Heat transfer tube for air conditioner application

Abstract

A heat transfer tube and a heat exchanger incorporating at least one heat transfer tube are provided. The heat transfer tube and the heat exchanger are optimized for use within an air conditioner (which is configured to operate only in a cooling mode). The heat transfer tube includes a tube body with an interior surface and an exterior surface. The tube body defining an outer diameter (D o ) and a wall thickness (W T ), wherein a ratio (W T /D o ) the wall thickness (W T ) to the outer diameter (D o ) is between 0.061 and 0.071. The heat transfer tube includes multiple pluralities of adjacent helical fins protruding circumferentially around the interior surface of the tube body at respective helix angles. The multiple pluralities are separated by one or more transition area(s).

What is claimed is: 
     
         1 . A heat transfer tube for operating in a cooling mode, the heat transfer tube comprising:
 a tube body comprising an interior surface and an exterior surface, the tube body defining an outer diameter (D o ) and a wall thickness (W T ), wherein a ratio (W T /D o ) of the wall thickness (W T ) to the outer diameter (D o ) is between 0.061 and 0.071; and   a first plurality of adjacent helical fins protruding circumferentially around the interior surface of the tube body at a first fin helix angle, and a second plurality of adjacent helical fins protruding circumferentially around the interior surface of the tube body at a second fin helix angle, a transition area disposed between the first plurality of adjacent helical fins and the second plurality of adjacent helical fins, each respective helical fin defining a fin height, a fin tip width, a fin base width, and a fin apex angle, at least one groove disposed between the plurality of adjacent helical fins, wherein the interior surface of the tube body further comprises a non-fin weld area, the non-fin weld area defining a non-fin height and a non-fin width.   
     
     
         2 . The heat transfer tube of  claim 1 , wherein each respective helical fin comprises a plurality of crosshatches configured in parallel with a longitudinal axis of the heat transfer tube. 
     
     
         3 . The heat transfer tube of  claim 2 , wherein each respective crosshatch defines at least one of: a crosshatch angle between 0° and 5°, a crosshatch v-angle between 38° and 49°, a crosshatch depth between 0.40 mm and 0.70 mm, a crosshatch pitch between 1.40 mm and 1.60 mm, and a crosshatch width between 0.12 mm and 0.26 mm. 
     
     
         4 . The heat transfer tube of  claim 1 , wherein the heat transfer tube provides a Cavallini factor between 1.67 and 2.22. 
     
     
         5 . The heat transfer tube of  claim 1 , wherein the tube body is comprised of at least one of: an aluminum and an aluminum alloy. 
     
     
         6 . The heat transfer tube of  claim 1 , wherein a cross-section of the heat transfer tube defines between 41 and 48 helical fins. 
     
     
         7 . The heat transfer tube of  claim 1 , wherein the outside diameter is between 6.85 mm and 7.14 mm, and the wall thickness is between 0.410 mm and 0.510 mm. 
     
     
         8 . The heat transfer tube of  claim 1 , wherein the fin height is between 0.144 mm and 0.248 mm, the fin tip width is between 0.096 mm and 0.156 mm, and the fin base width is between 0.18 mm and 0.24 mm. 
     
     
         9 . The heat transfer tube of  claim 1 , wherein the fin apex angle is between 19° and 35°, and the fin helix angles are between 13° and 23°. 
     
     
         10 . The heat transfer tube of  claim 1 , wherein the groove width is between 0.102 mm and 0.221 mm. 
     
     
         11 . A heat exchanger for operating in a cooling mode, the heat exchanger comprising:
 a plurality of fins; and   at least one heat transfer tube configured to pass a fluid therethrough, the at least one heat transfer tube extending through the plurality of fins, each respective heat transfer tube comprising:
 a tube body comprising an interior surface and an exterior surface, the tube body defining an outer diameter (D o ) and a wall thickness (W T ), wherein a ratio (W T /D o ) the wall thickness (W T ) to the outer diameter (D o ) is between 0.061 and 0.071; and 
 a first plurality of adjacent helical fins protruding circumferentially around the interior surface of the tube body at a first fin helix angle, and a second plurality of adjacent helical fins protruding circumferentially around the interior surface of the tube body at a second fin helix angle, a transition area disposed between the first plurality of adjacent helical fins and the second plurality of adjacent helical fins, each respective helical fin defining a fin height, a fin tip width, a fin base width, and a fin apex angle, at least one groove disposed between the plurality of adjacent helical fins, wherein the interior surface of the tube body further comprises a non-fin weld area, the non-fin weld area defining a non-fin height and a non-fin width. 
   
     
     
         12 . The heat exchanger of  claim 11 , wherein each respective helical fin comprises a plurality of crosshatches configured in parallel with a longitudinal axis of the heat transfer tube. 
     
     
         13 . The heat exchanger of  claim 12 , wherein each respective crosshatch defines at least one of: a crosshatch angle between 0° and 5°, a crosshatch v-angle between 38° and 49°, a crosshatch depth between 0.40 mm and 0.70 mm, a crosshatch pitch between 1.40 mm and 1.60 mm, and a crosshatch width between 0.12 mm and 0.26 mm. 
     
     
         14 . The heat exchanger of  claim 11 , wherein the heat transfer tube provides a Cavallini factor between 1.67 and 2.22. 
     
     
         15 . The heat exchanger of  claim 11 , wherein the tube body is comprised of at least one of: an aluminum and an aluminum alloy. 
     
     
         16 . The heat exchanger of  claim 11 , wherein a cross-section of the heat transfer tube defines between 41 and 48 helical fins. 
     
     
         17 . The heat exchanger of  claim 11 , wherein the outside diameter is between 6.85 mm and 7.14 mm, and the wall thickness is between 0.410 mm and 0.510 mm. 
     
     
         18 . The heat exchanger of  claim 11 , wherein the fin height is between 0.144 mm and 0.248 mm, the fin tip width is between 0.096 mm and 0.156 mm, and the fin base width is between 0.18 mm and 0.24 mm. 
     
     
         19 . The heat exchanger of  claim 11 , wherein the fin apex angle is between 19° and 35°, and the fin helix angles are between 13° and 23°. 
     
     
         20 . The heat exchanger of  claim 11 , wherein the groove width is between 0.102 mm and 0.221 mm.