Flattened fluid conduits for use in heat exchangers and other systems, and associated methods of manufacture and use

Abstract

Flattened fluid conduits for use in heat exchangers and other systems, and associated methods of manufacture and use are disclosed herein. In one embodiment, the fluid conduit for use in heat exchangers can be manufactured by inserting two or more inner tubes into a circular or at least partially circular barrier tube and at least partially flattening at least some length of the assembly. The heat exchanger conduit can include one or more void spaces within the barrier tube and adjacent to the inner tubes which serve to contain any leaks in the inner tubes and vent any leaks to the atmosphere.

I/we claim: 
     
         1 . A heat exchanger conduit comprising:
 a barrier tube; and   a plurality of fluid-carrying inner tubes nested within the barrier tube, wherein each individual inner tube is in contact with at least one other individual inner tube to create a plurality of isolated voids between the inner tubes and the barrier tube.   
     
     
         2 . The heat exchanger conduit of  claim 1  wherein the individual inner tubes are at least partially flattened. 
     
     
         3 . The heat exchanger conduit of  claim 1  wherein the individual inner tubes have an oval cross-sectional shape. 
     
     
         4 . The heat exchanger conduit of  claim 1  wherein the barrier tube and the plurality of inner tubes are at least partially flattened. 
     
     
         5 . The heat exchanger conduit of  claim 1  wherein at least one of the individual inner tubes has a different diameter than at least one of the other individual inner tubes. 
     
     
         6 . The heat exchanger conduit of  claim 1  wherein at least one of the barrier tube and the plurality of inner tubes has an end portion with a generally circular cross-sectional shape configured to sealably join to an adjacent conduit for fluid communication therebetween. 
     
     
         7 . The heat exchanger conduit of  claim 1  wherein the barrier tube and the plurality of fluid-carrying inner tubes are formed into a coil comprising one or more loops. 
     
     
         8 . The heat exchanger conduit of  claim 1  wherein at least one of the inner tubes includes a plurality of grooves on an interior surface portion thereof. 
     
     
         9 . The heat exchanger conduit of  claim 1  wherein a sidewall portion of the barrier tube protrudes into a sidewall portion of at least one of the inner tubes. 
     
     
         10 . The heat exchanger conduit of  claim 1 , further comprising an insert disposed in at least one of the inner tubes. 
     
     
         11 . The heat exchanger conduit of  claim 1  wherein at least one of the outer barrier tube and fluid-carrying inner tubes is copper. 
     
     
         12 . A heat exchanger comprising:
 an outer sleeve;   a flattened barrier tube disposed within the outer sleeve to define a fluid space therebetween; and   a plurality of flattened inner tubes nested within the barrier tube, wherein each individual inner tube is in contact with the barrier tube and at least one adjacent inner tube.   
     
     
         13 . The heat exchanger of  claim 12  wherein the outer sleeve is corrugated. 
     
     
         14 . The heat exchanger of  claim 12  wherein a sidewall portion of the flattened barrier tube protrudes into a sidewall portion of at least one of the flattened inner tubes. 
     
     
         15 . The heat exchanger of  claim 12  wherein the barrier tube includes a plurality of fins extending outwardly into the fluid space. 
     
     
         16 . The heat exchanger of  claim 12  wherein the fluid space generally surrounds the barrier tube, and wherein the heat exchanger further comprises:
 a first fluid flowing through at least one of the inner tubes; and 
 a second fluid, different than the first fluid, flowing through the fluid space. 
 
     
     
         17 . The heat exchanger of  claim 12 , further comprising at least one turbulator disposed in the fluid space between the barrier tube and the outer sleeve. 
     
     
         18 . A method of manufacturing a heat exchanger conduit comprising:
 disposing a plurality of first tubes within a second tube; and   flattening at least a portion of the second tube whereby each individual tube of the plurality of first tubes contacts the second tube and at least one other individual first tube to create at least one isolated void between the plurality of first tubes and the second tube.   
     
     
         19 . The method of  claim 18 , further comprising flattening the plurality of first tubes within the second tube. 
     
     
         20 . The method of  claim 18 , further comprising disposing the second tube into a sleeve to define an open fluid space therebetween. 
     
     
         21 . The method of  claim 18 , further comprising forming the second tube into a coil comprising one or more loops. 
     
     
         22 . The method of  claim 18 , further comprising forming grooves on an interior surface portion of at least one of the first tubes. 
     
     
         23 . The method of  claim 18 , further comprising forming a plurality of fins on an exterior surface portion of the second tube. 
     
     
         24 . The method of  claim 18 , further comprising twisting at least a portion of the second tube and the plurality of first tubes nested therein.