Tensile composite pipe for underground heat exchange of geothermal well
By adding tensile layer and insulation layer to the composite pipe for geothermal heat exchange, and using the spiral winding structure of high-strength materials and aerogel tape, the problems of insufficient tensile strength of traditional pipes and time-consuming production of insulation layers are solved, and efficient tensile strength and insulation effect are achieved, reducing risks in downhole operation.
Patent Information
- Application Number
- CN202421975855.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-15
- Publication Date
- 2025-05-09
- Estimated Expiration
- 2034-08-15
AI Technical Summary
The tensile strength of traditional flexible composite pipes is insufficient when laid vertically under geothermal wells, which can easily lead to pipe failure. The on-site insulation layer is time-consuming and the corrosion rate of high-temperature media is fast.
A tensile composite tube for underground heat exchange in geothermal heat is designed. The structure includes an inner lining layer, a reinforcement layer, a tensile layer, an insulating layer, a heat insulation layer and an outer protective layer from the inside to the outside. The tensile layer and the insulating layer are formed by spiral winding. The tensile layer is made of high-strength material, the insulating layer is made of aerogel tape, and the outer layer is coated with an aluminum foil heat insulation layer.
The tensile strength of the pipe is increased, failure during vertical arrangement in the well is avoided, effective insulation of hot water is achieved, media temperature loss is reduced, leakage risk and corrosion damage is reduced, and on-site construction is simplified.
Smart Images
Figure CN222848891U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of composite pipes, and in particular relates to a tensile composite pipe for underground heat exchange in geothermal wells. Background Art
[0002] Geothermal energy is a new energy source that has been developing rapidly in recent years. It is a natural thermal energy extracted from the earth's crust. It comes from the molten lava inside the earth and exists in the form of thermal energy. It can heat groundwater in the strata for human use. It is a clean, efficient, renewable green resource that is widely used in national thermal pipelines, hot springs, thermal energy and other industries.
[0003] At present, steel pipes are generally used for medium transportation, but the disadvantages of steel pipes are obvious: steel pipes are supplied according to fixed lengths, with many connection parts, and are prone to leakage risks during operation; the insulation layer needs to be made on site, which consumes a lot of construction time; the corrosion rate of steel pipes is accelerated under high-temperature medium conditions, and the service life is greatly reduced. Although the use of stainless steel pipes avoids accelerated corrosion, the procurement and construction costs will increase significantly, and there is no cost saving. Therefore, it is considered to use flexible composite pipes as alternative pipes.
[0004] As a pipe material with the advantage of long-distance medium transportation, flexible composite pipe is very suitable for pumping hot water thousands of meters below the surface. However, traditional flexible composite pipes are basically used for ground transmission pipelines. When used for underground laying, it is necessary to consider that the flexible composite pipe receives downward tension in the vertical direction. The original pipe structure cannot guarantee the vertical force of the pipeline, which can easily lead to pipe failure. Therefore, it is necessary to develop a new type of pipe material that can increase tensile strength, can be used for underground heat exchange and can insulate the medium. Utility Model Content
[0005] The technical problem solved by the utility model is to provide a tensile composite pipe for geothermal underground heat exchange. The utility model aims to design a new composite pipe material which can both increase the tensile strength and insulate the medium, so as to make it suitable for underground heat exchange in the geothermal industry.
[0006] In order to achieve the above purpose, the technical solution adopted by the utility model is:
[0007] A tensile composite pipe for geothermal underground heat exchange, the structure of which includes, from inside to outside, an inner lining layer, a reinforcement layer, a tensile layer, a thermal insulation layer, a heat insulating layer and an outer protective layer; the tensile layer is formed by spirally winding a prepreg tape around the outer side of the reinforcement layer; the thermal insulation layer is made by spirally winding a thermal insulation material around the outer side of the tensile layer.
[0008] As a further limitation of the above solution, the prepreg tape of the tensile layer is spirally wound and coated on the outside of the reinforcement layer and bonded to the reinforcement layer through a heating-cooling process.
[0009] As a further limitation of the above scheme, the prepreg tape of the tensile layer is made of a high-strength material such as steel cord, steel wire or aramid fiber.
[0010] The thermal insulation material of the thermal insulation layer is an aerogel tape.
[0011] To further limit the above solution, the inner lining layer is made of high temperature resistant thermoplastic polymer material PE-RT II or PA as raw material, and the inner lining layer is extruded according to standard size through an extruder die.
[0012] As a further limitation of the above solution, the reinforcement layer is made of glass fiber prepreg tape.
[0013] As a further limitation of the above solution, the heat insulating layer is formed by wrapping the outside of the thermal insulation layer with aluminum foil.
[0014] As a further limitation of the above solution, the outer protective layer is made of high temperature resistant thermoplastic polymer material PE-RT II or PA as raw material.
[0015] The advantages of this utility model compared with the prior art:
[0016] 1. This solution adds a new insulation layer structure in the composite pipe. The insulation layer is arranged on the outside of the tensile layer. Aerogel tape is used as the insulation material and is spirally wound on the pipe body. It can insulate hot water extracted from thousands of meters underground and is suitable for underground heat exchange. A layer of aluminum foil or other materials is coated on the outside as an insulation layer to further reduce the temperature loss of the medium.
[0017] 2. This solution adds a tensile layer to the composite pipe. By using high-strength materials such as steel cords, steel wires, and aramid fibers to wrap around the outside of the reinforcement layer, the tensile strength of the pipe is increased. These high-strength materials are prefabricated in the form of prepreg tapes and spirally wound on the pipe body. They are bonded to the reinforcement layer through a heating-cooling process to form a bonded composite pipe structure, which enhances the tensile strength of the pipe and allows it to be arranged in a vertical shaft without failure during operation.
[0018] 3. The length of a single composite pipe in this solution can reach hundreds to thousands of meters, which greatly reduces the number of pipe connections and reduces the risk of leakage. The pipe body parts in contact with high-temperature media are all made of polymer materials, which can effectively resist media corrosion in high-temperature environments. The insulation layer is manufactured in the factory to reduce on-site construction. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 It is a structural schematic diagram of the utility model. DETAILED DESCRIPTION
[0020] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0021] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.
[0022] See also Figure 1 , describe the embodiments of the present utility model in detail.
[0023] Example: See Figure 1 As shown, a tensile composite pipe for geothermal underground heat exchange has a structure that includes, from the inside to the outside, an inner lining layer 1, a reinforcement layer 2, a tensile layer 3, a thermal insulation layer 4, a thermal insulation layer 5 and an outer protective layer 6; the tensile layer 3 is formed by spirally winding a prepreg tape on the outside of the reinforcement layer 2; the thermal insulation layer 4 is made by spirally winding a thermal insulation material on the outside of the tensile layer 3.
[0024] Preferably, the thermal insulation material of the thermal insulation layer 4 is an aerogel tape.
[0025] In this embodiment, a new insulation layer structure is added to the composite pipe. The insulation layer is arranged on the outside of the tensile layer. An aerogel tape is used as the insulation material and is spirally wound on the pipe body. It can insulate hot water drawn from thousands of meters underground and is suitable for underground heat exchange purposes.
[0026] A layer of aluminum foil or other materials is coated on the outside of the thermal insulation layer 4 as a thermal insulation layer 5 to further reduce the temperature loss of the medium.
[0027] In a specific embodiment, the prepreg tape of the tensile layer 3 is spirally wrapped around the outer side of the reinforcement layer 2 and bonded to the reinforcement layer 2 through a heating-cooling process to form a bonded composite tube structure. Preferably, the prepreg tape of the tensile layer 3 is made of a high-strength material of steel cord, steel wire or aramid fiber.
[0028] In this embodiment, a tensile layer is added outside the reinforcement layer to enhance the tensile strength of the pipe, so that it can be arranged in a vertical shaft without failure during operation.
[0029] The inner lining layer 1 is made of high temperature resistant thermoplastic polymer material PE-RT II or PA as raw material, and the inner lining layer 1 is extruded according to standard size through an extruder die. The reinforcing layer 2 is made of glass fiber prepreg tape. The outer protective layer 6 is also made of high temperature resistant thermoplastic polymer material PE-RT II or PA as raw material.
[0030] Compared with traditional flexible composite pipes, this tensile-resistant composite pipe adds an insulation layer and an anti-tensile layer structure on the basis of traditional flexible composite pipes. The insulation layer structure can insulate hot water extracted from the ground and is suitable for underground heat exchange purposes. The tensile strength of the pipe is enhanced by the anti-tensile layer structure, which can prevent the pipeline from being subjected to excessive tension when it is arranged vertically in the well, causing the pipe body to fail.
[0031] The length of a single tensile composite pipe can reach hundreds to thousands of meters, which greatly reduces the number of pipe connections and reduces the risk of leakage. The pipe body parts in contact with high-temperature media are all made of polymer materials, which can effectively resist media corrosion in high-temperature environments. The insulation layer is manufactured in the factory to reduce on-site construction workload.
[0032] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any reference numeral in a claim should not be regarded as limiting the claim to which it relates.
[0033] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.
Claims
1. Tensile composite pipe for underground heat exchange, characterized by: The structure of the tensile composite pipe comprises, from the inside to the outside, an inner lining layer (1), a reinforcement layer (2), a tensile layer (3), a thermal insulation layer (4), a heat insulating layer (5) and an outer protective layer (6); the tensile layer (3) is formed by spirally winding a prepreg tape on the outer side of the reinforcement layer (2); and the thermal insulation layer (4) is made by spirally winding a thermal insulation material on the outer side of the tensile layer (3).
2. The tensile-resistant composite pipe for underground heat exchange according to claim 1, characterized in that: The prepreg tape of the tensile layer (3) is spirally wound and coated on the outside of the reinforcing layer (2) and is bonded to the reinforcing layer (2) through a heating-cooling process.
3. The tensile-resistant composite pipe for underground heat exchange according to claim 2 is characterized in that: The prepreg tape of the tensile layer (3) is made of high-strength material such as steel cords, steel wires or aramid fibers.
4. The tensile-resistant composite pipe for underground heat exchange according to claim 1, characterized in that: The thermal insulation material of the thermal insulation layer (4) is an aerogel tape.
5. The tensile-resistant composite pipe for underground heat exchange according to claim 1, characterized in that: The inner lining layer (1) is made of high temperature resistant thermoplastic polymer material PE-RT II or PA as raw material, and the inner lining layer (1) is extruded into a standard size through an extruder die.
6. The tensile-resistant composite pipe for underground heat exchange according to claim 1, characterized in that: The reinforcement layer (2) is made of glass fiber prepreg tape.
7. The tensile-resistant composite pipe for underground heat exchange according to claim 1, characterized in that: The heat insulating layer (5) is formed by wrapping the outside of the heat preservation layer (4) with aluminum foil.
8. The tensile-resistant composite pipe for underground heat exchange according to claim 1, characterized in that: The outer protective layer (6) is made of high temperature resistant thermoplastic polymer material PE-RT II or PA as raw material.