Heat exchanger tubes

Abstract

A tube for a thermal transfer device can include a wall having a length and having an inner surface and an outer surface, wherein the inner surface forms a cavity. The tube can also include at least one first dimple pressed into the wall toward the cavity at a first location along the length of the wall, where the inner surface of the wall at the at least one first dimple is separated from itself by a first distance. The tube can further include at least one second dimple pressed into the wall toward the cavity at a second location along the length of the wall, where the inner surface of the wall at the at least one second dimple is separated from itself by a second distance. The cavity can be configured to receive a fluid that flows continuously along a length of the at least one wall.

What is claimed is: 
     
         1 . A heat exchanger tube comprising:
 a wall having an inner wall defining a cavity, a first end, and a second end opposite the first end, the cavity being configured to direct a flow of fluid flowing in a direction from the first end toward the second end;   a first dimple set located at a first dimple location between the first and second ends, the first dimple set comprising one or more first dimples extending inwardly toward the cavity, the one or more first dimples having a first dimple depth equal to a radial distance between the inner wall at the first dimple location and the inner wall at a non-dimpled location; and   a second dimple set located at a second dimple location between the first and second ends, the second dimple set comprising one or more second dimples extending inwardly toward the cavity, the one or more second dimples having a second dimple depth equal to a radial distance between the inner wall at the second dimple location and the inner wall at the non-dimpled location,   wherein the second dimple location is different from the first dimple location and the second dimple depth is different from the first dimple depth.   
     
     
         2 . The heat exchanger tube of  claim 1 , wherein at least one of the one or more first dimples or the one or more second dimples comprises a pair of dimples extending inwardly from opposing sides of the cavity. 
     
     
         3 . The heat exchanger tube of  claim 1 , wherein at least one of the one or more first dimples or the one or more second dimples comprises three or more dimples. 
     
     
         4 . The heat exchange tube of  claim 1 , wherein the one or more first dimples comprises a first number of dimples and the one or more second dimples comprises a second number of dimples, the second number being different from the first number. 
     
     
         5 . The heat exchanger tube of  claim 1 , wherein the one or more first dimples has a first dimple shape and the one or more second dimples has a second dimple shape that is different from the first dimple shape. 
     
     
         6 . The heat exchanger tube of  claim 1 , wherein the one or more first dimples has a first dimple angle and the one or more second dimples has a second dimple angle that is different from the first dimple angle. 
     
     
         7 . The heat exchanger tube of  claim 1  further comprising:
 a third dimple set located at a third dimple location between the first and second ends, the third dimple set comprising one or more third dimples extending inwardly toward the cavity, the one or more third dimples having a third dimple depth equal to a radial distance between the inner wall at the first dimple location and the inner wall at a non-dimpled location, 
 wherein the third dimple location is different from both the first and second dimple locations and the third dimple depth is different from at least one of the first dimple depth or the second dimple depth. 
 
     
     
         8 . The heat exchanger tube of  claim 7 , wherein:
 the second dimple set is circumferentially rotated relative the first dimple set such that the second dimple set is positioned at a first angle relative the first dimple set,   the third dimple set is circumferentially rotated relative the first dimple set such that the third dimple set is positioned at a second angle relative the first dimple set, and the second angle is different from the first angle.   
     
     
         9 . The heat exchanger tube of  claim 7 , wherein a longitudinal distance between the first dimple set and the second dimple set is greater than a longitudinal distance between the second dimple set and the third dimple set. 
     
     
         10 . The heat exchanger tube of  claim 7 , wherein a longitudinal distance between the first dimple set and the second dimple set is less than a longitudinal distance between the second dimple set and the third dimple set. 
     
     
         11 . A heat exchanger tube comprising:
 a wall having an inner wall defining a cavity, a first end, and a second end opposite the first end, the cavity being configured to direct a flow of fluid flowing in a direction from the first end toward the second end;   a plurality of dimple sets, each dimple set being located at a corresponding location along a length of the wall, each of the plurality of dimple sets comprising:
 one or more dimples extending inwardly toward the cavity, each of the one or more dimples having a dimple depth equal to a radial distance between the inner wall at the corresponding dimple of the one or more dimples and the inner wall at a non-dimpled location, 
   wherein at least one of the plurality of dimple sets has a dimple depth that is different from a dimple depth of at least one other of the plurality of dimple sets,   wherein a distance between a first pair of adjacent dimple sets in the plurality of dimple set is different from a distance between a second pair of adjacent dimple sets in the plurality of dimple sets.   
     
     
         12 . The heat exchanger tube of  claim 11 , wherein a distance between adjacent dimple sets of the plurality of dimple sets decreases from the first end to the second end. 
     
     
         13 . The heat exchanger tube of  claim 11 , wherein a distance between adjacent dimple sets of the plurality of dimple sets increases from the first end to the second end. 
     
     
         14 . The heat exchanger tube of  claim 11 , wherein a distance between adjacent dimple sets of the plurality of dimple sets (i) increases from the first end to an inner point located between the first and second ends and (ii) decreases from the inner point to the second end. 
     
     
         15 . The heat exchanger tube of  claim 11 , wherein a distance between adjacent dimple sets of the plurality of dimple sets (i) decreases from the first end to an inner point located between the first and second ends and (ii) increases from the inner point to the second end. 
     
     
         16 . The heat exchanger tube of  claim 11 , wherein:
 the plurality of dimple sets comprises:
 a first section of dimple sets, each dimple set of the first section of dimple sets being adjacent to at least one other dimple set of the first section of dimple sets; and 
 a second section of dimple sets, each dimple set of the second section of dimple sets being adjacent to at least one other dimple set of the second section of dimple sets, 
   each dimple set of the first section of dimple sets has a first common dimple depth, and   each dimple set of the second section of dimple sets has a second common dimple depth that is different from the first common dimple depth.   
     
     
         17 . The heat exchanger tube of  claim 11 , wherein the plurality of dimple sets comprises:
 a first section of dimple sets, wherein:
 each dimple set of the first section of dimple sets is adjacent to at least one other dimple set of the first section of dimple sets; and 
 a rotational angle between adjacent dimple sets of the first section of dimple sets is a first dimple angle; and 
 a rotational angle between adjacent dimple sets of the second section of dimple sets is a second dimple angle that is different from the first dimple angle. 
   
     
     
         18 . A heat exchanger assembly comprising:
 a first heat exchanger tube comprising:
 a first wall having a first inner wall defining a first cavity, a first first end, and a first second end opposite the first first end, the first cavity being configured to direct a first flow of fluid flowing in a direction from the first first end toward the first second end; 
 a plurality of first dimple sets, each first dimple set being located at a corresponding location along a length of the first wall, each of the plurality of first dimple sets comprising:
 one or more first dimples extending inwardly toward the first cavity, each of the one or more first dimples having a dimple depth equal to a radial distance between the first inner wall at the corresponding first dimple of the one or more first dimples and the first inner wall at a non-dimpled location; and 
 
   a second heat exchanger tube comprising:
 a second wall having a second inner wall defining a second cavity, a second first end, and a second second end opposite the second first end, the second cavity being configured to direct a second flow of fluid flowing in a direction from the second first end toward the second second end; 
 a plurality of second dimple sets, each second dimple set being located at a corresponding location along a length of the second wall, each of the plurality of second dimple sets comprising:
 one or more second dimples extending inwardly toward the second cavity, each of the one or more second dimples having a dimple depth equal to a radial distance between the second inner wall at the corresponding second dimple of the one or more second dimples and the second inner wall at a non-dimpled location, 
 
   wherein the second heat exchanger tube has at least one dimple characteristic that is different from a dimple characteristic of the first heat exchanger tube.   
     
     
         19 . The heat exchanger assembly of  claim 18 , wherein the dimple characteristic is at least one of:
 a number of dimple sets;   a longitudinal location of corresponding dimple sets;   a dimple slope;   a distance between adjacent dimple sets;   a dimple depth; or   a dimple angle.