NL1038799C2 - GEO-THERMAL HEAT EXCHANGER SET-UP. - Google Patents

Description

Geo-thermal heat exchanger installation

BACKGROUND OF THE INVENTION

The invention relates to a method for introducing an elongate element into a bottom, in particular a tube assembly of a geothermal heat exchanger. The invention further relates to an arrangement with a geothermal heat exchanger and to a tube assembly, in particular for a geothermal heat exchanger.

It is known to place elongate elements, in particular tube assemblies of geothermal heat exchangers, in a soil by the following steps: - making a bore with the desired depth in the soil by driving a drill head provided with a drill head into the soil. hearing tube.

feeding a water / bentonite mixture during drilling, for discharging the bottom material.

the retrieval of the drill pipe.

inserting into the bore of the elongate element filled with the drilling fluid (mixture of the aforementioned water / bentonite mixture and bottom material) until the lower end thereof is at the desired depth.

Inserting a grout pipe from ground level, for filling the bore with a flowable, thermally conductive material, such as grout, forcing the drilling fluid out of the bore.

When the grout tube is introduced, whether or not together with the elongate element, the grout tube can engage in the borehole wall, as a result of which the grout tube is retained and / or as a result of which bottom material comes loose, also after passage of the distal end of the grout tube. On the one hand, this makes the input process more difficult and, on the other hand, bottom material collects in the lower end of the bore. The latter can result in the grout tube getting stuck at the distal end and difficult to retrieve.

In order to prevent these problems, a diameter is taken for the drill pipe such that the elongate element and grout pipe can be introduced more easily. For example, with a pipe assembly for 63 mm geothermal heat exchanger and a 40 mm diameter grout pipe, a 140 mm drill pipe is used. Filling the bore therefore requires a lot of grout in relation to the diameter of the pipe assembly. This also means that the distance from the hole wall to the pipe assembly is quite large. In addition, a borehole with a larger diameter provides more soil material to be removed and removed. Furthermore, the drilling costs and the power to be used depend on the diameter

SUMMARY OF THE INVENTION

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It is an object of the invention to provide a method of the type mentioned in the preamble with which a fast and / or reliable filling of the drill pipe with flowable, thermally conductive material is possible.

It is an object of the invention to provide a method of the type mentioned in the preamble with which an arrangement of a geothermal heat exchanger can be obtained with a high efficiency.

An object of the invention is to provide a method of the type mentioned in the preamble which can be cost-effective.

An object of the invention is to provide an arrangement of the type mentioned in the preamble 20 with a geothermal heat exchanger with which a high efficiency can be achieved.

An object of the invention is to provide a pipe assembly with which a fast and / or reliable filling of the drill pipe with flowable, thermally conductive material is possible.

An object of the invention is to provide a pipe assembly with supply line that can be introduced into a borehole without many problems.

From one aspect the invention provides a method for introducing an elongate element from a bottom surface into a bottom, in particular a tube assembly of a geothermal heat exchanger, wherein a drill pipe with a drill head at the distal end is driven into the bottom at a desired depth, wherein the elongate element is introduced from the bottom surface into the realized bore until it reaches the desired depth with the distal end, wherein with or following the elongate element a liquid pipe which is deformable in section in a condition with a small section , in particular a flat condition, is introduced into the bore, and wherein, in particular after the distal end of the liquid line is brought into the bore at the desired depth, thermally conductive material such as grout or the like, is forced through the fluid conduit while enlarging the diameter of the fluid conduit and out of it distal end of the fluid conduit for filling the bore with the thermally conductive, flowable material.

By introducing the liquid line into the bore in the reduced-diameter state, in particular a flat state, the joint cross-section of the elongate element and the liquid line can remain smaller, so that the diameter of the borehole can also remain smaller (in the above-mentioned situation, for example, 10 cm), without increasing the risk of loosening borehole material or making insertion more difficult. This saves on the amount of soil material to be removed, the amount of filling material and on drilling costs.

In a simple embodiment, the liquid line is pre-attached to the elongate element and is introduced into the bore together with it. The elongated element then functions as a carrier for the liquid line, so that an additional step of introducing the liquid line is avoided.

The required diameter of the bore or borehole is limited if the liquid line is placed flat around a part of the outer surface of the elongate element, parallel to it. The flat liquid line then follows the wall shape of the elongate element and will then in fact be able to form no more than a small thickening thereof.

If during the introduction of the elongate element the bore 25 is filled with drilling fluid and the thermally conductive material has a higher specific gravity than the drilling fluid, the drilling fluid with the introduction of the thermally conductive material into the bore will be forced out of the bore . By introducing the flowable, thermally conductive material from below into the bore, the drilling fluid can be gradually brought out of the bore through simple upward displacement. Mixing which otherwise occurs between downward flowing thermally conductive material and upwardly displaced drilling fluid is largely prevented.

In one embodiment, when the elongate element is introduced into the bore, the fluid line is connected to the elongate element by means of a collapsible connection, preferably near the distal end of the fluid line and / or near the distal end of the elongate element. As a result of the collapsible connection, the liquid line is carried into the drill pipe during the introduction of the elongate element, but the connection can then be broken. An advantageous consequence thereof is that the liquid line can be withdrawn during the filling of the bore with the thermally conductive, flowable material. As a result, the liquid line with the distal end can follow the top of the thermally conductive filling material, whereby the filling process is promoted. The deformability of the liquid line promotes retraction.

Alternatively, the distal end of the fluid conduit may be maintained near the distal end of the elongate member during delivery of the thermally conductive flowable material.

In one embodiment, the bore tube can be withdrawn from the bore during the filling of the bore with the thermally conductive, flowable material.

Alternatively, the drill pipe can be withdrawn from the bore already prior to filling the bore with the thermally conductive, flowable material, as has already been mentioned above.

In one embodiment, the liquid line is located eccentrically on the outside of the elongate element. Upon obtaining the circular cross-section, the liquid line can force the elongate element to an eccentric location in the bore, in particular press it into abutment with the wall of the bore. As a result, under certain circumstances the thermal transfer there between heat exchanger and bottom material can be promoted.

For geothermal applications, the elongate element may comprise a coaxial tube assembly, with an inward flow passage and a concentric annular outflow flow passage, the distal end comprising a cap in which the flow passage is connected to the flow passage.

From a further aspect the invention provides a method for introducing an elongate element from a bottom surface into a bottom, in particular a tube assembly of a geothermal heat exchanger, wherein a drill pipe with a drill head at the distal end is driven into the bottom to a desired depth, wherein, whether or not after withdrawing at least the drill pipe from the bottom, the elongated element is introduced from the bottom surface into the realized bore, wherein, after inserting the bore into the bore at the desired depth distal end of the elongated element, the elongated element is forced into an eccentric position relative to the bore, preferably pressed into abutment with the wall of the bore and the bore is filled with thermally conductive flowable material, such as grout or the like.

In this case, a liquid line can be introduced along with or following the elongated element into the bore, and, after the distal end of the elongated element is introduced into the bore at the desired depth, the thermally conductive flowable material is passed through the liquid line. lined which thereby expands while pushing the elongate element toward the bore wall. The flowable material then continues to be supplied to emerge from the distal end of the fluid conduit for filling the bore with the thermally conductive, flowable material. The aforementioned aspects of the liquid line according to the invention can also be applicable here.

If the bore does not extend vertically, it may be advantageous to press the elongate element against the upper wall portion of the bore, because then the material of the borehole wall is additionally retained therein.

From a further aspect, the invention provides an arrangement of a tube assembly for a geothermal heat exchanger in a bore made for this purpose in a bottom, wherein a thermally conductive mass is present in the space between the tube assembly and the bore wall, the tube assembly over at least substantially the entire length lies eccentrically in the bore, preferably abutting on one side against the bore wall. In a first embodiment, the bore wall is defined by a lost hearing tube. In a second embodiment, the bore wall is defined by the bottom material. As discussed above, the elongate member may comprise a coaxial tube assembly, having an inward flow passage and an annular outflow flow concentric therewith, the distal end comprising a cap in which the flow of flow is connected to the flow of flow.

From a further aspect the invention provides a coaxial tube assembly for a geothermal heat exchanger, with an outer tube and an inner tube, the inner tube defining an inner flow passage and the inner tube and outer tube defining an annular outer flow passage concentric therewith, the distal end of the tube assembly forming a cap wherein the inner flow passage is connected to the outer flow passage, wherein an additional supply line for fluid is arranged on the outer tube, preferably on one side. The supply line preferably has a flat state and is expandable to a round state under internal pressure. The supply line can be connected to the outer tube by means of a collapsible connection, preferably near the distal end of the supply line and / or near the distal end of the outer tube.

From a further aspect the invention provides a method for introducing an elongate element from a bottom surface into a bottom, in particular a tube assembly of a geothermal heat exchanger, wherein a hearing tube with a drill head at the distal end is driven into the bottom to a desired depth, wherein, whether or not after withdrawing at least the hearing tube from the bottom, the elongated element is introduced from the bottom surface into the realized bore, wherein with or following the elongated element a liquid line is entrained in the bore and wherein, after introducing the distal end of the elongate element into the bore 15 at a desired depth, thermally conductive flowable material, such as grout or the like, is passed through the fluid conduit and exits the distal end of the fluid conduit for filling the bore with the thermally conductive, flowable material.

The aspects and measures described in this description and claims of application 20 and / or shown in the drawings of this application can, where possible, also be applied separately from each other. These individual aspects can be the subject of split-off patent applications that are aimed at this. This applies in particular to the measures and aspects that are described per se in the subclaims.

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BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be elucidated on the basis of an exemplary embodiment shown in the accompanying drawings. Shown are: Figures 1 to 4 a few steps in an exemplary embodiment of a method according to the invention;

Figures 1A-4A show cross-sections of Figures 1-4;

Figure 5 shows a schematic representation of an exemplary embodiment of an arrangement according to the invention; and Figure 6 shows a schematic representation of a tube assembly according to the invention.

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DETAILED DESCRIPTION OF THE DRAWINGS

Figures 1-4 show a bottom 100 with an upper surface or ground level 101. A hole 102 was previously made in the bottom 100 with a hearing tube 5 with a drilling tip, after which the hearing tube was retrieved. The bore 102 is filled with drilling fluid 104, a mixture of soil material and bentonite / water mixture with a specific gravity of slightly more than 1. The bore 102 has a wall 103.

In figure 1 a tube assembly 1, see also figure 6, in which the tube assembly 1 is schematically shown on roll 40, is fed in the direction B into the bore 102. This can be done, for example, by providing a weight at the lower end thereof 8 or by exerting a pushing force on the circumference of the tube assembly 1 or by driving a coil on which the tube assembly 1 is supplied. The tube assembly 1 is intended as a geothermal heat exchanger and comprises a coaxial tube set, namely an outer tube 2 of thermally conductive plastic, for example an HDPE, with a diameter of 63 mm, and an inner tube 3 of plastic foam material with closed cells, for example of a polyethylene . The inner tube 3 has two molded ribs 6, inter alia for centering the inner tube 3 in the outer tube 2. Thus, in the tube assembly 1, an annular flow passage 4 and a flow passage 5 located therein are formed. A heat exchanger fluid, in particular liquid, more in particular water, can flow downwards through one passage and upwards through the other, with reversal taking place in the end cap 7 at the distal end of the tube assembly.

A hose 10 with a flexible wall 11 (for example of polyethylene) is arranged against the outside of the outer tube 2. The hose 10 is open at the distal end 10a, but in its vicinity by means of a collapsible connection, shown here schematically with a breaking rope 12, 30 fixed on the outer tube 2. An alternative is, for example, a tape, in particular a tape which is tearable across its length.

In Figure 2, the hose 10 is filled from above with a flowable, thermally conductive material 20, for example grout with a heat conduction coefficient of more than 0.7, preferably more than 2.5. The material 20 causes the hose 10 to expand. The strength of the collapsed connection 12 is chosen such that after filling of the hose 10 the connection 12 is still intact. By expanding the hose 10, arrows C in Figure 2A, it comes against 8 the bore wall 103 and the tube assembly 1 is pressed in the direction D against the bore wall 103.

By increasing the filling pressure of the hose 10 with a pulse, it is ensured that the connection 12 fails. Then the distal end 10a 5 of the hose 10 is free and can open. The flowable material 20 flows, in the direction of E (Fig. 3), from the distal hose end 10a and starts to fill the bore 102. Because the material 20 is much heavier (specific weight of 1.5 or more) than the drilling fluid 104, the drilling fluid 104 is forced upwardly and the direction of the material 20 rises (towards F). The drilling fluid 104 leaves the surface 101 the bore 102, direction G. When it is suspected that the mirror of the material 20 has reached the distal tube end 10a, the tube 10 is pulled up (direction H, Fig. 4), in register with the rise of the mirror of material 20. The bore 102 thus becomes more and more filled with the material 20 which forces the drilling fluid 204 out of the bore 201. The deformable section of the hose 10 promotes the recovery of the hose,

Finally, the entire bore 102 is filled with the thermally conductive material 20, the tube assembly 1 being held eccentrically in the bore, see Figure 5, in which the center line S of bore 102 and center line T of tube assembly 1 are indicated. The bore 102 is closed at the top with a cap 30. The pipe assembly 1 is provided at the top with a splitting cap 31, with connection spout 31a for a supply line of heat exchanger fluid to the inner tube 3 and a connection spout 31b for a discharge line of the heat exchanger fluid originating from ring space 5.

The above description is included to illustrate the operation of preferred embodiments of the invention, and not to limit the scope of the invention. Starting from the above explanation, many variations will be apparent to those skilled in the art that fall within the spirit and scope of the present invention.

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Claims (30)

Method for introducing an elongate element from a bottom surface into a bottom, in particular a tube assembly of a geothermal heat exchanger, wherein a hearing tube with a drill head at the distal end is driven into the bottom to a desired depth, the elongated element is introduced from the bottom surface into the realized bore until it reaches the desired depth with the distal end, wherein with or following the elongated element a cross-sectional fluid line in a small-sectioned, especially flat-shaped condition, is introduced into the bore, and, particularly after the distal end of the fluid conduit is introduced into the bore at the desired depth, thermally conductive material such as grout or the like is forced through the fluid conduit under magnification of the cross-section of the fluid line and from the distal end of the fluid line occurs filling the bore with the thermally conductive, flowable material. The method of claim 1, wherein the fluid conduit is pre-attached to the elongate member and is introduced therewith into the bore. 3. Method as claimed in claim 2, wherein the liquid conduit is placed flat around a part of the outer surface of the elongate element, obtains a circular cross-section parallel thereto and through the flowable material. 4. Method as claimed in claim 2 or 3, wherein the liquid conduit is connected to the elongated element by means of a collapsible connection when the elongate element is introduced into the bore, preferably near the distal end of the liquid conduit and / or near the distal end of the elongated element. 5. Method as claimed in any of the foregoing claims, wherein the liquid line is withdrawn during filling of the bore. 6. Method as claimed in any of the foregoing claims, wherein the distal end of the liquid line is held near the distal end of the elongate element during the delivery of the thermally conductive, flowable material. 7. Method as claimed in any of the foregoing claims, wherein during the introduction of the elongate element the bore is filled with drilling fluid, wherein the thermally conductive material has a higher specific gravity than the drilling fluid and the drilling fluid with supplying the thermal into the bore -conducting material is forced out of the bore at the top. A method according to any one of the preceding claims, wherein the hearing tube is withdrawn from the bore during the filling of the bore with the thermally conductive, flowable material. io A method according to any one of the preceding claims, wherein the hearing tube is withdrawn from the bore prior to filling the bore with the thermally conductive, flowable material. 10. Method as claimed in any of the foregoing claims, wherein the liquid conduit is located eccentrically, on the outside of the elongate element 15. A method according to any one of the preceding claims, wherein in obtaining the enlarged cross-section, the liquid line forces the elongated element to an eccentric location in the bore. 12. A method according to claim 11, wherein the elongated 20 element is pressed into abutment with the wall of the bore. 13. Method as claimed in any of the foregoing claims, wherein the elongated element comprises a coaxial tube assembly, with an inner flow passage and a ring-shaped outer flow passage concentric therewith, wherein the distal end comprises a cap in which the inner flow passage is connected to the outflow passage. 14. Coaxial tube assembly for a geothermal heat exchanger, with an outer tube and an inner tube, the inner tube defining an inner flow passage and the inner tube and outer tube defining an annular outer flow passage concentric therewith, the distal end of the tube assembly comprising a cap in which the inner flow passage is connected with the outer flow passage, wherein on the outer tube, preferably one-sided, an additional supply line for fluid is arranged, which is deformable in cross-section. 15. Pipe assembly according to claim 14, wherein the supply line has a flat state and can be expanded to a round state under internal pressure. Tube assembly according to claim 15, wherein the supply line is connected to the outer tube by means of a collapsible connection, preferably near the distal end of the supply line and / or near the distal end of the outer tube. 17. Pipe assembly according to claim 14,15 or 16, arranged on a supply roll. 18. Method for introducing an elongate element from a bottom surface into a bottom, in particular a tube assembly of a geothermal heat exchanger, wherein a hearing tube with a drill head at the distal end is driven into the bottom to a desired depth, , whether or not after withdrawing at least the hearing tube from the bottom, the elongated element is introduced from the bottom surface into the realized bore, a liquid line being introduced along with the elongated element into the bore, and wherein, after the desired depth insertion into the bore of the distal end of the elongate element thermally conductive flowable material, such as grout or the like, is passed through the fluid conduit and emerges from the distal end of the fluid conduit for the thermally conductive fluidized material filling the bore. 19. Method for introducing an elongate element from a bottom surface into a bottom, in particular a tube assembly of a geothermal heat exchanger, wherein a hearing tube with a drill head at the distal end is driven into the bottom to a desired depth, wherein whether or not after retracting at least the hearing tube from the bottom, the elongated element is introduced from the bottom surface into the realized bore, wherein, after inserting the distal end of the elongated element into the bore at the desired depth, the elongate element is urged to an eccentric location with respect to the bore, preferably until it is pressed into abutment with the wall of the bore and the bore is filled with thermally conductive flowable material such as grout or the like. A method according to claim 19, wherein with or following the elongate element, a fluid line which is deformable in section is co-fed into the bore, and wherein, after inserting the distal end of the elongate element into the bore at the desired depth, thermally conductive flowable material is passed through the liquid conduit, which thereby expands while pressing the elongate element toward the bore wall. The method of claim 20, wherein the flowable material exits the distal end of the fluid conduit to fill the bore with the thermally conductive, flowable material. A method according to claim 20 or 21, comprising the steps 5 according to one or more of claims 1 to 9. 23. Arrangement of a tube assembly for a geothermal heat exchanger in a bore made therefor in a bottom, wherein a thermally conductive mass is present in the space between the tube assembly and the bore wall, the tube assembly eccentrically extending over at least substantially the entire length in the bore lies, preferably on one side, against the bore wall. The arrangement of claim 23, wherein the bore wall is defined by a lost hearing tube. 25. Arrangement according to claim 23, wherein the bore wall is determined by the bottom material. 26. Arrangement as claimed in any of the claims 23-25, wherein the elongate element comprises a coaxial tube assembly, with an inflow flow passage and an annular outflow flow passage concentric therewith, wherein the distal end comprises a cap in which the inflow flow passage is connected to the outflow flow passage. The arrangement of claim 26, wherein the diameter of the tube assembly is slightly more than 6 cm and the diameter of the bore is about 10 cm. 28. Pipe assembly provided with one or more of the characterizing measures described in the attached description and / or shown in the attached drawings. 29. Arrangement provided with one or more of the characterizing measures described in the attached description and / or shown in the attached drawings. 30. Method provided with one or more of the characterizing measures described in the attached description and / or shown in the attached drawings. -o-o-o-o-o-o-o-o- 1 0 3 8 799