System and method for geothermal conduit loop in-ground installation and soil penetrating head therefor

Abstract

A geothermal in-ground conduit system and a method of constructing and installing same are described. The system comprises at least one loop of flexible tubing adapted to convect a heat exchange liquid therein. The loop has a lower end section and opposed spaced-apart elongated side sections communicating with one another. The lower end section is retained in a soil penetrating head. The soil penetrating head has a leading soil penetrating and ramming face formation. A force transmitting shaft is engageable with the soil penetrating head for transmitting a pushing force against the soil penetrating head to displace same in the soil while pulling the loop and guiding the loop into the soil as the penetrating face forms passages for permanent burial of at least a major portion of the loop together with the soil penetrating head, or the soil penetrating head can be retracted.

1 . A geothermal in-ground conduit system comprising at least one loop of tubing material adapted to convect a heat exchange liquid therein, said loop having a lower end section and opposed spaced apart elongated side sections communicating with said lower end section to form said loop, said lower end section being adapted to be driven in soil for permanent burial therein with at least a major portion of said side sections and in direct contact with the soil for heat exchange therewith. 
     
     
         2 . A geothermal in-ground conduit system as claimed in  claim 1 , wherein said lower end section is retained in a soil penetrating head, said soil penetrating head having a leading soil penetrating face formation, coupling means to receive a force transmitting shaft for transmitting a pushing force against said soil penetrating head to displace said soil penetrating head in the soil while pulling said loop and guiding said loop into the soil as said soil penetrating head forms passages in the soil. 
     
     
         3 . A geothermal in-ground conduit system as claimed in  claim 2  wherein said soil penetrating head also has a ramming face formation, said ramming face formation having a convex shaped forward sharp edge and opposed symmetrically shaped bowed side walls extending outwardly from an apex of said convex forward sharp edge. 
     
     
         4 . A geothermal in-ground conduit system as claimed in  claim 3  wherein said coupling means is secured to said soil penetrating head and accessible from a rear end of said soil penetrating head, said coupling means being secured between said symmetrically curved, shaped side walls and being positioned to maintain said force transmitting shaft along a straight central axis passing through said apex and at mid-length of said opposed symmetrically shaped side walls. 
     
     
         5 . A geothermal in-ground conduit system as claimed in  claim 4  wherein said coupling means is a hollow tube section dimensioned to receive a free lower end of said force transmitting shaft therein. 
     
     
         6 . A geothermal in-ground conduit system as claimed in  claim 4  wherein said coupling means is a tubular connector having engageable formations for detachable connection with further engageable formations at a free lower end of said force transmitting shaft. 
     
     
         7 . A geothermal in-ground conduit system as claimed in  claim 6  wherein said engageable formations and further engageable formations are screw thread formations. 
     
     
         8 . A geothermal in-ground conduit system as claimed in  claim 4  wherein said coupling means is a hollow coupling tube, said hollow coupling tube being connected in communication with said lower end section and said opposed side sections, said coupling tube having connection means for sealing engagement with a free lower end of said force transmitting shaft, said force transmitting shaft being a hollow shaft for convecting the heat exchange liquid therein and into said opposed side sections of said loop through said lower end section. 
     
     
         9 . A geothermal in-ground conduit system as claimed in  claim 2  wherein at least said side sections of said loop are formed of flexible plastic material, said lower end section is retained in a curved retention passage of said soil penetrating head with said opposed spaced-apart side section extending rearwardly of said soil penetrating head. 
     
     
         10 . A geothermal in-ground conduit system as claimed in  claim 2  wherein said lower end section of said loop is constituted by a curved conduit secured in said soil penetrating head, said curved conduit having opposed free ends, and means to immovably and sealingly connect said opposed spaced-apart side sections of said loop to a respective one of said opposed free ends of said curved conduit. 
     
     
         11 . A geothermal in-ground conduit system as claimed in  claim 2  wherein there are two of said loops of flexible tubing having their lower end section secured to said soil penetrating head, said two of said loops extending at substantially right angle to one another. 
     
     
         12 . A geothermal in-ground conduit system as claimed in  claim 11  wherein said coupling means is a hollow coupling tube, said hollow coupling tube being connected to each said opposed spaced-apart side section of said two loops and forming said lower end section of each said two of said loops, said coupling tube having connection means for sealing engagement with a free lower end of said force transmitting shaft, said force transmitting shaft being a hollow shaft for convecting the heat exchange liquid therein and into said opposed side sections of each said two of said loops, said hollow shaft having an internal transverse sectional area equal to the totality of the internal transverse sectional area of said opposed side sections of said two of said loops. 
     
     
         13 . A geothermal in-ground conduit system as claimed in  claim 2  wherein said spaced-apart side sections have a free top end, a coupling connector sealingly secured to said free top end for connecting two or more of said loops in series to form a closed loop assembly. 
     
     
         14 . A geothermal in-ground conduit system as claimed in  claim 2  wherein there is further provided spacer means securable to said force transmitting shaft and displaceable therewith, said spacer means having opposed projecting arms axially aligned and extending transversely of said force transmitting shaft for supporting a guide tube at opposed free ends thereof, each said guide tubes receiving a respective one of said spaced-apart side sections of said flexible tube therethrough to maintain said side sections of said flexible tube spaced apart as they are drawn into the soil, said opposed projecting arms being shaped for ease of penetration in the soil. 
     
     
         15 . A geothermal in-ground conduit system as claimed in  claim 14  wherein said force transmitting shaft is constituted by a plurality of end-to-end interconnected pipe sections, said spacer means having a pipe hub connector adapted to be secured at selected ones of end interconnections of said pipes. 
     
     
         16 . A geothermal in-ground conduit system as claimed in  claim 2  wherein said force transmitting shaft is a solid shaft of hard material sufficient to constitute a pile to add support of a building structure foundation after said soil penetrating head has been driven into said soil to contact bedrock or dense soil, and connection means to immovably secure a top end section of said force transmitting shaft to said foundation. 
     
     
         17 . A geothermal in-ground conduit system as claimed in  claim 3  wherein said soil penetrating head is formed from one of steel or high density plastics material having a forward cutting blade secured along said convex forward cutting edge. 
     
     
         18 . A geothermal in-ground conduit system as claimed in  claim 2  wherein there are two or more of said loops of flexible tubing, said loops being interconnected in series with one another to form a closed-loop tubular conduit circuit having a pair of tube open end sections for connection to heat exchange means for circulating the heat exchange liquid in said tubular circuit, and a footing of a building foundation formed over said closed-loop circuit or at least a portion thereof with said pair of tube open end sections accessible from inside foundation walls formed over said footing. 
     
     
         19 . A geothermal in-ground conduit system as claimed in  claim 18  wherein said pair of tube open end sections extend through a respective insulated protective sleeve about which concrete is poured and set to form said footing. 
     
     
         20 . A geothermal in-ground conduit system as claimed in  claim 2  wherein said coupling means is coupled to a composite force transmitting shaft comprised of two or more shaft sections interconnected end-to-end by disconnectable means; said pushing force being applied against a free top end of each said two or more shaft sections one after another as they are driven into the soil from inside a pre-formed foundation through a hole formed in a concrete foundation floor or wall, by a pneumatic force applying device secured to an inner surface of a concrete foundation wall or floor. 
     
     
         21 . A geothermal in-ground conduit system as claimed in  claim 20  wherein said pneumatic force applying device is constituted by a pair of pneumatic pistons each having a piston cylinder and a piston rod, said cylinders being coupled together in spaced, side-by-side parallel relationship by a force transmission shaft engaging assembly, said piston rods having piston rod ends being secured to a foundation anchor plate immovably secured to said inner surface of said foundation wall or floor in proximity to said hole. 
     
     
         22 . A geothermal in-ground conduit system as claimed in  claim 21  wherein said shaft engaging assembly is comprised of an attachment frame immovably secured to said cylinder to maintain said cylinders in said spaced-apart parallel relationship, a pair of clamping jaws slidingly displaceable on a respective angulated slide plate, said slide plates being retained in spaced-apart facial relationship to support said clamping jaws in a spaced-apart facial relationship to define a shaft passage therebetween extending parallel to said cylinders; said clamping jaws, when at a lower end of said slide plates, being spaced further away from one another to define a non-engaging position with said shaft when positioned in said shaft passage; said clamping jaws when moving to an upper end of said slide plates by downward displacement of said cylinders converging towards one another and clamping said shaft in said shaft passage to impart said pushing force on said shaft and said soil penetrating head. 
     
     
         23 . A geothermal in-ground conduit system as claimed in  claim 22  wherein said attachment frame further comprises a first bridge plate extending between said cylinders, an aperture in said first bridge plate for receiving said shaft in close sliding fit therein, and a further bridge plate secured between said cylinders and spaced above said first bridge plate, guide means formed with said further bridge plate and aligned with said aperture whereby to position and guide said shaft intermediate said cylinders and in substantially parallel relationship therewith. 
     
     
         24 . A geothermal in-ground conduit system as claimed in  claim 22  wherein said clamping jaws are caused to move to a lower end of said slide plates to said non-engaging position by upward displacement of said cylinders. 
     
     
         25 . A geothermal in-ground conduit system as claimed in  claim 21  wherein said foundation anchor plate is temporarily secured to said inner surface of said foundation wall or floor in proximity to said foundation wall by anchor bolts, said anchor plate having a pair of connecting elements for securement of said piston rod ends thereto. 
     
     
         26 . A geothermal in-ground conduit system as claimed in  claim 25  wherein said anchor plate is secured at a desired angle to direct said soil penetrating head and loop of flexible tubing in a desired angular direction in said soil. 
     
     
         27 . A geothermal in-ground conduit system as claimed in  claim 2  wherein said soil penetrating head is comprised by a pair of spaced apart interconnected side walls, said side walls being interconnected together by an internal recessed tube abutment member, a channel defined between said side walls in an outer peripheral portion thereof along opposed side edges and a leading edge thereof to receive said lower end section and an immediate lower, portion of said elongated side sections therein, said tube abutment member having an outer seating wall configured to receive said lower en section of said loop in facial contact therewith, and means to receive a force transmitting shaft to a rear section of said soil penetrating head. 
     
     
         28 . A geothermal in-ground conduit system as claimed in  claim 27  wherein said lower section of said loop is a U-shaped curved section, said outer seating wall having a convexly curved leading portion. 
     
     
         29 . A geothermal in-ground conduit system as claimed in  claim 28  wherein at least said side sections of said loop are formed of flexible plastic material. 
     
     
         30 . A geothermal in-ground conduit system as claimed in  claim 28  wherein said lower end section of said loop is formed of rigid material. 
     
     
         31 . A geothermal in-ground conduit system as claimed in  claim 27  wherein said force transmitting shaft is detachably connected to said rear section of said soil penetrating head for retraction of said force transmitting shaft after said head and loop of tubing has been driven to a desired depth in the soil. 
     
     
         32 . A geothermal in-ground conduit system as claimed in  claim 27  wherein said force transmitting shaft is connected to said rear section of said soil penetrating hear for retraction of said soil penetrating head after said head has driven said loop to a desired depth in the soil. 
     
     
         33 . A geothermal in-ground conduit system as claimed in  claim 27  wherein a soil penetrating nose member is detachably connected to said leading edge of said side walls for ease of penetration of said soil penetrating head and protection of said lower end section of said loop. 
     
     
         34 . A geothermal in-ground conduit system as claimed in  claim 27  wherein a soil penetrating nose member is secured to said lower end section of said loop and in frictional contact with said leading edge of said interconnected side walls to provide ease of penetration of said soil penetrating head and protection of said lower end section of said loop, said soil penetrating nose member remaining embedded in the soil with said loop. 
     
     
         35 . A geothermal in-ground conduit system as claimed in  claim 34  wherein said soil penetrating nose member is provided with articulated anchor wings to anchor said lower end section and said loop in the soil after retraction of said soil penetrating head. 
     
     
         36 . A geothermal in-ground conduit system as claimed in  claim 2  wherein said soil penetrating head is a V-shaped soil penetrating head having a pointed leading end, said soil penetrating head being formed by a metal member of V-shaped transverse cross-section having a sharp forward leading edge for ease of penetration in the soil. 
     
     
         37 . A geothermal in-ground conduit system as claimed in  claim 36  wherein said coupling means is constituted by engageable formations formed with said soil penetrating head for removable engagement by a coupling secured to a free lower end of said force transmitting shaft. 
     
     
         38 . A soil penetrating head for use in a geothermal in-ground conduit, said soil penetrating head having a leading soil penetrating face formation, coupling means secured to said soil penetrating head rearwardly of said leading soil penetrating face formation and adapted to receive a force transmitting shaft, said leading soil penetrating face formation having a convex shaped forward sharp edge and opposed symmetrical shaped side walls tapering outwardly from an apex of said convex forward face, said lower end section of said loop extending in said soil penetrating head with said elongated side sections extending rearwardly of said soil penetrating head. 
     
     
         39 . A soil penetrating head as claimed in  claim 38  wherein said coupling means is a hollow tube section dimensioned to receive a free lower end of said force transmitting shaft therein. 
     
     
         40 . A soil penetrating head as claimed in  claim 38  wherein said coupling means is a tubular connector having engageable formations for detachable connection with further engageable formations at a free lower end of said force transmitting shaft. 
     
     
         41 . A soil penetrating head as claimed in  claim 40  wherein said engageable formations and further engageable formations are screw thread formations. 
     
     
         42 . A soil penetrating head as claimed in  claim 38  wherein said coupling means is a hollow coupling tube, said hollow coupling tube being connected in communication with said lower end section and said opposed side sections, said coupling tube having connection means for sealing engagement with a free lower end of said force transmitting shaft, said force transmitting shaft being a hollow shaft for convecting the heat exchange liquid therein and into said opposed side sections of said loop through said lower end section. 
     
     
         43 . A soil penetrating head as claimed in  claim 38  wherein said passage means is constituted by a curved conduit secured in said soil penetrating head, said curved conduit having opposed free ends accessible from said rear end, and means to immovably and sealingly connect opposed spaced-apart side sections of the at least one loop to a respective one of said opposed free ends of said curved conduit. 
     
     
         44 . A soil penetrating head as claimed in  claim 43  wherein there are two of said curved conduits disposed at substantially right angle to one another for connecting two of said loops of flexible tubing to said soil penetrating head. 
     
     
         45 . A soil penetrating head as claimed in  claim 38  wherein said coupling means is a hollow coupling tube, said hollow coupling tube being connected to each said opposed spaced-apart side section of said two loops and forming said lower end section of each said two of said loops, said coupling tube having connection means for sealing engagement with a free lower end of said force transmitting shaft, said force transmitting shaft being a hollow shaft for convecting the heat exchange liquid therein and into said opposed side sections of each said two of said loops, said hollow shaft having an internal transverse sectional area diameter equal to the totality of the internal transverse sectional area of said opposed side sections of said two of said loops. 
     
     
         46 . A soil penetrating head as claimed in  claim 38  wherein said soil penetrating head is formed from one of steel or high density plastics material having a forward cutting blade secured along said convex forward cutting edge. 
     
     
         47 . A method of constructing an in-ground conduit system to capture thermal energy stored in the ground, said method comprising:
 i) securing a lower end section of at least one loop of flexible tubing to a soil penetrating head, said loop having opposed spaced-apart elongated side sections, said soil penetrating head having a leading soil penetrating face formation;   ii) engaging said soil penetrating head to a lower end of a force transmitting shaft supported at a desired angle with respect to a soil surface adjacent a foundation of a building structure;   iii) applying a pushing force to said force transmitting shaft to displace said soil penetrating head in the soil with said opposed elongated side sections of said loop maintained spaced-apart; and   iv) said soil penetrating head pulling said loop and guiding same into the soil as said soil penetrating face forms passages for burial of at least a major portion of said loop.   
     
     
         48 . A method as claimed in  claim 47  wherein said step (i) comprises positioning said lower end section of said flexible tubing in a curved passage in said soil penetrating head from a rear end of said soil penetrating head to form said curved lower end section. 
     
     
         49 . A method as claimed in  claim 47  wherein said step (i) comprises sealingly securing an end of said opposed spaced-apart elongated side sections to opposed free ends of a curved conduit secured in said head and accessible from said rear end of said soil penetrating head. 
     
     
         50 . A method as claimed in  claim 47  wherein said step (i) comprises positioning said lower end section of said loop in a channel defined between side walls of said soil penetrating head and against an outer seating wall thereof. 
     
     
         51 . A method as claimed in  claim 47  wherein said step (ii) comprises positioning said lower end of said force transmitting shaft in a hollow tube section secured in said rear end of said soil penetrating head. 
     
     
         52 . A method as claimed in  claim 47  wherein said step (ii) comprises engaging an engageable formation at said lower end of said force transmitting shaft to an engageable formation of a tubular connector constituting said coupling means. 
     
     
         53 . A method as claimed in  claim 47  wherein after step (iii) there is provided the further step of securing at least one spacer device to said force transmitting shaft at one or more predetermined spacing along said shaft to maintain said spaced-apart elongated side sections of said flexible tubing in a spaced-apart orientation as it is drawn into the soil. 
     
     
         54 . A method as claimed in  claim 47  wherein said step (iii) is terminated when said soil penetrating head is arrested by a bedrock surface or a dense soil layer. 
     
     
         55 . A method as claimed in  claim 54  wherein there is further provided the steps of (a) retracting said force transmitting shaft after said soil penetrating head is arrested, (b) cutting said side sections of said flexible tubing above a surface of said soil for interconnection with further loops of adjacent flexible tubing disposed in the soil and to associated heat exchange equipment. 
     
     
         56 . A method as claimed in  claim 47  wherein after said step (iv) there is provided the step of retracting said force transmitting shaft from said soil penetrating head to maintain said soil penetrating head buried in the soil. 
     
     
         57 . A method as claimed in  claim 47  wherein after said step (iv) there is provided the step of retracting said force transmitting shaft and said soil penetrating head and maintaining said loop buried in the soil. 
     
     
         58 . A method as claimed in  claim 52  wherein said force transmitting shaft is a hollow shaft, said tubular connector being a hollow connector in flow communication with said curved lower end section of said loop of flexible tubing, said tubular connector having an inner transverse cross-section equal to the totality of the inner transverse cross-sectional area of both said elongated side sections of said flexible tubing, and wherein a heat exchange liquid is caused to flow into said hollow shaft and out through said elongated side sections of said flexible tubing. 
     
     
         59 . A method as claimed in  claim 55  wherein there are at least two or more of said loops of flexible tubing secured in said soil in side-by-side spaced relationship along substantially straight lines in a hole excavated in the soil and into which a concrete foundation is to be formed, said straight lines being positioned along a footing of a foundation to be later formed. 
     
     
         60 . A method as claimed in  claim 59  wherein said step (b) of cutting said side sections of said flexible tubing comprises exposing a predetermined length of said side sections above said surface of the soil to form tube open end sections, and wherein there is further provided the step of positioning an insulated protective sleeve about said tube open end sections and about which concrete is poured to form said footing, said open end sections being accessible inside concrete formation walls formed over said footing. 
     
     
         61 . A method as claimed in  claim 60  wherein there is further provided the step of sealingly securing tube connectors to said open end sections for coupling said two or more loops in series with one another to form a closed loop conduit circuit when connected to said associated heat exchange equipment. 
     
     
         62 . A method as claimed in  claim 47  wherein prior to step (i) there is provided the further steps of (a) forming a hole inside a foundation structure of a building through a foundation wall or floor, (b) securing an anchor plate to said foundation wall or floor at a desired position relative to said hole, (c) securing a pneumatic force applying device to said anchor plate, and (d) positioning said force transmission shaft in said pneumatic force applying device for engagement therewith and aligned with said hole at a desired angle to displace said soil penetrating head and said loop of flexible tubing into the soil adjacent said foundation structure through said hole. 
     
     
         63 . A method as claimed in  claim 62  wherein said step (d) comprises positioning a first section of said force transmission shaft in said pneumatic force applying device, actuating said pneumatic force applying device to displace said first section, securing a further section of said force transmission shaft to a rear end of said first section and further actuating said pneumatic force applying device, and repeating these steps until an operator person decides to discontinue the embedding of the loop of flexible tubing and its associated soil penetrating head.