FLEXIBLE SEALING TUBE AND METHOD FOR PRODUCING THE SAME

Abstract

A flexible sealing tube is described that is adapted to be installed in and extend along a bore in the ground for use in a system for exchanging of energy with the ground. The flexible sealing tube has a first tube end to be installed at an inner part of said bore, and the flexible sealing tube is closed in the first tube end. The flexible sealing tube also has a first channel and a second channel extending in a longitudinal direction (L) of the flexible sealing tube, the first and second channels being in fluid connection with each other. The first and second channels are formed by the flexible sealing tube.

Claims

1. A flexible sealing tube (2) adapted to be installed in and extend along a bore in a ground (3) for use in a system for exchanging of energy (1) with the ground (3), said flexible sealing tube (2) comprising a first tube end (4) to be installed at an inner part of said bore, said flexible sealing tube (2) being closed in said first tube end (4), said flexible sealing tube (2) further comprising a first channel (6) and a second channel (7) extending in a longitudinal direction (L) of said flexible sealing tube (2), said first and second channels (6, 7) being in fluid connection with each other, wherein said first and second channels (6, 7) are formed by said flexible sealing tube (2).

2. The flexible sealing tube (2) according to claim 1, wherein said first and second channels (6, 7) each comprises a first end portion (6a, 7a), said first end portions (6a, 7a) being located adjacent to said first tube end (4), and wherein said first and second channels (6, 7) are in fluid connection with each other in said first end portions (6a, 7a).

3. The flexible sealing tube (2) according to claim 1 or 2, wherein said flexible sealing tube (2) comprises a second tube end (5).

4. The flexible sealing tube (2) according to claim 3, wherein said first and second channels (6, 7) each comprises a second end portion (6b, 7b), said second end portions (6b, 7b) being located adjacent to said second tube end (5) and said second end portions (6b, 7b) of said first and second channels (6, 7) are each adapted to be operatively connected to a heat exchanging device (8).

5. The flexible sealing tube (2) according to claim 4, wherein said second tube end (5) is closed and said first and second channels (6, 7) are operatively connected to said heat exchanging device (8) via a respective first and second inlet/outlet opening (9, 10) provided in said flexible sealing tube (2).

6. The flexible sealing tube (2) according to claim 5, wherein at least one of said inlet/outlet openings (9, 10) is provided with a valve means (11, 12).

7. The flexible sealing tube (2) according to any one of the preceding claims, wherein said flexible sealing tube (2) comprises a longitudinally extending first joint (13), said first and second channels (6, 7) being provided on opposite sides of said longitudinally extending first joint (13).

8. The flexible sealing tube (2) according to claim 7, wherein said longitudinally extending first joint (13) is formed by a welding, gluing or the like.

9. The flexible sealing tube (2) according to any one of the preceding claims, wherein said fluid communication between said first and second channels (6, 7) is formed by an opening (14) between said first and second channel (6, 7).

10. The flexible sealing tube (2) according to claim 9, wherein said opening (14) between said first and second channel (6,7) is located in an area in which said first and second channels (6,7) are joined together by a second joint (15) and said opening (14) is completely surrounded by said second joint (15) .

11. The flexible sealing tube (2) according to any one of the preceding claims, wherein said flexible sealing tube (2) comprises a thermoplastic material, such as for example polyamide or polyester.

12. The flexible sealing tube (2) according to any one of the preceding claims, wherein said flexible sealing tube (2) comprises a textile material.

13. A method for manufacturing a flexible sealing tube (2) adapted to be installed in and extend along a bore in the ground (3) for use in a system for exchanging of energy (1) with the ground (3), comprising the step of; a) providing a tube-shaped flexible sealing material (2), said tube-shaped flexible material (2) having a first end (4) and a second end (5); b) forming a longitudinally extending first joint (13) thus forming a flexible sealing tube (2) comprising a first and a second longitudinally extending channel (6, 7) separated by said longitudinally extending first joint (13), said first and second longitudinally extending channels (6, 7) each comprising a first end portion (6a, 7a) and a second end portion (6b, 7b), said first channel (6) having a first channel wall (16) and said second channel (7) having a second channel wall (17), and; c) fluidly connecting said first and second channels (6, 7) by providing an opening (14) between said channels (6, 7).

14. The method according to claim 13, wherein step c) comprises the steps of; c1) joining said first and second channel walls (16, 17) with a second joint (15) over a joined area, and; c2) forming an opening (14) within said joint area such that said opening (14) is completely surrounded by said second joint (15).

15. The method according to claim 14, wherein said joined area formed by said second joint (15) between said first and second channel walls (16, 17) is formed by welding.

16. The method according to claim 15, wherein step c1), said joined welded area is formed by inserting welding means (19), such as electrodes, in said first and second channel (6, 7) and welding together said first and second channel walls (16, 17) to form said joined welded area.

17. The method according to any one of claims 13-16, wherein step a) said tube-shaped flexible sealing material (2) is achieved by folding a flexible sealing material to form a tube.

18. The method according to any one of claims 13-17, wherein said method further comprises a step d) of joining said first tube end (4) with a third joint (18).

19. The method according to claim 18, wherein step d) comprises forming said first tube end (4) to provide said first tube end (4) with a tapering shape.

20. A flexible sealing tube (2) adapted to be installed in and extend along a bore in a ground (3) for use in a system for exchanging of energy (1) with the ground (3), wherein said flexible sealing tube (2) is manufactured according to any one of claims 13-19.

21. A flexible sealing tube (2) according to claim 20, wherein said flexible sealing tube (2) is a flexible sealing tube (2) according to any one of claims 1-12.

22. Use of a flexible sealing tube (2) according to any one of claim 1-12 or 20-21 in a system for exchanging of energy (1) with a ground (3), wherein said flexible sealing tube (2) is installed in and extending along a bore in the ground (3).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0047] FIG. 1a illustrates a cross-sectional view of a flexible sealing tube according to the present disclosure installed in an energy well;

[0048] FIG. 1b illustrates a cross-sectional view of the flexible sealing tube shown in FIG. 1a

[0049] FIG. 2 illustrates a perspective view of the first end portions of the first and second channels of a flexible sealing tube according to the present disclosure;

[0050] FIG. 3 illustrates a cross-sectional view of the flexible sealing tube according to the present disclosure;

[0051] FIG. 4 illustrates a cutaway view of the flexible sealing tube according to the present disclosure;

[0052] FIG. 5a-k shows schematically a process for producing the flexible sealing tube in FIGS. 1-4.

DETAILED DESCRIPTION

[0053] It is to be understood that the drawings are schematic and that individual components, such as layers of materials, joints and openings are not necessarily drawn to scale. The flexible sealing tube shown in the figures are provided as examples only and should not be considered limiting to the invention. Accordingly, the scope of invention is determined solely by the scope of the appended claims.

[0054] FIG. 1a illustrates a system for exchanging of energy 1 with the ground 3. The system 1 comprises a flexible sealing tube 2 installed in and extending along a bore in a ground 3. The bore is a generally vertical bore in the ground. The bore is used as energy well for extracting, for example, heat for heating a house (not shown) or for storing heat in the ground 3. Such bores are most often vertical, but may however also be an inclined bore or a horizontally extending bore. At the upper part of the bore 2 the ground 3 is constituted of soil instead of rock. The rock may also penetrate the soil up to the ground surface, but it may also be present hundreds of meters down from the ground surface. Under normal conditions the rock may be found somewhere between a few up to ten to twenty meters underneath the ground level. The flexible sealing tube according to the present disclosure may be used under all of these conditions.

[0055] The flexible sealing tube 2, when installed in the bore in the ground 3 and filled with a liquid, will seal against the perimeter of the bore such that the flexible sealing tube 2 seals of different levels along the bore and the risk for contamination between different levels along the bore is reduced.

[0056] The flexible sealing tube 2 comprises a closed first tube end 4 installed at the inner part of the bore and a second tube end 5 close to the mouth of the bore at the ground level. Between the ground level and the upper surface of the bore a casing 28, normally a concrete casing, may be installed to shield the bore from the earth layers. The vertical upper end of the casing may be shielded with a casing cover or seal.

[0057] The flexible sealing tube 2 furthermore forms a first channel 6 and a second channel 7 extending in a longitudinal direction (L) of the flexible sealing tube 2. The first and second channels 6, 7 are in fluid connection with each other via an opening 14 formed between the first and second channels 6, 7. The first and second channel 6, 7 each comprises a respective first end portion 6a, 7a located adjacent to the first tube end 4. The first and second channels 6, 7 are in fluid connection with each other in their respective first end portions 6a, 7a.

[0058] The first and second channel 6, 7 each comprises a respective second end portion 6b, 7b located adjacent to the second tube end 5. The second end 5 is connected to piping's leading into a heat exchanging device 8.

[0059] The second end portions 6b, 7b of the first and second channels 6, 7 are each adapted to be operatively connected to a heat exchanging device 8, such as a heat pump system. The first channel 6 is connected to the heat exchanging device 8 via a first inlet/outlet opening 9 and the second channel 7 is connected to the heat exchanging device 8 via a second inlet/outlet opening 10. Each of the inlet/outlet openings 9,10 are provided in the wall of the flexible sealing tube 2. The first and the second inlet/outlet openings 9,10 are provided with a respective valve 11, 12 for controlling the flow and pressure of the liquid in the system for exchanging of energy 1. The first and second inlet/outlet openings 9,10 are connected to the heat exchanging device 8, such as a heat pump, via steel or plastic pipes 22,23.

[0060] In order to extract energy from the energy well, the heat pump circulates the liquid in the system 1 and the pipe 22 supplies liquid into the first channel 6. The over pressure produced by the heat pump transports the liquid from the first channel 6 and into the second channel 7, via the opening 14 positioned close to the first tube end 4 of the flexible sealing tube 2. To maximize the energy exchange from the bore, the opening 14 should be positioned as close to the first tube end 4 as possible. The second channel 7 returns the liquid to the heat pump system 8 where the heat energy absorbed by the liquid is extracted and may be transferred to a heating system of a house. The liquid utilized in the system 1 conventionally comprises water and an anti-freezing agent, however it is also possible to use only water or other liquids. The pressure exerted by the liquid in the flexible sealing tube 2 will press the outer walls of the flexible sealing tube 2 against the walls of the bore which effectively closes off water surrounding the flexible sealing tube 2 within the bore from penetrating from one vertical level within the bore to another to another vertical level within the bore.

[0061] The system for extracting energy 1 from the ground 3 may also be driven in the reverse direction, such as if the system is to be utilized for storing energy from the ground 3 or to cool the liquid in a cooling system for buildings or other applications.

[0062] The flexible sealing tube 2 is preferably made of a thermoplastic textile material, such as for example a woven material made of polyamide or polyester. The material should be substantially water impermeable and sealable, preferable weldable. Other sealing methods may be used if working adequately with the material of the flexible sealing tube 2. The woven material may be made from synthetic thermoplastic fiber yarns, such as for example from polyamide or polyester. The woven material may be coated with a coating material to provide a liquid impermeable material, the coating may be a silicon or polyurethane coating. The material may for example have a weight, including coating, of from 500 g/m.sup.2 to 1250 g/m.sup.2.

[0063] The flexible sealing tube 2 is at its first end 4 sealed with a third joint 18 (shown in FIG. 1b) so that no water from the ground penetrates the flexible sealing tube 2. The third joint 18 is thus a water-impermeable joint. The joints are preferably provided by welding a continuous weld seam. The flexible sealing tube 2 is provided with a hole 20 in the end portion for attachment of a load 21 to facilitate lowering of the flexible sealing tube 2 into the bore in the ground 3. The channels 6 and 7 are, in the second end 5, connected to a top head being the connecting device between the channels 6,7 and piping 22,23.

[0064] The length of the flexible sealing tube 2 is adapted to extend substantially all the way up the mouth of the bore at the ground level. One reason why it may be suitable for the flexible sealing tube 2 to extend slightly beneath the level of the mouth of the bore is that it prevents undesirable manipulation or damaging of the flexible sealing tube 2. In such cases, a suitable level of the second tube end 5 may be adjacent to the transition between the frost level and the frost-free level, which in Sweden corresponds to about 1-2 meters below ground level. The part of the bore situated above the second tube end 5, but beneath the mouth of the bore is sealed and may for example be covered with earth. It should be noted that normally all arrangements and fittings for a heat exchange system is concealed underground 3 to prohibit manipulation or weather impacts.

[0065] The flexible sealing tube 2 may typically have a length of 100-200 meters, to extend substantially all the way down to the bottom of the bore. The length of the flexible sealing tube 2 may be adjusted to fit the intended bore, the flexible sealing tube 2 may thus be both shorter and longer depending on the requirements of the specific energy well. The diameter of the flexible sealing tube may be from 10 to 25 cm, which should correspond to the diameter of the bore in which the flexible sealing should be installed.

[0066] FIG. 1b is a cross-sectional view of the flexible sealing tube 2 shown in FIG. 1a. The fluid connection between the first and the second channels 6, 7 is provided by the openings in the first and second channel walls 16,17 which are folded against each other such that the openings located in each of the first and second channel walls 16,17 forms the fluidly connecting opening 14. The first and second channel walls 16,17 are joined with a second joint 15 over a joined area and the opening 14 is punched out within the joined area in each of the first and second channel wall 16,17 such that the opening 14 is completely surrounded by the second joint 15. This is also illustrated in FIG. 2, which is a perspective view of the flexible sealing tube 2 in the first end portion part. The joint 15 is a water-impermeable joint forming a water-impermeable seal around the opening 14.

[0067] FIG. 3 is a cross-sectional view taken along lines III-III in FIG. 2 and illustrates the flexible sealing tube 2 with a longitudinally extending first joint 13 and the first and second channels 6, 7 provided on opposite sides of the longitudinally extending first joint 13. As may be seen in FIG. 3, the flexible sealing tube 2 is folded over the longitudinally extending first joint 13 with the first and the second channel walls 16, 17 in contact with each other. The longitudinally extending first joint 13 may formed by sealing through for instance gluing or welding, for instance with high frequency weld to form a continuous joint.

[0068] The joints provided to the flexible sealing tube 2 is preferable performed by means of the same sealing method, preferably by the same welding method. The width of each of the joints is preferably within the range of from 10 to 75 mm. The width of the joints 13 and/or 15 may be around from 15 to 35 mm, however the width may from around from around 45 to 75 mm to strengthen critical parts.

[0069] According to the above disclosure the flexible sealing tube 2 may consequently be described in general terms as being adapted to be installed in and extend along a bore in a ground 3 for use in a system for exchanging of energy 1 with the ground 3. The flexible sealing tube 2 comprises a first tube end 4 to be installed at an inner part of the bore. The flexible sealing tube 2 is closed in the first tube end 4, and comprises further a first channel 6 and a second channel 7 extending in a longitudinal direction L of the flexible sealing tube 2. The first and second channels 6, 7 are in fluid connection with each other, and are formed by the flexible sealing tube 2.

[0070] FIG. 4 is a cutaway view of the first end portion 6a of the flexible sealing tube 2, showing the first channel 6 and the opening 14 located between the first and second channel walls 16,17 and the joint 15 surrounding the opening 14. The width of the joint 15 is between 15 and 55 mm.

[0071] A flexible sealing tube 2 as shown in FIG. 1-4 may be produced by the method illustrated in FIGS. 5a-k. The method involves folding a flexible sealing material 2 shown in FIG. 5a into a tube-shaped flexible sealing material 2 having a first end 4 and a second end 5 as shown in FIG. 5b. The flexible sealing material has a first side 26 and a second side 27, longitudinally opposing first and second side edges 24, 25 and transverse opposing side edges 29, 30. The opposing longitudinal side edges 24, 25 of the flexible sealing material 2 are folded over the first side 26 of the flexible sealing material 2 such that they overlap each other and that a tube-shaped flexible sealing material 2 having a longitudinal direction L is formed. The longitudinal side edges 24, 25 may also extend side by side in a abutting relationship when the flexible sealing material 2 has been folded. A longitudinally extending first joint 13 is then formed, as illustrated in FIG. 5b, between the first and the second transverse side edges 29, 30, sealing the longitudinal side edges 24, 25 of the tube-shaped flexible sealing material 2 to the first side 26 of the flexible sealing material 2 such that a flexible sealing tube 2 is provided comprising a first and a second longitudinally extending channel 6, 7 separated by the longitudinally extending first joint 13. The first and second longitudinally extending channels 6, 7 each comprise a first end portion 6a, 7a and a second end portion 6b, 7b. Alternatively, the flexible sealing tube 2 may be provided in pre-sealed or in ready-made tube-shaped form prior to the step illustrated in FIG. 5b of providing a longitudinally extending first joint 13 extending from the first transverse side edge 29 to the second transverse side edge 30.

[0072] It is also conceivable that more than one longitudinally extending joint are formed such that more than two longitudinally extending channels are formed in the flexible sealing tube 2.

[0073] It is also conceivable that the opposing longitudinal side edges 24, 25 of the flexible sealing material 2 are folded over the first side 26 of the flexible sealing material 2 such that they do not overlap each other and that they do not end up in abutment with each other, but that they are positioned in opposing relationship at a distance from each other such that a tube-shaped flexible sealing material 2 having a longitudinal direction L is thus formed. The step illustrated in FIG. 5b may then take place either in a single step or in in substeps, either in parallel or in consecutive order. Each opposing longitudinal side edges 24, 25 may be sealed by a common seal, or by each one their own seal. In the latter case the longitudinally extending first joint 13 is made up by two combined seals.

[0074] FIG. 5c illustrates folding of the flexible sealing tube 2 over the longitudinally extending first joint 13 such that the flexible sealing tube 2 is in a double folded configuration. The first channel 6 has a first channel wall 16 and the second channel 7 has a second channel wall 17 as shown in FIG. 5c. The flexible sealing tube 2 may of course be folded differently, such that for example the longitudinally extending first joint 13 is located centrically in the flexible sealing tube 2.

[0075] FIG. 5d illustrates introducing welding means 19, such as electrodes, in the first and second channel 6, 7 in a first tube end 4 and FIG. 5e illustrates pressing together of the welding means 19 against the first and second channels walls 16,17 and welding together the first and second channel walls 16, 17 with a second joint 15 to form a joined welded area as illustrated in FIG. 5f. An opening 14 is subsequently punched out in the first and the second channel walls 16,17 and within the joined welded area such that the first and the second channels 6,7 are fluidly connected. As illustrated in FIG. 5g, the opening 14 is completely surrounded by the second joint 15. The opening 14 may optionally be differently designed and may be located closer or further away from the first tube end 4. The opening 14 may have a width corresponding to from 35 to 99% of the diameter of the flexible sealing tube. The opening will be designed to give a minimum passage resistance to the liquid, but still as close as possible to the first end 4.

[0076] FIG. 5h illustrates closing the flexible sealing tube 2 in the first tube end 4 and sealing the first end 4 with a third joint 18 thus forming the flexible sealing tube 2 with a closed first end 4. The third joint 18 may be a continuous joint formed by adhesive or welding, such as high frequency welding. The third joint 18 may have a different design than the one illustrated in FIG. 5h, such as for example a v-shaped joint or the first tube end 4 may be folded prior to joining the first tube end 4. The second tube end (not shown) may similarly to the first tube end 4 be provided with a fourth welding joint sealing the second tube end.

[0077] The welding may be carried out by other welding methods than high frequency welding, such as for example heat sealing, ultrasonic welding or hot plate welding. The welding may also be replaced by other methods for providing a joint, such as gluing using a glue, taping using a tape, or similar methods. It is also conceivable to combine two or more methods.

[0078] FIG. 5i illustrates the optional step of providing of the first tube end 4 with a tapering shape, the tapering shape may for example be triangular shape or a truncated triangle.

[0079] FIG. 5j illustrates the optional step of providing the first tube end 4 with a hole 20, facilitating the attachment of a load (not shown) when introducing the flexible sealing tube into a bore in the ground.

[0080] FIG. 5k illustrates the optional step of providing the walls of the first and the second channels 6,7 with valve means 11, 12 and subsequently sealing the second tube end 5 by means of welding with a fourth joint 31.

[0081] After manufacturing of the flexible sealing tube 2, the air present inside the flexible sealing tube 2 may be pressed out through the valve means 11, 12 such that the flexible sealing tube 2 may be wound up into a roll. The fact that the flexible sealing tube 2 mainly comprises flexible parts thus enables easy and convenient transport and storage of the flexible sealing tube 2. The flexible sealing tube 2 may, during installation in the bore, be connected to pipes, such as steel or plastic pipes, as illustrated in FIGS. 1a and b, to enable circulation of liquid and extraction of energy from the ground.