Method of and apparatus for transferring heat energy between a heat exchanging subsystem above the surface of the earth and material therebeneath using one or more coaxial-flow heat exchanging structures producing turbulence in aqueous-based heat-transfering fluid flowing along helically-extending outer flow channels formed therein

Abstract

A method of and apparatus for transferring heat energy between a heat exchanging subsystem installed above the surface of the Earth, and material beneath the surface of the Earth, by installing one or more coaxial-flow heat exchanging structures in the material beneath the surface of the Earth. Each coaxial-flow heat exchanging structure has inner and out flow channels along which aqueous-based heat transfer fluid is circulated. Turbulence is generated in the aqueous-based heat transfer fluid flowing along the outer flow channel, to increase the rate of heat energy transfer between the aqueous-based heat transfer fluid and material beneath the surface of the Earth along the length of the outer flow channel.

1 . A method of transferring heat energy between a heat exchanging subsystem installed above the surface of the Earth, and material beneath the surface of the Earth, said method comprising the steps:
 (a) installing said heat exchanging subsystem above the surface of the Earth, wherein said heat exchanging subsystem has a first heat exchanger for supporting the flow of a heat conducting stream through said first heat exchanger, and a second heat exchanger for supporting the flow of an aqueous-based heat transfer fluid through said second heat exchanger, wherein said first heat exchanger and said second heat exchanger are arranged in a heat transfer relationship with each other;   (b) installing one or more coaxial-flow heat exchanging structures in the material beneath the surface of said Earth, wherein each said coaxial-flow heat exchanging structure includes:   a proximal end and a distal end;   an input port, provided at the proximal end, and an output port, provided at the proximal end;   an inner tube section having an outer wall surface extending between said proximal and distal ends, and said inner tube section supporting an inner flow channel having a substantially uniform inner diameter along its length between said proximal and distal ends;   a thermally conductive outer tube section, disposed coaxially around said inner tube section, and having an inner wall surface extending between said proximal and distal ends, and sealed off at said distal end to prevent fluid leaks from occurring at said distal end;   wherein an outer flow channel of annulus geometry is formed between the outer wall surface of said inner tube section and the inner wall surface of said thermally conductive outer tube section;   wherein multiple helically-arranged fins are disposed along a substantial portion of the length of said outer flow channel of annulus geometry so as to form multiple helically-extending outer flow channels having cross-sectional dimensions and disposed between said inner tube section and said thermally conductive outer tube section;   (c) arranging said input and output ports of each said coaxial-flow heat exchanging structure in fluid communication with said second heat exchanger so that said second heat exchanger is in fluid communication with said inner flow channel and said helically-extending outer flow channels of each said coaxial-flow heat exchanging structure;   (d) filling said second heat exchanger and said inner flow channel and said helically-extending outer flow channels of each said coaxial-flow heat exchanging structure, with a predetermined volume of aqueous-based heat transfer fluid; and   (e) circulating said predetermined volume of aqueous-based heat transfer fluid so that:
 (1) said aqueous-based heat transfer fluid flows out of said second heat exchanger and into said input port at a first temperature, and then flows down along said inner flow channel in a substantially laminar manner, and then around said distal end, and then flows along said helically-extending outer flow channels and out of said output port and back into said second heat exchanger at a second temperature, in a closed-loop fashion, sealed off from the material beneath the surface of said Earth; 
 (2) said multiple helically-extending outer flow channels generate turbulence in the aqueous-based heat transfer fluid flowing along said helically-extending outer flow channels, thereby disturbing the formation of boundary layers along the inner surface of said thermally conductive outer tube section, and increasing the transfer of heat energy between said aqueous-based heat transfer fluid flowing along said helically-extending outer flow channels and the inner surface of said thermally conductive outer tube section; and 
 (3) the heat transfer process occurring between said aqueous-based heat transfer fluid and the material beneath the surface of said Earth is carried out without a change in state of said aqueous-based heat transfer fluid flowing within and along said inner flow channel and said helically-extending outer flow channels of each said coaxial-flow heat exchanging structure. 
   
     
     
         2 . The method of  claim 1 , wherein said heat exchanging subsystem is a refrigeration system and said heat conducting stream is a refrigerant flowing through said refrigeration system. 
     
     
         3 . The method of  claim 1 , wherein said heat exchanging subsystem is a heating or cooling coil unit and said heat conducting stream is a heat conducting fluid flowing through said heating or cooling coil unit. 
     
     
         4 . The method of  claim 1 , wherein said multiple helically-arranged fins are mounted to the outer surface of said inner tube section. 
     
     
         5 . The method of  claim 1 , wherein said multiple helically-arranged fins are continuous along said outer flow channel of annulus geometry. 
     
     
         6 . The method of  claim 1 , wherein the flow of said aqueous-based heat transfer fluid in a substantially laminar manner provides an insulating effect between said inner flow channel and said helically-extending outer flow channels. 
     
     
         7 . The method of  claim 1 , which enables sinking of heat energy into the material beneath the surface of the Earth during cooling operations, or the sourcing of heat energy from the material beneath the surface of the Earth during heating operations. 
     
     
         8 . The method of  claim 1 , wherein step (b) comprises:
 (i) for each coaxial-flow heat exchanging structure, drilling a bore into the Earth;   (ii) installing said coaxial-flow heat exchanging structure into said bore; and   (iii) thermally-cementing said thermally conductive outer tube section of said coaxial-flow heat exchanging structure into said bore.   
     
     
         9 . The method of  claim 1 , wherein said multiple helically-arranged fins are arranged at a predetermined pitch. 
     
     
         10 . The method of  claim 1 , wherein said aqueous-based heat transfer fluid includes a heat transfer enhancing additive. 
     
     
         11 . The method of  claim 10 , wherein said heat transfer enhancing additive is selected from the group consisting of biodegradable anti-freeze additives, and micron-sized particles for increasing the heat capacity of said aqueous-based heat transfer fluid. 
     
     
         12 . A method of transferring heat energy between a heat exchanging subsystem installed above the surface of the Earth, and material beneath the surface of the Earth, said method comprising the steps:
 (a) installing said heat exchanging subsystem above the surface of the Earth, wherein said heat exchanging subsystem has a first heat exchanger for supporting the flow of a heat conducting stream through said first heat exchanger, and a second heat exchanger for supporting the flow of an aqueous-based heat transfer fluid through said second heat exchanger, wherein said first heat exchanger and said second heat exchanger are arranged in a heat transfer relationship with each other;   (b) installing one or more coaxial-flow heat exchanging structures in the material beneath the surface of said Earth, wherein each said coaxial-flow heat exchanging structure includes:   a proximal end and a distal end;   an input port, provided at the proximal end, and an output port, provided at the proximal end;   an inner tube section having an outer wall surface extending between the said proximal and distal ends, and said inner tube section supporting an inner flow channel having a substantially uniform inner diameter along its length between said proximal and distal ends;   a thermally conductive outer tube section, disposed coaxially around said inner tube section, and having an inner wall surface extending between said proximal and distal ends, and sealed off at said distal end to prevent fluid leaks from occurring at said distal end;   wherein an outer flow channel of annulus geometry is formed between the outer wall surface of said inner tube section and the inner wall surface of said thermally conductive outer tube section;   wherein multiple helically-arranged fins are disposed along a substantial portion of the length of said outer flow channel of annulus geometry so as to form multiple helically-extending outer flow channels having cross-sectional dimensions and disposed between said inner tube section and said thermally conductive outer tube section;   (c) arranging said input and output ports of each said coaxial-flow heat exchanging structure in fluid communication with said second heat exchanger so that second heat exchanger in fluid communication with said inner flow channel and said helically-extending outer flow channels of each said coaxial-flow heat exchanging structure;   (d) filling said second heat exchanger and said inner flow channel and said helically-extending outer flow channels of each said coaxial-flow heat exchanging structure, with a predetermined volume of aqueous-based heat transfer fluid; and   (e) circulating said predetermined volume of aqueous-based heat transfer fluid so that:
 (1) said aqueous-based heat transfer fluid flows out of said second heat exchanger and into said input port at a first temperature, and then flows down along said helically-extending outer flow channels, and then around said distal end, and then flows along said inner flow channel in a substantially laminar manner and out of said output port and back into said second heat exchanger at a second temperature, in a closed-loop fashion, sealed off from the material beneath the surface of said Earth; 
 (2) said multiple helically-extending outer flow channels generate turbulence in the aqueous-based heat transfer fluid flowing along said helically-extending outer flow channels, thereby disturbing the formation of boundary layers along the inner surface of said thermally conductive outer tube section, and increasing the transfer of heat energy between said aqueous-based heat transfer fluid flowing along said helically-extending outer flow channels and the inner surface of said thermally conductive outer tube section; and 
 (3) the heat transfer process occurring between said aqueous-based heat transfer fluid and the material beneath the surface of said Earth is carried out without a change in state of said aqueous-based heat transfer fluid flowing within and along said inner flow channel and said helically-extending outer flow channels of each said coaxial-flow heat exchanging structure. 
   
     
     
         13 . The method of  claim 12 , wherein said heat exchanging subsystem is a refrigeration system and said heat conducting stream is a refrigerant flowing through said refrigeration system. 
     
     
         14 . The method of  claim 12 , wherein said heat exchanging subsystem is a heating or cooling coil unit and said heat conducting stream is a heat conducting fluid flowing through said heating or cooling coil unit. 
     
     
         15 . The method of  claim 12 , wherein said multiple helically-arranged fins are mounted to the outer surface of said inner tube section. 
     
     
         16 . The method of  claim 12 , wherein said multiple helically-arranged fins are continuous along said outer flow channel of annulus geometry. 
     
     
         17 . The method of  claim 12 , wherein the flow of said aqueous-based heat transfer fluid in a substantially laminar manner provides an insulating effect between said inner flow channel and said helically-extending outer flow channels. 
     
     
         18 . The method of  claim 12 , which enables sinking of heat energy into the material beneath the surface of the Earth during cooling operations, or the sourcing of heat energy from the material beneath the surface of the Earth during heating operations. 
     
     
         19 . The method of  claim 12 , wherein step (b) comprises:
 (i) for each said coaxial-flow heat exchanging structure, drilling a bore into the Earth;   (ii) installing said coaxial-flow heat exchanging structure into said bore; and   (iii) thermally-cementing said thermally conductive outer tube section of said coaxial-flow heat exchanging structure into said bore.   
     
     
         20 . The method of  claim 19 , wherein said multiple helically-arranged fins are arranged at a predetermined pitch. 
     
     
         21 . The method of  claim 12 , wherein said aqueous-based heat transfer fluid includes a heat transfer enhancing additive. 
     
     
         22 . The method of  claim 21 , wherein said heat transfer enhancing additive is selected from the group consisting of biodegradable anti-freeze additives, and micron-sized particles for increasing the heat capacity of said aqueous-based heat transfer fluid. 
     
     
         23 . Apparatus for transferring heat energy transfer between a heat exchanging subsystem installed above the surface of the Earth, and material beneath the surface of the Earth, said apparatus comprising:
 said heat exchanging subsystem installed above the surface of the Earth, and including a first heat exchanger for supporting the flow of a heat conducting stream through said first heat exchanger, and a second heat exchanger for supporting the flow of an aqueous-based heat transfer fluid through said second heat exchanger, wherein said first heat exchanger and said second heat exchanger are arranged in a heat transfer relationship with each other;   one or more coaxial-flow heat exchanging structures installed in the material beneath the surface of said Earth,   wherein each said coaxial-flow heat exchanging structure includes:   a proximal end and a distal end;   an input port, provided at the proximal end, and an output port, provided at the proximal end;   an inner tube section having an outer wall surface extending between said proximal and distal ends, and said inner tube section supporting an inner flow channel having a substantially uniform inner diameter along its length between said proximal and distal ends;   a thermally conductive outer tube section, disposed coaxially around said inner tube section, and having an inner wall surface extending between said proximal and distal ends, and sealed off at said distal end to prevent fluid leaks from occurring at said distal end;   wherein an outer flow channel of annulus geometry is formed between the outer wall surface of said inner tube section and the inner wall surface of said thermally conductive outer tube section;   wherein multiple helically-arranged fins are disposed along a substantial portion of the length of said outer flow channel of annulus geometry so as to form multiple helically-extending outer flow channels having cross-sectional dimensions and being disposed between said inner tube section and said thermally conductive outer tube section;   said input and output ports of each said coaxial-flow heat exchanging structure being arranged in fluid communication with said second heat exchanger so that said second heat exchanger is in fluid communication with said inner flow channel and said helically-extending outer flow channels of each said coaxial-flow heat exchanging structure;   said second heat exchanger and said inner flow channel and said helically-extending outer flow channels of each said coaxial-flow heat exchanging structure being filled with a predetermined volume of aqueous-based heat transfer fluid;   one or more pumps for circulating said predetermined volume of aqueous-based heat transfer fluid so that said aqueous-based heat transfer fluid flows out of said second heat exchanger and into said input port at a first temperature, and then flows down along said inner flow channel in a substantially laminar manner, and then around said distal end, and then flows along said helically-extending outer flow channels and out of said output port and back into said second heat exchanger at a second temperature, in a closed-loop fashion, sealed off from the material beneath the surface of said Earth;   wherein said multiple helically-extending outer flow channels generate turbulence in the aqueous-based heat transfer fluid flowing along said helically-extending outer flow channels, thereby disturbing the formation of boundary layers along the inner surface of said thermally conductive outer tube section, and increasing the transfer of heat energy between said aqueous-based heat transfer fluid flowing along said helically-extending outer flow channels and the inner surface of said thermally conductive outer tube section; and   wherein the transfer of heat energy occurring between said aqueous-based heat transfer fluid and the material beneath the surface of said Earth is carried out without a change in state of said aqueous-based heat transfer fluid flowing within and along said inner flow channel and said helically-extending outer flow channels of each said coaxial-flow heat exchanging structure.   
     
     
         24 . The apparatus of  claim 23 , wherein said heat exchanging subsystem is a refrigeration system and said heat conducting stream is a refrigerant flowing through said refrigeration system. 
     
     
         25 . The apparatus of  claim 23 , wherein said heat exchanging subsystem is a heating or cooling coil unit and said heat conducting stream is a heat conducting fluid flowing through said heating or cooling coil unit. 
     
     
         26 . The apparatus of  claim 23 , wherein said multiple helically-arranged fins are mounted to the outer surface of said inner tube section. 
     
     
         27 . The apparatus of  claim 23 , wherein said multiple helically-arranged fins are continuous along said outer flow channel of annulus geometry. 
     
     
         28 . The apparatus of  claim 23 , wherein the flow of said aqueous-based heat transfer fluid in a substantially laminar manner provides an insulating effect between said inner flow channel and said helically-extending outer flow channels. 
     
     
         29 . The apparatus of  claim 23 , which enables sinking of heat energy into the material beneath the surface of the Earth during cooling operations, or the sourcing of heat energy from the material beneath the surface of the Earth during heating operations. 
     
     
         30 . The apparatus of  claim 23 , wherein said thermally conductive outer tube section of said coaxial-flow heat exchanging structure is thermally-cemented into said bore. 
     
     
         31 . The apparatus of  claim 23 , wherein said multiple helically-arranged fins are arranged at a predetermined pitch. 
     
     
         32 . The apparatus of  claim 23 , wherein said aqueous-based heat transfer fluid includes a heat transfer enhancing additive. 
     
     
         33 . The apparatus of  claim 32 , wherein said heat transfer enhancing additive is selected from the group consisting of biodegradable anti-freeze additives, and micron-sized particles for increasing the heat capacity of said aqueous-based heat transfer fluid. 
     
     
         34 . An apparatus for transferring heat energy between a heat exchanging subsystem installed above the surface of the Earth, and material beneath the surface of the Earth, said apparatus comprising:
 said heat exchanging subsystem installed above the surface of the Earth, wherein said heat exchanging subsystem has a first heat exchanger for supporting the flow of a heat conducting stream through said first heat exchanger, and a second heat exchanger for supporting the flow of an aqueous-based heat transfer fluid through said second heat exchanger, wherein said first heat exchanger and said second heat exchanger are arranged in a heat transfer relationship with each other;   one or more coaxial-flow heat exchanging structures installed in the material beneath the surface of said Earth, wherein each said coaxial-flow heat exchanging structure includes:   a proximal end and a distal end;   an input port, provided at the proximal end, and an output port, provided at the proximal end;   an inner tube section having an outer wall surface extending between the said proximal and distal ends, and said inner tube section supporting an inner flow channel having a substantially uniform inner diameter along its length between said proximal and distal ends;   a thermally conductive outer tube section, disposed coaxially around said inner tube section, and having an inner wall surface extending between said proximal and distal ends, and sealed off at said distal end to prevent fluid leaks from occurring at said distal end;   wherein an outer flow channel of annulus geometry is formed between the outer wall surface of said inner tube section and the inner wall surface of said thermally conductive outer tube section;   wherein multiple helically-arranged fins are disposed along a substantial portion of the length of said outer flow channel of annulus geometry so as to form multiple helically-extending outer flow channels having cross-sectional dimensions and disposed between said inner tube section and said thermally conductive outer tube section;   said input and output ports of each said coaxial-flow heat exchanging structure being arranged in fluid communication with said second heat exchanger so that said second heat exchanger is in fluid communication with said inner flow channel and said helically-extending outer flow channels of each said coaxial-flow heat exchanging structure;   said second heat exchanger and said inner flow channel and said helically-extending outer flow channels of each said coaxial-flow heat exchanging structure being filled with a predetermined volume of aqueous-based heat transfer fluid; and   one or more pumps for circulating said predetermined volume of aqueous-based heat transfer fluid so that said aqueous-based heat transfer fluid flows out of said second heat exchanger and into said input port at a first temperature, and then flows down along said helically-extending outer flow channels, and then around said distal end, and then flows along said inner flow channel in a substantially laminar manner and out of said output port and back into said second heat exchanger at a second temperature, in a closed-loop fashion, sealed off from the material beneath the surface of said Earth;   wherein said multiple helically-extending outer flow channels generate turbulence in the aqueous-based heat transfer fluid flowing along said helically-extending outer flow channels, thereby disturbing the formation of boundary layers along the inner surface of said thermally conductive outer tube section, and increasing the transfer of heat energy between said aqueous-based heat transfer fluid flowing along said helically-extending outer flow channels and the inner surface of said thermally conductive outer tube section; and   wherein the transfer of heat energy occurring between said aqueous-based heat transfer fluid and the material beneath the surface of said Earth is carried out without a change in state of said aqueous-based heat transfer fluid flowing within and along said inner flow channel and said helically-extending outer flow channels of each said coaxial-flow heat exchanging structure.   
     
     
         35 . The apparatus of  claim 34 , wherein said heat exchanging subsystem is a refrigeration system and said heat conducting stream is a refrigerant flowing through said refrigeration system. 
     
     
         36 . The apparatus of  claim 34 , wherein said heat exchanging subsystem is a heating or cooling coil unit and said heat conducting stream is a heat conducting fluid flowing through said heating or cooling coil unit. 
     
     
         37 . The apparatus of  claim 34 , wherein said multiple helically-arranged fins are mounted to the outer surface of said inner tube section. 
     
     
         38 . The apparatus of  claim 34 , wherein said multiple helically-arranged fins are continuous along said outer flow channel of annulus geometry. 
     
     
         39 . The apparatus of  claim 34 , wherein the flow of said aqueous-based heat transfer fluid in a substantially laminar manner provides an insulating effect between said inner flow channel and said helically-extending outer flow channels. 
     
     
         40 . The apparatus of  claim 34 , which enables sinking of heat energy into the material beneath the surface of the Earth during cooling operations, or the sourcing of heat energy from the material beneath the surface of the Earth during heating operations. 
     
     
         41 . The apparatus of  claim 34 , wherein said thermally conductive outer tube section of each said coaxial-flow heat exchanging structure is thermally-cemented into a bore drilled in the earth. 
     
     
         42 . The apparatus of  claim 34 , wherein said multiple helically-arranged fins are arranged at a predetermined pitch. 
     
     
         43 . The apparatus of  claim 34 , wherein said aqueous-based heat transfer fluid includes a heat transfer enhancing additive. 
     
     
         44 . The apparatus of  claim 43 , wherein said heat transfer enhancing additive is selected from the group consisting of biodegradable anti-freeze additives, and micron-sized particles for increasing the heat capacity of said aqueous-based heat transfer fluid.