Coaxial geothermal probe and method for making a coaxial geothermal probe

Abstract

A method for making coaxial geothermal probes that comprise a hollow outer pipe ( 2 ) and an inner pipe ( 5 ), wherein inserting the outer pipe ( 2 ) in the ground comprises: —driving into the ground using pressure, applying an axial thrust to it that is generated by means of a hydraulic actuator ( 30 ), a head element ( 13 ) that is tubular and closed at the bottom by a driving head ( 18 ) and equipped with a first thread ( 19 ) at the top; screwing a second thread ( 24 ) of an additional tubular element ( 14 ) to the first thread ( 19 ) of the head element ( 13 ), creating a fluidtight connection between the head element ( 13 ) and the additional element ( 14 ); further driving into the ground ( 11 ) using pressure the assembly constituted of the head element ( 13 ) and of the additional element ( 14 ), applying an axial thrust to them that is generated by means of a hydraulic actuator ( 30 ); and optionally performing once or more the steps of screwing the second thread ( 24 ) of a further additional element ( 14 ) to a free first thread ( 19 ) of an additional element ( 14 ) already driven into the ground ( 11 ) and connected to the head element ( 13 ), and further driving the whole assembly into the ground ( 11 ) using pressure.

1 . A method for making coaxial geothermal probes, comprising the operating steps of:
 inserting in the ground ( 11 ) a hollow outer pipe ( 2 ) comprising a first lower end ( 3 ) that is sealed in fluidtight way, and a first upper end ( 4 ) that is open;   inserting in the outer pipe ( 2 ) an inner pipe ( 5 ) coaxial with it, forming an annular chamber ( 6 ) coaxial with the inner pipe ( 5 ) and located between the inner pipe ( 5 ) and the outer pipe ( 2 ); the inner pipe ( 5 ) comprising a second lower end ( 7 ) that is positioned near the first lower end ( 3 ) and is in fluid communication with the annular chamber ( 6 ) and a second upper end ( 8 ) that is accessible near the first upper end ( 4 );   
       wherein the step of inserting the outer pipe ( 2 ) in the ground ( 11 ) comprises the operating steps of:
 preparing a head element ( 13 ) comprising a first straight tubular body ( 15 ) extending from a first end ( 16 ) to a second end ( 17 ), and a driving head ( 18 ) that seals the first end ( 16 ) in a liquidtight way, the second end ( 17 ) comprising a first thread ( 19 ); 
 starting with the driving head ( 18 ), driving the head element ( 13 ) into the ground ( 11 ) using pressure, applying an axial thrust to it that is generated by means of a hydraulic actuator ( 30 ); 
 preparing one or more additional elements ( 14 ) each comprising a second straight tubular body ( 21 ) extending from a third end ( 22 ) to a fourth end ( 23 ), the third end ( 22 ) and the fourth end ( 23 ) both being open, also the fourth end ( 23 ) comprising a first thread ( 19 ) and the third end ( 22 ) comprising a second thread ( 24 ) that can be screwed to the first thread ( 19 ) of the head element ( 13 ) or of a different additional element ( 14 ); 
 screwing the second thread ( 24 ) of an additional element ( 14 ) to the first thread ( 19 ) of the head element ( 13 ), creating a fluidtight connection between the head element ( 13 ) and the additional element ( 14 ); 
 further driving into the ground ( 11 ) using pressure the assembly constituted of the head element ( 13 ) and of the additional element ( 14 ), applying an axial thrust to them that is generated by means of a hydraulic actuator ( 30 ); 
 optionally performing once or more the steps of screwing the second thread ( 24 ) of a further additional element ( 14 ) to the free first thread ( 19 ) of an additional element ( 14 ) already driven into the ground ( 11 ) and connected to the head element ( 13 ), and further driving into the ground ( 11 ) using pressure the assembly constituted of the head element ( 13 ) and the additional elements ( 14 ) connected to it by screwing, applying an axial thrust to them that is generated by means of a hydraulic actuator ( 30 ). 
 
     
     
         2 . The method according to  claim 1 , wherein during the steps of driving using pressure, the head element ( 13 ) and any additional elements ( 14 ) are also made to rotate about their longitudinal axis. 
     
     
         3 . The method according to  claim 2 , wherein a head element ( 13 ) is used that is equipped with a driving head ( 18 ) externally comprising at least one set of blades or one helical thread ( 27 ). 
     
     
         4 . The method according to  claim 3 , wherein a head element ( 13 ) is used in which the set of blades or the helical thread ( 27 ) extend in such a way that their screwing into the ground ( 11 ) occurs with a direction that can cause screwing of each first thread ( 19 ) to a second thread ( 24 ) that may be coupled to it. 
     
     
         5 . The method according to  claim 3 , wherein the head element ( 13 ) and any additional elements ( 14 ) are also made to rotate about their longitudinal axis by means of the interaction between the set of blades or the helical thread ( 27 ) of the driving head ( 18 ) and the ground ( 11 ) under the action of the axial thrust acting on them. 
     
     
         6 . The method according to  claim 2 , wherein the head element ( 13 ) and any additional elements ( 14 ) are also actively made to rotate about their longitudinal axis by means of a specific actuator. 
     
     
         7 . The method according to  claim 1 , also comprising after all of the steps of driving using pressure, a step of filling any empty spaces present between the ground ( 11 ) and the first tubular body ( 15 ) and the one or more second tubular bodies. 
     
     
         8 . A coaxial geothermal probe, comprising:
 a hollow outer pipe ( 2 ) comprising a first lower end ( 3 ) that is sealed in fluidtight way and a first upper end ( 4 ) that is open; and   an inner pipe ( 5 ) coaxial with the outer pipe ( 2 ), an annular chamber ( 6 ), coaxial with the inner pipe ( 5 ), being present between the inner pipe ( 5 ) and the outer pipe ( 2 ); the inner pipe ( 5 ) comprising a second lower end ( 7 ) that is positioned near the first lower end ( 3 ) and is in fluid communication with the annular chamber ( 6 ), and a second upper end ( 8 ) that is accessible near the first upper end ( 4 );   
       wherein the outer pipe ( 2 ) comprises:
 a head element ( 13 ) in turn comprising a first straight tubular body ( 15 ) extending from a first end ( 16 ) to a second end ( 17 ), and a driving head ( 18 ) that seals the first end ( 16 ) in a liquidtight way, the second end ( 17 ) being open and comprising a first thread ( 19 ); 
 one or more additional elements ( 14 ) each comprising a second straight tubular body ( 21 ) extending from a third end ( 22 ) to a fourth end ( 23 ), the third end ( 22 ) and the fourth end ( 23 ) both being open, the fourth end ( 23 ) also comprising a first thread ( 19 ) and the third end ( 22 ) comprising a second thread ( 24 ) screwed to the first thread ( 19 ) of the head element ( 13 ) or of a different additional element ( 14 ); 
 
       and wherein the driving head ( 18 ) externally comprises at least one set of blades or one helical thread ( 27 ). 
     
     
         9 . (canceled) 
     
     
         10 . The geothermal probe according to  claim 8 , wherein the set of blades or the helical thread ( 27 ) extend in a helix with a direction of screwing opposite to that of the second threads ( 24 ) of the third ends ( 22 ). 
     
     
         11 . The geothermal probe according to  claim 8 , wherein the first thread ( 19 ) has a female shape and the second thread ( 24 ) has a male shape. 
     
     
         12 . (canceled) 
     
     
         13 . The geothermal probe according to  claim 10 , wherein the first thread ( 19 ) has a female shape and the second thread ( 24 ) has a male shape. 
     
     
         14 . The geothermal probe according to  claim 10 , wherein the first tubular body ( 15 ) and the second tubular body ( 21 ) have a circular cross-section and have the same maximum external radius, and wherein the driving head ( 18 ) has a maximum radial projection relative to a longitudinal axis of the first tubular body ( 15 ) that is greater than the maximum external radius. 
     
     
         15 . The method according to  claim 4 , wherein the head element ( 13 ) and any additional elements ( 14 ) are also made to rotate about their longitudinal axis by means of the interaction between the set of blades or the helical thread ( 27 ) of the driving head ( 18 ) and the ground ( 11 ) under the action of the axial thrust acting on them. 
     
     
         16 . The method according to  claim 3 , wherein the head element ( 13 ) and any additional elements ( 14 ) are also actively made to rotate about their longitudinal axis by means of a specific actuator. 
     
     
         17 . The method according to  claim 4 , wherein the head element ( 13 ) and any additional elements ( 14 ) are also actively made to rotate about their longitudinal axis by means of a specific actuator. 
     
     
         18 . The method according to  claim 2 , also comprising after all of the steps of driving using pressure, a step of filling any empty spaces present between the ground ( 11 ) and the first tubular body ( 15 ) and the one or more second tubular bodies. 
     
     
         19 . The method according to  claim 3 , also comprising after all of the steps of driving using pressure, a step of filling any empty spaces present between the ground ( 11 ) and the first tubular body ( 15 ) and the one or more second tubular bodies. 
     
     
         20 . The method according to  claim 5 , also comprising after all of the steps of driving using pressure, a step of filling any empty spaces present between the ground ( 11 ) and the first tubular body ( 15 ) and the one or more second tubular bodies. 
     
     
         21 . The method according to  claim 6 , also comprising after all of the steps of driving using pressure, a step of filling any empty spaces present between the ground ( 11 ) and the first tubular body ( 15 ) and the one or more second tubular bodies. 
     
     
         22 . The geothermal probe according to  claim 8 , wherein the first tubular body ( 15 ) and the second tubular body ( 21 ) have a circular cross-section and have the same maximum external radius, and wherein the driving head ( 18 ) has a maximum radial projection relative to a longitudinal axis of the first tubular body ( 15 ) that is greater than the maximum external radius.