Coaxial-flow heat transfer structure

Abstract

An coaxial-flow heat exchanging structure having a proximal end and a distal end for exchanging heat between a source of fluid at a first temperature and the environment (e.g. air, ground, water, slurry etc.) at a second temperature. The coaxial-flow heat transfer structure comprises: a thermally conductive outer tube section, and an inner tube section having an inner flow channel and being coaxially arranged within the outer tube section. An outer flow channel is formed between the inner and outer tube sections, and helically-extending turbulence generator is provided along the outer flow channel, so as to create turbulence along the flow of heat exchanging fluid flowing between the inner and outer flow channels, and thereby increasing the heat transfer through the walls of the outer tube section to the ambient environment.

1 . A coaxial-flow heat transferring structure for installation in an ambient environment and facilitating the transfer of heat energy between an external heat energy producing system and said ambient environment, comprising:
 a proximal end and a distal end for exchanging heat between a source of fluid at a first temperature and the environment at a second temperature;   an input port, provided at the proximal end, for receiving a heat (energy) transferring fluid at a first temperature from an external heat energy producing system, and an output port, provided at the proximal end, for outputting said heat transferring fluid at a second temperature to the heat energy producing system;   an inner tube section having an outer wall surface extending between the proximal and distal ends, and supporting an inner flow channel having a substantially uniform inner diameter along its length and into which the heat exchanging fluid can be introduced from the input port and along which the heat exchanging fluid can flow in a substantially laminar manner towards said distal end;   an outer tube section, disposed coaxially around the inner tube section, and having an inner wall surface extending between said proximal and distal ends, and the outer tube section being in thermal communication with the ambient environment;   wherein an outer flow channel is provided between the outer wall surface of the inner tube section and the inner wall surface of the outer tube section, and capable of conducting heat exchanging fluid from the distal extend, along the outer flow channel towards the proximal end, and exiting from the second port; and   wherein a turbulence generating structure is disposed along a substantial portion of the length of the outer flow channel so as to introduce turbulence into the flow of said heat exchanging fluid flowing along the outer flow channel, from the distal end towards the proximal end, and thereby improving the transfer of heat energy between the heat exchanging fluid and the ambient environment along the length of the outer flow channel.   
     
     
         2 . The coaxial-flow heat exchanging structure of  claim 1 , wherein the turbulence generating structure comprises a helically arranged fin structure disposed along a substantial portion of the outer flow channel. 
     
     
         3 . The coaxial-flow heat exchanging structure of  claim 3 , wherein the helically arranged fin structure is mounted to the outer surface of the inner tube section. 
     
     
         4 . The coaxial-flow heat exchanging structure of  claim 1  wherein the laminar fluid flow along the inner tube section provides an insulating effect between the wall of the inner tube section and the inner flow channel. 
     
     
         5 . The coaxial-flow heat exchanging structure of  claim 1 , for sinking heat into the ground during cooling operations, or sourcing heat from the ground during heating operations. 
     
     
         6 . The coaxial-flow heat exchanging structure of  claim 1 , wherein the coaxial-flow heat exchanging structure functions as a primary system, a system sub-component, or a sub-component kit of the heat pump system. 
     
     
         7 . The coaxial-flow heat exchanging structure of  claim 1 , wherein said thermally-conductive outer tube has an outer heat exchanging surface area which is increased by fluting the surface thereof. 
     
     
         8 . The coaxial-flow heat exchanging structure of  claim 1 , wherein said thermally conductive outer tube section is thermally-cemented into a bore drilled in the Earth. 
     
     
         9 . The coaxial-flow heat exchanging structure of  claim 8 , wherein said bore extends through an aquifer. 
     
     
         10 . The coaxial-flow heat-transfer structure of  claim 8 , wherein the temperature of the heat transfer fluid is substantially maintained until it reaches the bottom of the bore, so that a higher temperature difference is maintained between the turbulent flowing fluid in said helical flow channel, thereby increasing the rate of heat transfer into the inside wall of said outer tube section and consequently into the Earth, rock, and aquifer, if an aquifer exists. 
     
     
         11 . A coaxial-flow heat transfer system comprising:
 a thermally-conductive outer tube section, and   an inner tube section having an inner flow channel having a substantially uniform inner diameter along its entire length and being coaxially installed within said outer tube section supporting helically-arranged turbulence generator fins on the outer surface of said inner tube section, so as to form at least one helically-extending outer flow channel between said inner and outer tube sections, so that heat energy contained within a heat exchanging fluid flowing down said inner flow channel and along the helically-arranged outer flow channel, is exchanged through the walls of said outer tube section and into the ambient environment.