Probe For Collecting Thermal Energy From The Ground For A Heat Pump, And A Collection Network Equipped With Such Probes

Abstract

The probe ( 10 ) comprises a circuit for circulating a heat-conveying fluid, between a fluid inlet ( 28 ) and a fluid outlet ( 34 ) connected to a heat pump. The circuit comprises at least two tubes ( 12, 14 ) extending in parallel, comprising a fluid admission tube ( 14 ) and a fluid return tube ( 12 ), the admission and return tubes being put into communication ( 24 ) with each other at their distal ends ( 18, 22 ). The tubes are made with a wall in common over their entire length, advantageously a wall that is isothermal. They may be engaged one inside the other ( 12, 14 ) or they may be adjoining. The assembly forms a single tubular element suitable for burying having a distal end that is free that can easily be introduced into a tunnel of small diameter that has been dug by a miniature boring machine. The return tube is provided with portions in relief ( 44 ) suitable for creating turbulence in the fluid flowing in said tube, whilst the inner wall of the fluid admission tube is smooth to encourage laminar flow of the fluid flowing in said tube.

1 . A collector probe for collecting heat energy from the ground for a heat pump, the probe ( 10 ) comprising a circuit for circulating a heat-conveying fluid, the circuit having a fluid inlet ( 28 ) and a fluid outlet ( 34 ) suitable for being connected to respective terminals ( 86 ,  90 ) of a heat pump ( 88 ), the circuit comprising at least two tubes ( 12 ,  14 ;  64 ,  66 ;  74 ,  76 ;  80 ,  82 ,  84 ) extending in parallel, with a fluid admission tube ( 14 ;  66 ;  76 ;  84 ) connected to the fluid inlet and a fluid return tube ( 12 ;  64 ;  74 ;  80 ,  82 ) connected to the fluid outlet, in which probe the fluid admission and return tubes are in communication with each other at their distal ends, are made with a wall in common over their entire length, and form a single tubular element for burying having a proximal end with the fluid inlet and outlet, and a distal end that is free,
 the probe being characterized in that the inside surface of the wall of the fluid return tube is provided with portions in relief ( 44 ) suitable for creating turbulence in the fluid flowing in said tube, and the inside surface of the wall of the fluid admission tube is a smooth surface suitable for encouraging laminar flow of the fluid flowing in said tube.   
   
   
       2 . The collector probe of  claim 1 , in which said common wall ( 36 ,  40 ,  46 ) is a wall with a thermally insulating core ( 46 ) and/or enclosing insulating cavities ( 48 ). 
   
   
       3 . The collector probe of  claim 1 , in which the fluid flow section of the return tube is greater than the fluid flow section of the admission tube. 
   
   
       4 . The collector probe of  claim 1 , in which the outside section of said single tubular element for burying is uniform over the entire length of said element. 
   
   
       5 . The collector probe of  claim 4 , in which the outside section of said single tubular element for burying is circular section. 
   
   
       6 . The collector probe of  claim 1 , in which the outside diameter (d) of said single tubular element for burying is less than 150 mm, preferably less than 100 mm, most preferably less than 50 mm. 
   
   
       7 . The collector probe of  claim 1 , in which the tubes are made of a flexible material suitable for conferring flexibility to said single tubular element for burying. 
   
   
       8 . The collector probe of  claim 1 , in which the distal end of said single tubular element for burying is provided externally with a fitted endpiece ( 20 ). 
   
   
       9 . The collector probe of  claim 1 , in which said fluid admission and return tubes are tubes ( 12 ,  14 ) engaged one inside the other, one of the tubes being an inner tube ( 14 ) open at its distal end ( 22 ), with its wall constituting said common wall, and the other of the tubes being an outer tube ( 12 ) containing the inner tube and closed at its distal end ( 18 ), the inside surface ( 38 ) of the inner tube ( 14 ) being smooth and the outside surface ( 42 ) of the same inner tube ( 14 ) being provided with said portions in relief ( 44 ). 
   
   
       10 . The collector probe of  claim 1 , in which said fluid admission and return tubes are adjoining tubes ( 64 ,  66 ;  74 ,  76 ;  80 ,  82 ,  84 ). 
   
   
       11 . The collector probe of  claim 10 , comprising a single fluid admission tube ( 66 ;  76 ) and a single fluid return tube ( 64 ;  74 ), and in which the section of the return tube is greater than the section of the admission tube. 
   
   
       12 . The collector probe of  claim 11 , comprising at least three tubes ( 80 ,  82 ,  84 ), with the number of fluid admission tubes ( 84 ) being less than the number of fluid return tubes ( 80 ,  82 ), and in which the total section of the return tube(s) is greater than the total section of the admission tube(s). 
   
   
       13 . The collector probe of  claim 1 , further comprising, over selected fractions of its length, reinforced insulation ( 98 ) of the fluid admission and/or fluid return tube. 
   
   
       14 . A collector network for collecting thermal energy from the ground for a heat pump, the network being characterized in that:
 it comprises a plurality of probes ( 10 ) according to any one of  claims 1  to  13 , the probes being buried in tunnels dug in the ground; and   it presents a three-dimensional configuration defined by an envelope volume ( 92 ) extending over a given area of ground and over a given burying depth.   
   
   
       15 . The collector network of  claim 14 , in which the probes ( 10 ) have reinforced insulation ( 98 ) of the fluid admission and/or return tubes over the portions thereof that extend between ground level and said envelope volume. 
   
   
       16 . The collector network of  claim 14 , in which said envelope volume extends to a depth lying in the range 0.5 m to 10 m below ground level. 
   
   
       17 . The collector network of  claim 14 , in which said probes are disposed with their terminal ends at their lowest points.