Interconnected microchannel tube

Abstract

The invention relates to a microchannel tube for use in a heat transfer system. The microchannels have openings in the partitions that separate them from each other, thereby creating many short interconnected passages through which a heat transfer medium will flow in a laminar manner. This permits the liquid and vapor phases of the medium to mix, thereby increasing the efficiency of the system.

1 . A heat transfer tube comprising a sheath formed of copper or a copper alloy and surrounding a plurality of partitions formed from a single metal sheet, the partitions forming microchannels therein through which a heat transfer medium can flow in a laminar manner, the partitions including sidewalls having a plurality of openings therein, with the openings comprising between about 1% to 20% of the area of the partition sidewall such that the heat transfer medium can flow between the microchannels, such that the flow passes between the microchannels without encountering obstructions, thereby avoiding turbulence in the fluid and permitting liquid and vapor phases of the heat transfer medium to mix evenly across the microchannels and entire width of the tube in order to optimize two-phase flow heat transfer through the tube.  
   
   
       2 . The heat transfer tube of  claim 1 , wherein at least 2 to 12 partitions are present so that at least 3 to 13 microchannels are provided.  
   
   
       3 . The heat transfer tube of  claim 1 , wherein at least 4 to 8 partitions are present so that at least 5 to 9 microchannels are provided.  
   
   
       4 . The heat transfer tube of  claim 1 , wherein the partition side walls form a plurality of generally V shaped microchannels.  
   
   
       5 . The heat transfer tube of  claim 1 , wherein each partition has from about 5 openings per 25 mm of length to about 1 opening every 75 mm of length along the length of the partition.  
   
   
       6 . The heat transfer tube of  claim 1 , wherein the openings are not larger than about 80% of the height of the sidewall of the partition.  
   
   
       7 . The heat transfer tube of  claim 1 , wherein the openings are round, oval, or polygonal where each corner of the polygon is rounded to avoid acting as stress raisers.  
   
   
       8 . The heat transfer tube of  claim 7 , wherein the sheet forms serpentine partitions.  
   
   
       9 . The heat transfer tube of  claim 1 , wherein the partition sidewalls are formed of copper or a copper alloy.  
   
   
       10 . The heat transfer tube of  claim 1 , further comprising fins attached to an outer surface of the sheath to assist in transferring heat therefrom.  
   
   
       11 . A heat exchanger comprising two opposing headers and a plurality of the heat transfer tubes according to  claim 1  extending between the headers.  
   
   
       12 . A heat exchanger comprising two opposing headers and a plurality of the heat transfer tubes between the headers, wherein each heat transfer tube of the plurality comprises a sheath formed of aluminum or an aluminum alloy and surrounding a plurality of partitions formed from a single sheet of aluminum or an aluminum alloy, with the partitions forming microchannels therein through which a heat transfer medium can flow can flow in a laminar manner, and the partitions include sidewalls having a plurality of openings therein, with the openings comprising between about 1% to 20% of the area of the partition sidewall such that the heat transfer medium can flow between the microchannels, such that the flow passes between the microchannels without encountering obstructions, thereby avoiding turbulence in the fluid and permitting liquid and vapor phases of the heat transfer medium to mix evenly across the microchannels and entire width of the tube in order to optimize two-phase flow heat transfer through the tube.  
   
   
       13 . The heat exchanger of  claim 12 , wherein each heat transfer tube of the plurality has at least 2 to 12 partitions are present so that at least 3 to 13 microchannels are provided.  
   
   
       14 . The heat exchanger of  claim 12 , wherein each heat transfer tube of the plurality has at least 4 to 8 partitions so that at least 5 to 9 microchannels are provided.  
   
   
       15 . The heat exchanger of  claim 12 , wherein each partition has from about 5 openings per 25 mm of length to about 1 opening every 75 mm of length along the length of the partition.  
   
   
       16 . The heat exchanger of  claim 12 , wherein each partition of the heat transfer tubes of the plurality has openings are not larger than about 80% of the height of the sidewall of the partition.  
   
   
       17 . The heat exchanger of  claim 12 , wherein the openings of each heat transfer tube partition of the plurality are round, oval, or polygonal where each corner of the polygon is rounded to avoid acting as stress raisers.  
   
   
       18 . The heat exchanger of  claim 12 , wherein the sheets used to form each partition of the heat transfer tubes of the plurality form serpentine partitions.  
   
   
       19 . The heat exchanger of  claim 12 , wherein the sheets used to form the each partition of the heat transfer tubes of the plurality are folded to a plurality of generally V shaped microchannels.  
   
   
       20 . The heat exchanger of  claim 12 , wherein the each heat transfer tube of the plurality has fins attached to an outer surface of its respective sheath to assist in transferring heat therefrom.