Low-temperature layer geothermal water heat preservation pipeline

Abstract

The low-temperature layer geothermal water heat preservation pipeline comprises an outer protection pipe and a medium pipe which are connected in a sleeved mode, multiple sets of heat preservation modules are arranged between the outer protection pipe and the medium pipe, each heat preservation module comprises an outer heat preservation layer and an inner heat preservation layer, the outer heat preservation layer is provided with an outer spiral butt joint seam, and the inner heat preservation layer is provided with an inner spiral butt joint seam. Spiral fixing strips are fixed to the outer heat preservation layer and the inner heat preservation layer, and wrapping ribs are arranged in the spiral fixing strips. The outer heat preservation layer and the inner heat preservation layer extend in a staggered mode in the axial direction and the circumferential direction, an outer axial extending layer is arranged at one end of the outer heat preservation layer, and an inner axial extending layer is arranged at one end of the inner heat preservation layer. When the heat preservation module is assembled, splicing is conducted through the outer spiral butt joint seams and the inner spiral butt joint seams, and the wrapping ribs are inserted for fixing; the foam material is injected into the injection cavity through the liquid injection port, all gaps are filled after curing, the heat preservation effect is good, and replacement and maintenance are easy.

Description

Technical Field

[0001] This application relates to the field of thermal insulation pipes, and in particular to a low-temperature geothermal water thermal insulation pipe. Background Technology

[0002] Low-temperature geothermal water is widely used in public and residential applications such as community heating, agricultural greenhouse irrigation, and hot spring therapy due to its wide distribution and low development cost. Its transportation relies on buried insulated pipes. Currently, most low-temperature geothermal water insulated pipes employ a three-layer structure: an outer protective pipe, a prefabricated insulated pipe shell, and a medium pipe. However, in practical applications, the following core technical defects exist: heat leakage and poor firmness of the spliced ​​insulation modules: most existing prefabricated insulation pipe shells are spliced ​​with axial straight seams, and the splices are only fixed by simple bonding. The gaps are prone to cracking due to soil settlement or thermal expansion and contraction of the pipes, forming "thermal bridge channels" and resulting in significant local heat loss; at the same time, the structural stability of straight seam splicing is weak, and long-term use is prone to misalignment and detachment of the insulation pipe shell, further aggravating the insulation failure.

[0003] Therefore, a low-temperature geothermal water insulation pipe is proposed. Summary of the Invention

[0004] The purpose of this application is to address the technical problems of poor robustness and serious heat leakage in existing insulation module splicing methods. Compared with the prior art, this application provides a low-temperature geothermal water insulation pipe, including an outer protective pipe and a medium pipe that are nested together. Multiple sets of insulation modules connected end to end are provided between the outer protective pipe and the medium pipe. Each insulation module includes an outer insulation layer and an inner insulation layer that are integrally structured. The outer insulation layer has an outer spiral butt joint, and the inner insulation layer has an inner spiral butt joint. Spiral fixing strips are fixed to the sides of both the outer and inner spiral butt joints. Spiral fixing strips have spiral through slots, and wrapping ribs are inserted into the spiral through slots. The outer insulation layer and the inner insulation layer extend in a staggered manner in both the axial and circumferential directions. One end of the outer insulation layer extends into an outer axial extension layer in the axial direction. The end of the inner insulation layer away from the outer axial extension layer extends into an inner axial extension layer corresponding to the outer axial extension layer. One side of the outer insulation layer extends into an outer circumferential extension layer in the circumferential direction. The side of the inner insulation layer away from the outer circumferential extension layer extends into an inner circumferential extension layer in the circumferential direction. The outer circumferential extension layer covers the outside of the inner circumferential extension layer.

[0005] Furthermore, the insulation module has an insulation base layer in the middle, which together form the inner layer of the outer insulation layer and the outer side of the inner insulation layer. Both the outer layer of the outer insulation layer and the inner layer of the inner insulation layer are provided with scratch-resistant airbag layers. An injection cavity is provided between the insulation base layer and the scratch-resistant airbag layer. Foaming material is injected into the injection cavity during use.

[0006] Furthermore, the scratch-resistant airbag layer is filled with inert gas, and the foaming material is a foaming material.

[0007] Furthermore, the outer side of the inner axial extension layer is provided with anti-detachment protrusions, and the inner side of the outer axial extension layer is provided with anti-detachment grooves that cooperate with the anti-detachment protrusions.

[0008] Furthermore, both ends of the spiral fixing strip extend to one side of the end face of the insulation module, and the end of the insulation module is provided with a seam-closing groove that matches the end of the spiral fixing strip.

[0009] Furthermore, when the two sets of media tubes are connected, the connecting ends of the two sets of outer protective tubes are covered and fixed by the protective tube encapsulation layer, and the joint between the two sets of media tubes is covered with a heat insulation module, and the connecting distance between the two sets of outer protective tubes is greater than the length of the heat insulation module.

[0010] Furthermore, the mating surfaces of the outer axial extension layer and the inner axial extension layer, the mating surfaces of the outer circumferential extension layer and the inner circumferential extension layer, and the mating surfaces of each spiral fixing strip are all coated with a thermal insulation coating.

[0011] Furthermore, the covering rib is a rigid structure, and the end of the covering rib is detachably connected to the end of the medium tube by bolts, and the bolts are provided with a ceramic heat insulation layer.

[0012] Furthermore, the structural strength of the spiral fixing strip is greater than the overall structural strength of the insulation module. The insulation module is provided with an inflation port for filling the anti-scratch airbag layer with inert gas and an injection port for filling the injection cavity with foam material.

[0013] Compared to existing technologies, the advantages of this application are: The insulation module proposed in this application is assembled by first splicing the outer spiral butt joint and the inner spiral butt joint, and then inserting the covering rib for fixation; then, foaming material is injected into the injection cavity through the injection port, and after curing, it fills all gaps; the inert gas in the anti-scratch airbag layer further blocks heat conduction, and the insulation base layer undertakes the core insulation function. The three work together to achieve efficient insulation, with good insulation effect and easy replacement and maintenance. Attached Figure Description

[0014] Figure 1 This is a schematic diagram illustrating the state of the interface encapsulation in this application; Figure 2 This is a schematic diagram of the internal structure of this application; Figure 3 This is a structural perspective view of the multiple sets of insulation modules connected together as proposed in this application; Figure 4 This is a front structural diagram of the insulation module proposed in this application; Figure 5 This is a side view of the insulation module proposed in this application; Figure 6 This is a schematic diagram of the structure of the insulation module proposed in this application when it is unfolded. Figure 7 This is a perspective view of the structure of the insulation module proposed in this application when it is unfolded. Figure 8 This is a schematic diagram showing the state in which the insulation module proposed in this application is wrapped around the medium pipe; Figure 9 This is a cross-sectional structural diagram of the insulation module proposed in this application.

[0015] Explanation of the labels in the diagram: 1. Outer protective tube; 2. Medium tube; 3. Insulation module; 301. Seam sealing groove; 302. Insulation coating; 303. Injection cavity; 304. Insulation base layer; 305. Scratch-resistant airbag layer; 306. Foaming material; 31. Outer insulation layer; 311. Outer spiral butt joint; 312. Outer axial extension layer; 313. Anti-detachment groove; 314. Outer circumferential extension layer; 32. Inner insulation layer; 321. Inner spiral butt joint; 322. Inner axial extension layer; 323. Anti-detachment protrusion; 324. Inner circumferential extension layer; 33. Spiral fixing strip; 331. Spiral through slot; 4. Covering rib; 5. Protective tube sealing layer. Detailed Implementation

[0016] The embodiments will be described clearly and completely with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments in this application without creative effort are within the scope of protection of this application.

[0017] Example: This invention provides a low-temperature geothermal water insulation pipe; please refer to [link / reference]. Figure 1 - Figure 9 The system includes an outer protective pipe 1, a medium pipe 2, and multiple sets of insulation modules 3, all of which are coaxially assembled. The outer protective pipe 1 is the outer protective structure, which in this embodiment is made of modified high-density polyethylene. Its inner diameter is adapted to the outer diameter of the insulation module 3, and it has the ability to resist soil compression. The medium pipe 2 is the geothermal water delivery channel. Multiple sets of insulation modules 3 are connected end to end and filled between the outer protective pipe 1 and the medium pipe 2 to form a continuous insulation layer, which can adapt to the construction needs of different laying scenarios. The insulation module 3 is an integrally molded structure consisting of an outer insulation layer 31 and an inner insulation layer 32, manufactured using a mold injection molding process. The main material of the insulation module 3 is based on nano-aerogel felt and composite polyurethane foam, balancing insulation performance and structural strength. The outer circumferential surface of the outer insulation layer 31 has an outer spiral butt joint 311, and the inner circumferential surface of the inner insulation layer 32 has an inner spiral butt joint 321. The two have the same pitch and the same direction of rotation, and there is a 45-degree angular deviation in the circumferential direction. A single insulation module 3 is covered and spliced ​​on the medium pipe 2 through the spiral interlocking of the outer spiral butt joint 311 and the inner spiral butt joint 321. Compared with the traditional straight seam splicing, the contact area of ​​the spiral butt joint is significantly increased, and the staggered design of the outer spiral butt joint 311 and the inner spiral butt joint 321 can greatly reduce heat leakage from gaps. Both sides of the outer spiral butt joint 311 and the inner spiral butt joint 321 are fixed with spiral fixing strips 33 by hot melting. The spiral fixing strips 33 are made of glass fiber reinforced polypropylene, and their structural strength is higher than that of the main body of the insulation module 3. Spiral slots 331 are formed inside them. After the adjacent insulation modules 3 are spliced, the wrapping ribs 4 are inserted into the spiral slots 331. Since the wrapping ribs 4 are rigid structures, the circumferential and axial fastening of the adjacent insulation modules 3 is achieved by spiral insertion, avoiding axial misalignment and enhancing the overall bending resistance of the insulation module 3. At the same time, the design of the wrapping ribs 4 can avoid the sagging gap between the insulation layer and the medium pipe 2 caused by the traditional insulation layer sagging due to gravity, further improving the insulation performance.

[0018] To further eliminate gaps at the axial joints, the outer insulation layer 31 and inner insulation layer 32 of the insulation module 3 are designed with staggered extension structures in both the axial and circumferential directions. Specifically, one end of the outer insulation layer 31 extends outward along the axial direction to form an outer axial extension layer 312, and the end of the inner insulation layer 32 away from the outer axial extension layer 312 extends inward along the axial direction to form an inner axial extension layer 322. The outer diameter of the inner axial extension layer 322 is equal to the inner diameter of the outer axial extension layer 312. When adjacent insulation modules 3 are spliced, the inner axial extension layer 322 is inserted into the outer axial extension layer 312 to form a "nested" axial connection, eliminating axial joint gaps. To prevent axial detachment, the outer circumferential surface of the inner axial extension layer 322 is provided with an annular anti-detachment protrusion 323, and the inner circumferential surface of the outer axial extension layer 312 is provided with an anti-detachment groove 313 that matches the anti-detachment protrusion 323. After the two are engaged, they can withstand sufficient axial tension to ensure a firm connection. To further eliminate gaps at the circumferential joints, one side of the outer insulation layer 31 extends outward along the circumferential direction to form an outer circumferential extension layer 314, and the side of the inner insulation layer 32 away from the outer circumferential extension layer 314 extends inward along the circumferential direction to form an inner circumferential extension layer 324. The outer diameter of the inner circumferential extension layer 324 is equal to the inner diameter of the outer circumferential extension layer 314. When the insulation module 3 is wrapped and spliced, the outer circumferential extension layer 314 covers the outside of the inner circumferential extension layer 324, forming a "wrapped" circumferential butt joint, eliminating gaps in the circumferential direction, and enhancing the integrity of the insulation layer. Please refer to this first. Figure 9 The insulation module 3 has an insulation base layer 304 in the middle, which forms the inner layer of the outer insulation layer 31 on the outside and the outer layer of the inner insulation layer 32 on the inside. It is the core insulation unit of the insulation module. Its main material is nano aerogel felt as the base material and polyurethane foam as the composite. Both the outer layer of the outer insulation layer 31 and the inner layer of the inner insulation layer 32 are equipped with a scratch-resistant airbag layer 305, which is made of weather-resistant butyl rubber. It has good elasticity and scratch resistance, can resist the scraping of soil and gravel, and at the same time buffer the deformation stress caused by the thermal expansion and contraction of the pipeline. An annular injection cavity 303 is reserved between the thermal insulation base layer 304 and the scratch-resistant airbag layer 305. After the thermal insulation module is assembled, foaming material 306 is injected into the injection cavity 303 through a special injection port. After the foaming material cures, it can fill the tiny gaps between the thermal insulation module and the outer protective tube 1 and the medium tube 2, achieving "gap-free fit". At the same time, the scratch-resistant airbag layer 305 is filled with inert gas. In this embodiment, argon gas is preferred. The low thermal conductivity of inert gas can further improve the thermal insulation effect, and the airbag structure can form a buffer protection for the thermal insulation base layer 304. Both ends of the spiral fixing strip 33 extend axially to the outer side of the end face of the insulation module 3; both ends of the insulation module 3 are provided with seam closing grooves 301 that are adapted to the ends of the spiral fixing strip 33. When adjacent insulation modules 3 are spliced, the ends of the two sets of opposing spiral fixing strips 33 are embedded in the seam closing grooves 301, which can automatically make the outer spiral butt joint 311 and the inner spiral butt joint 321 fit tightly during assembly. The mating surfaces of the outer axial extension layer 312 and the inner axial extension layer 322, the mating surfaces of the outer circumferential extension layer 314 and the inner circumferential extension layer 324, and the mating surfaces of each spiral fixing strip 33 are all coated with a thermal insulation coating 302 to further seal the tiny gaps at the mating surfaces and improve the thermal insulation integrity. In this embodiment, the thermal insulation coating 302 is preferably an inorganic silicate thermal insulation coating. When the two sets of medium pipes 2 are connected, the insulation and sealing of the connection point need to be handled simultaneously. The outer side of the connection end of the two sets of outer protective pipes 1 is covered with a protective pipe sealing layer 5, which adopts a double-layer structure. The inner layer is polyurethane waterproof membrane and the outer layer is glass fiber reinforced resin. It is bonded and fixed to the outer wall of the outer protective pipe by hot melting to achieve waterproof sealing at the connection point and prevent rainwater from seeping in. The joint of the two sets of medium pipes 2 is covered with a special insulation module 3, and the joint spacing of the two sets of outer protective pipes 1 is greater than the length of the insulation module, so as to ensure that the insulation module 3 completely covers the joint, realizes the gapless insulation of the joint, and eliminates the thermal bridge effect of the metal joint. The outer circumferential surface of the insulation module 3 is provided with two sets of interfaces. One set is an air inlet, which is connected to the anti-scratch airbag layer 305 and is used to fill the anti-scratch airbag layer with inert gas. After inflation, it is sealed by a sealing plug. The other set is a liquid injection inlet, which is connected to the injection cavity 303 and is used to inject foaming material. After injection, it is sealed by a threaded plug. Both sets of interfaces are made of corrosion-resistant plastic material to avoid corrosion from geothermal water or soil. The end of the covering rib 4 extends to the outside of the end of the medium pipe 2 and is detachably connected to the flange at the end of the medium pipe by bolts. A ceramic heat insulation layer is sleeved on the outside of the bolts to prevent the bolts from becoming thermal bridges and reduce the heat transfer to the outside through the bolts. During assembly, the insulation module 3 proposed in this application is first spliced ​​together by the outer spiral butt joint 311 and the inner spiral butt joint 321, and then fixed by the insertion of the covering rib 4; then foam material 306 is injected into the injection cavity 303 through the injection port, and after curing, it fills all gaps; the inert gas in the anti-scratch airbag layer 305 further blocks heat conduction, and the insulation base layer 304 undertakes the core insulation function. The three work together to achieve efficient insulation. Through seamless bonding, inert gas-assisted insulation, and splicing design to prevent heat leakage, the overall heat loss of the pipeline is greatly reduced, meeting the high-efficiency utilization requirements of geothermal water in low-temperature layers. The modular design facilitates manual assembly. Because foam material 306 can be temporarily filled during assembly, the insulation module 3 is small in size and easy to transport when flat, which improves the construction efficiency compared with traditional precast pipe shells. The dedicated insulation module 3 and the protective pipe sealing layer 5 at the joint simplify the joint construction. The design of the air inlet and liquid injection port facilitates the replenishment of inert gas or foam material during later maintenance. When the insulation module 3 reaches the end of its service life and needs to be replaced, the protective pipe sealing layer 5 can be removed to discharge or recover the inert gas in the anti-scratch airbag layer 305, so as to reduce the contact friction between the insulation module 3 and the outer protective pipe 1 and the medium pipe 2. At this time, the aged insulation module 3 can be directly detached from the covering rib 4 at the joint of the medium pipe 2 for replacement, thereby effectively reducing the maintenance difficulty.

[0019] The above description is only the best implementation method adopted in this application in combination with current practical needs, but the scope of protection of this application is not limited thereto.

Claims

1. A low-temperature geothermal water insulation pipe, comprising an outer protective pipe (1) and a medium pipe (2) interlocked, wherein multiple sets of end-to-end insulation modules (3) are provided between the outer protective pipe (1) and the medium pipe (2), characterized in that, The insulation module (3) includes an outer insulation layer (31) and an inner insulation layer (32) as an integral structure. The outer insulation layer (31) is provided with an outer spiral butt joint (311), and the inner insulation layer (32) is provided with an inner spiral butt joint (321). Spiral fixing strips (33) are fixed on the sides of both the outer spiral butt joint (311) and the inner spiral butt joint (321). Spiral fixing strips (33) are provided with spiral through slots (331), and covering ribs (4) are inserted into the spiral through slots (331). The outer insulation layer (31) and the inner insulation layer (32) are staggered in both the axial and circumferential directions. One end of the outer insulation layer (31) extends outward in the axial direction as an outer axial extension layer (312). The end of the inner insulation layer (32) away from the outer axial extension layer (312) extends outward in the circumferential direction as an inner axial extension layer (322) that is aligned with the outer axial extension layer (312). One side of the outer insulation layer (31) extends outward in the circumferential direction as an outer circumferential extension layer (314). The side of the inner insulation layer (32) away from the outer circumferential extension layer (314) extends outward in the circumferential direction as an inner circumferential extension layer (324). The outer circumferential extension layer (314) covers the outside of the inner circumferential extension layer (324).

2. The low-temperature geothermal water insulation pipe according to claim 1, characterized in that, The insulation module (3) has an insulation base layer (304) in the middle. The insulation base layer (304) together form the inner layer of the outer insulation layer (31) and the outer side of the inner insulation layer (32). The outer layer of the outer insulation layer (31) and the inner layer of the inner insulation layer (32) are both provided with anti-scratch airbag layers (305). An injection cavity (303) is provided between the insulation base layer (304) and the anti-scratch airbag layer (305). The injection cavity (303) is filled with foaming material (306) during use.

3. The low-temperature geothermal water insulation pipe according to claim 2, characterized in that, The scratch-resistant airbag layer (305) is filled with inert gas, and the foaming material (306) is a foaming material.

4. The low-temperature geothermal water insulation pipe according to claim 1, characterized in that, The outer side of the inner axial extension layer (322) is provided with an anti-detachment protrusion (323), and the inner side of the outer axial extension layer (312) is provided with an anti-detachment groove (313) that cooperates with the anti-detachment protrusion (323).

5. A low-temperature geothermal water insulation pipe according to claim 1, characterized in that, Both ends of the spiral fixing strip (33) extend to one side of the end face of the heat insulation module (3), and the end of the heat insulation module (3) is provided with a seam closing groove (301) that matches the end of the spiral fixing strip (33).

6. The low-temperature geothermal water insulation pipe according to claim 1, characterized in that, When the two sets of medium tubes (2) are connected, the connecting ends of the two sets of outer protective tubes (1) are covered and fixed by the protective tube encapsulation layer (5), and the connecting seam of the two sets of medium tubes (2) is covered with a heat insulation module (3). The connecting distance between the two sets of outer protective tubes (1) is greater than the length of the heat insulation module (3).

7. A low-temperature geothermal water insulation pipe according to claim 1, characterized in that, The mating surfaces of the outer axial extension layer (312) and the inner axial extension layer (322), the mating surfaces of the outer circumferential extension layer (314) and the inner circumferential extension layer (324), and the mating surfaces of each spiral fixing strip (33) are all coated with a thermal insulation coating (302).

8. A low-temperature geothermal water insulation pipe according to claim 7, characterized in that, The covering rib (4) is a rigid structure. The end of the covering rib (4) is detachably connected to the end of the medium pipe (2) by bolts. The bolts are provided with a ceramic heat insulation layer.

9. A low-temperature geothermal water insulation pipe according to claim 2, characterized in that, The structural strength of the spiral fixing strip (33) is greater than the overall structural strength of the heat insulation module (3). The heat insulation module (3) is provided with an air inlet for filling the anti-scratch airbag layer (305) with inert gas and an injection port for filling the injection cavity (303) with foaming material.

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