Corrugated tube-in-tube heat exchangers

Abstract

A heat exchanger has an outer tube and an inner tube extending through a lumen of the outer tube. The outer tube has a spiral corrugation and an inner surface of the corrugation contacts or is in proximity to an exterior surface of the inner tube to define a spiral annular channel in an annular space between the inner tube and outer tube.

What is claimed is: 
     
         1 . A tube-in-tube heat exchanger comprising an outer tube and an inner tube extending through a lumen of the outer tube, wherein the outer tube has at least one spiral corrugation and an inner surface of the corrugation contacts or is in proximity to an exterior surface of the inner tube to define a spiral annular channel in an annular space between the inner tube and outer tube. 
     
     
         2 . The tube-in-tube heat exchanger of  claim 1 , wherein the inner tube and outer tube are concentrically arranged. 
     
     
         3 . The tube-in-tube heat exchanger of  claim 1 , wherein the inner tube has at least one spiral corrugation. 
     
     
         4 . The tube-in-tube heat exchanger of  claim 1 , wherein the inner tube is a smooth tube. 
     
     
         5 . The tube-in-tube heat exchanger of  claim 1 , wherein the outer tube has more than one spiral corrugation. 
     
     
         6 . The tube-in-tube heat exchanger of  claim 1 , wherein a pitch of the spiral corrugation is from about 0.25 to about 5. 
     
     
         7 . The tube-in-tube heat exchanger of  claim 1 , wherein a height of the annular channel is about 0.01 inches to about 0.5 inches. 
     
     
         8 . The tube-in-tube heat exchanger of  claim 1 , wherein the inner surface of the corrugation is within 0.02 inches or less of the exterior surface of the inner tube. 
     
     
         9 . The tube-in-tube heat exchanger of  claim 3 , wherein the corrugation of the inner tube is in a direction opposite to the corrugation of the outer tube. 
     
     
         10 . The tube-in-tube heat exchanger of  claim 1 , wherein the inner tube contains an insert that increases turbulence of a fluid flowing inside the inner tube. 
     
     
         11 . The tube-in-tube heat exchanger of  claim 1 , wherein the inner and outer tubes are made from a metal. 
     
     
         12 . The tube-in-tube heat exchanger of  claim 1 , wherein the inner and outer tubes are made from a plastic or elastomer. 
     
     
         13 . The tube-in-tube heat exchanger of  claim 1 , wherein one of the tubes is made from metal and the other from plastic or elastomer. 
     
     
         14 . The tube-in-tube heat exchanger of  claim 1 , wherein the heat exchanger is coiled. 
     
     
         15 . A refrigerant sub-cooler (RSC) for a heat pump comprising the heat exchanger of  claim 1 . 
     
     
         16 . A solution heat exchanger (SHX) for an absorption heat pump comprising the heat exchanger of  claim 1 . 
     
     
         17 . A heat pump comprising the tube-in-tube heat exchanger of  claim 1 , wherein the heat pump is configured to provide a ratio of a pressure loss inside the tube (DELTAP_t) to a pressure loss in the annular channel (DELTAP_a) of 0.9 or less. 
     
     
         18 . A heat pump comprising the tube-in-tube heat exchanger of  claim 1 , wherein a fluid inside the inner tube flows in the same direction as a fluid flowing inside the annular channel. 
     
     
         19 . A heat pump comprising the tube-in-tube heat exchanger of  claim 1 , wherein a fluid inside the inner tube flows in the opposite direction as a fluid flowing inside the annular channel.