exchanger as recited in  claim 13  wherein said plurality of fins extends from a position aft of the leading edges of adjacent tubes of said parallel tube array to a position forward of the trailing edges of adjacent tubes of said tube array. 
   
   
       15 . A heat exchanger as recited in  claim 13  wherein said plurality of fins extends from a position aft of the leading edges of adjacent tubes of said parallel tube array to a position aft of the trailing edges of adjacent tubes of said tube array. 
   
   
       16 . A heat exchanger as recited in  claim 15  wherein the portion of each of said plurality of fins extending aft of the trailing edges of adjacent tubes of said tube array includes a lip portion extending behind the trailing edge of tube of said parallel array of tubes lying subadjacent said fin. 
   
   
       17 . A heat exchanger as recited in  claim 13  wherein said plurality of fins comprises a plurality of generally vertical plate-like fins extending between adjacent tubes of said parallel tube array 
   
   
       18 . A heat exchanger as recited in  claim 13  wherein said plurality of fins comprises serpentine-like corrugated fins extending between adjacent tubes of said parallel tube array. 
   
   
       19 . A heat exchanger as recited in  claim 18  wherein said a serpentine-like corrugated fins extending between adjacent tubes of said parallel tube array are forming one of generally triangular, rectangular or trapezoidal airflow passages. 
   
   
       20 . A heat exchanger as recited in  claim 13  wherein said plurality of fins are at least one of louvered, wavy, offset strip or flat plate configurations. 
   
   
       21 . A heat exchanger as recited in  claim 1  wherein said at least one flattened heat exchange tube defines at least one refrigerant flow path extending along a longitudinal axis thereof. 
   
   
       22 . A heat exchanger as recited in  claim 1  wherein said at least one flattened heat exchange tubes defines a plurality of parallel refrigerant flow paths extending parallel to a longitudinal axis thereof, each refrigerant flow path of said plurality of parallel refrigerant flow paths having an inlet to said refrigerant flow path opening in fluid communication to said first header and an outlet to said refrigerant flow path opening in fluid communication to the second header. 
   
   
       23 . A heat exchanger as recited in  claim 22  wherein said plurality of parallel fluid flow paths form at least one of rectangular, triangular, trapezoidal, circular or oval channels for refrigerant flowing herethrough. 
   
   
       24 . A heat exchanger as recited in  claim 1  wherein said at least one flattened heat transfer tube has internal heat transfer enhancement elements. 
   
   
       25 . A heat exchanger as recited in  claim 1  wherein said at least one flattened heat transfer tube has one of rectangular or oval cross-section. 
   
   
       26 . A heat exchanger as recited in  claim 1  wherein said heat exchanger is a refrigerant system evaporator. 
   
   
       27 . A heat exchanger as recited in  claim 1  wherein said heat exchanger has a single-pass configuration. 
   
   
       28 . A heat exchanger as recited in  claim 1  wherein said heat exchanger has a multi-pass configuration.