Temperature difference compensation anchoring connector for double-layer pipe and double-layer pipeline

Abstract

The temperature difference compensation anchoring connector comprises an outer pipe connector used for being connected with the end of an outer pipe of the double-layer pipe, and an annular inner groove is formed in the inner wall of the outer pipe connector; the inner pipe anchoring assembly comprises a hoop unit which is used for holding and fixing the inner pipe of the double-layer pipe; the at least two connecting pieces are arranged at intervals in the circumferential direction, and the first end of each connecting piece is connected with the periphery of the hoop unit; the second end of the connecting piece is provided with a clamping part, and the clamping part is clamped into the annular inner groove of the outer pipe connector, so that axial fixed connection between the inner pipe anchoring assembly and the outer pipe connector is achieved. Through the connecting piece capable of generating elastic bending deformation, axial relative displacement generated due to different thermal expansion coefficients of materials of the inner pipe and the outer pipe is actively absorbed and digested, and destructive thermal stress is converted into elastic strain energy in the connecting piece, so that stress is effectively prevented from being concentrated on a pipe body or a welding seam; the problem that the dissimilar material double-layer pipe is damaged due to temperature difference is solved.

Description

Technical Field

[0001] This invention relates to the field of pipe connection and fixing technology, and in particular to a temperature difference compensation anchor joint for double-layer pipes and a double-layer pipe. Background Technology

[0002] In many industrial sectors such as petroleum, chemical, and water supply and drainage, double-layer pipe structures are often used to achieve functions such as transportation, insulation, corrosion protection, or safety protection. Such structures usually consist of an inner pipe and an outer pipe, and the inner and outer pipes may be made of different materials with significantly different coefficients of thermal expansion, for example, the outer pipe may be made of carbon steel and the inner pipe may be made of high-density polyethylene.

[0003] When the ambient temperature or the temperature of the medium changes, the inner and outer pipes will undergo different degrees of axial deformation due to the different coefficients of thermal expansion / contraction of the two materials. Under traditional rigid connection or fixing methods, this differential deformation will be constrained, resulting in huge thermal stress at the pipe body or weld. Under long-term action, this can easily lead to pipeline fatigue damage, joint leakage, or even pipe rupture, seriously affecting the safety and service life of the pipeline system.

[0004] Currently, most solutions to this problem focus on using complex expansion joints or reserving large expansion joints. However, these methods are often structurally complex, space-consuming, and costly, and are difficult to apply at anchoring points where the inner and outer tubes need to be relatively fixed. Therefore, there is an urgent need in this field for a compact, reliable connection device that can effectively compensate for the temperature difference deformation of dissimilar double-layer tubes and achieve a firm anchoring. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a temperature difference compensation anchoring joint for double-layer pipes.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A temperature difference compensation anchoring joint for double-layer pipes, comprising: An outer pipe connector is used to connect to the outer pipe end of the double-layer pipe, and the inner wall of the outer pipe connector is provided with an annular inner groove; The inner tube anchoring assembly includes: The clamp unit is used to grip and secure the inner tube of the double-layer tube; At least two connectors are spaced apart circumferentially, and the first end of each connector is connected to the outer periphery of the clamp unit; The second end of the connector is provided with a locking part, which engages with the annular inner groove of the outer pipe joint to achieve an axial fixed connection between the inner pipe anchoring assembly and the outer pipe joint.

[0007] As a preferred embodiment of the present invention, the first end of the connector is detachably connected to the clamp unit via a first fastener.

[0008] As a preferred embodiment of the present invention, a mounting portion is further provided between the first end and the second end of the connector, and the mounting portion is detachably connected to the outer pipe joint by a second fastener.

[0009] As a preferred embodiment of the present invention, the mounting portion extends from the main body of the connector toward the inner wall of the outer pipe joint and abuts against the inner wall of the outer pipe joint.

[0010] As a preferred embodiment of the present invention, the clamp unit includes two mating semicircular clamps, which are locked together by fasteners to hold the inner tube.

[0011] As a preferred embodiment of the present invention, a serrated structure is provided on the inner wall of the semi-circular clamp.

[0012] As a preferred embodiment of the present invention, three connectors are provided and are evenly distributed along the circumference.

[0013] The present invention also discloses a double-layer piping system, including an outer pipe, an inner pipe sleeved inside the outer pipe, and a temperature difference compensation anchoring joint for the double-layer pipe as described in any one of the above, wherein the anchoring joint is connected between the ends of the inner pipe and the outer pipe.

[0014] In summary, the present invention has at least one of the following beneficial technical effects: 1. The temperature difference compensation anchoring joint for double-layer pipes of the present invention actively absorbs and digests the axial relative displacement caused by the difference in thermal expansion coefficients between the inner and outer pipe materials through a connector capable of elastic bending deformation. This converts destructive thermal stress into elastic strain energy within the connector, thereby effectively preventing stress concentration in the pipe body or weld, and fundamentally solving the problem of damage caused by temperature differences in double-layer pipes made of dissimilar materials.

[0015] 2. All compensation and anchoring components are integrated at the pipe end joint, requiring no additional installation space; the structural design is ingenious and simple. Axial locking is achieved through the engagement of the locking part and the annular inner groove, while secondary safety and a stable fulcrum are provided by the bolted connection of the mounting part, forming a robust and reliable rigid anchor.

[0016] 3. The components of the temperature difference compensation anchor joint of the present invention adopt a modular and detachable design, with a clear assembly sequence, which facilitates on-site construction, debugging and subsequent inspection and maintenance, reducing the difficulty of operation and maintenance costs.

[0017] 4. The double-layer pipe of the present invention significantly reduces the risk of fatigue damage, joint leakage or pipe rupture in the pipeline system by eliminating the destructive effects of thermal stress, thereby greatly improving the safety and service life of the entire pipeline system in long-term operation. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the temperature difference compensation anchoring joint for double-layer pipes according to the present invention.

[0019] Figure 2 This is a cross-sectional structural view of the temperature difference compensation anchor joint for double-layer pipes according to the present invention.

[0020] Figure 3 This is a structural schematic diagram illustrating the inner tube anchoring assembly of the present invention.

[0021] Explanation of reference numerals in the attached drawings: 1. Inner tube; 2. Outer tube; 3. Outer tube joint; 4. Inner tube anchoring assembly; 5. Connector; 41. First clamp; 42. Second clamp; 43. Serrated structure; 51. Engaging part; 52. First end; 53. Mounting part. Detailed Implementation

[0022] The following is in conjunction with the appendix Figure 1-3 The present invention will be described in further detail below.

[0023] Example 1 This embodiment provides a temperature difference compensation anchoring joint for double-layer pipes, which aims to solve the technical problem that the inner and outer pipes made of dissimilar materials will have axial relative displacement due to the difference in thermal expansion coefficients, which will lead to stress damage to the pipe body.

[0024] Reference Figures 1 to 3 The temperature difference compensation anchoring joint for double-layer pipes in this embodiment mainly includes an outer pipe joint 3 and an inner pipe anchoring assembly 4.

[0025] The outer tube connector 3 is used to fix and connect to the end of the outer tube 2 of the double-layer tube, for example by welding or threaded connection. The outer tube connector 3 is usually a cylindrical structure with a continuous annular inner groove 31 machined on its inner wall.

[0026] The inner tube anchoring assembly is used to fix the inner tube 1 and forms a displacement-compensating linkage connection with the outer tube joint 3. It mainly includes a clamp unit 4 and at least two connecting parts 5.

[0027] In this embodiment, the clamp unit 4 includes two mating semicircular clamps, namely a first clamp 41 and a second clamp 42. The inner walls of the two semicircular clamps (first clamp 41 and second clamp 42) may be provided with a serrated structure 43 to enhance the clamping force and anti-slip effect with the outer surface of the inner tube 1. By passing fasteners (such as bolts) through the connecting holes on the first clamp 41 and the second clamp 42 and locking them, the two semicircular clamps can tightly hold and fix the inner tube 1.

[0028] In this embodiment, the number of connectors 5 is preferably three, and they are evenly distributed circumferentially to ensure balanced force distribution. Each connector 5 is generally a long, strip-shaped plate or rod-shaped structure, and in this embodiment, it is made of a metal material with a certain degree of elasticity. Each connector 5 has a clearly defined functional part: First end 52: detachably fixed to the outer periphery of the clamp unit (first clamp 41 or second clamp 42) by means of a first fastener (such as a bolt).

[0029] The second end is provided with a locking part 51. The locking part 51 can be a structure such as a protrusion or a barb that can undergo elastic deformation.

[0030] Mounting part 53: Located between the first end 52 and the second end of the connector 5. The mounting part 53 is configured to extend (e.g., vertically) from the main body of the connector 5 toward the inner wall of the outer pipe joint 3, such that its end face can abut against the inner wall of the outer pipe joint 3. The mounting part 53 is provided with a through hole for a second fastener (such as a bolt) to pass through, thereby detachably connecting and fixing it to the wall of the outer pipe joint 3.

[0031] The temperature difference compensation anchoring joint for the double-layer pipe in this embodiment is installed in the following manner to connect the inner pipe 1 and the outer pipe 2: Pre-assembly of inner tube components: Externally, firstly, clamp the two semi-circular clamps, first clamp 41 and second clamp 42, and tighten the bolts to complete the installation of clamp unit 4. At this time, connector 5 is not installed.

[0032] Final assembly: Insert the inner tube 1, which has been fixed with clamp unit 4, into the outer tube 2 / outer tube connector 3 assembly.

[0033] Install connector 5: Finally, align the engaging part 51 of each connector 5 with the annular inner groove 31 at the end and snap it in. Then, use bolts to connect its first end 52 to the clamp unit and its mounting part 53 to the outer pipe joint 3.

[0034] When the ambient temperature or medium temperature of the piping system changes, the inner pipe 1 (such as HDPE) and the outer pipe 2 (such as carbon steel) will experience different degrees of axial expansion and contraction due to the different coefficients of thermal expansion of their materials. The anchoring joint of this invention compensates for this displacement difference through its unique design, the core of which lies in the coordinated work of three functional components: Force transmission and constraint establishment: The expansion and contraction displacement of the inner tube 1 is transmitted to the first end 52 of the connector 5 through the clamp unit 4.

[0035] The expansion and contraction displacement of the outer tube 2 is transmitted to the mounting part 53 and the engaging part 51 of the connector 5 through the outer tube joint 3.

[0036] The engaging part 51 and the annular inner groove 31 serve as a reference for positioning and axial main locking, first locking the inner and outer tube assemblies axially, thus establishing a fixed relative position reference.

[0037] Conversion and absorption of displacement difference: When the inner and outer tubes undergo relative displacement due to temperature difference, this displacement difference is converted into a force acting on the connector 5. The mounting part 53 is fixed to the outer tube joint 3 by bolts, providing a stable intermediate constraint point for the connector 5, making its deformation mode controllable.

[0038] Under the action of the aforementioned force, the connector 5 uses its own effective length segment as the deformation zone and the mounting part 53 fixing point as the main fulcrum, and undergoes a small amount of controllable elastic bending deformation.

[0039] Through the above-mentioned synergistic mechanism, destructive thermal stress is converted into elastic strain energy within the connector 5 and released, thereby preventing stress from acting directly on the inner pipe 1, outer pipe 2, or their connecting weld, greatly improving the safety and service life of the piping system. Simultaneously, the additional connection between the mounting part 53 and the outer pipe joint 3 via bolts further enhances the joint's ability to withstand shear forces and torques.

[0040] Example 2: This embodiment discloses a double-layer pipe, including an outer pipe 2, an inner pipe 1 sleeved inside the outer pipe 2, and an anchoring joint. An outer pipe joint 3 is fixed to the end of the outer pipe 2, and the outer pipe joint 3 is welded to the outer pipe 2. The anchoring joint is connected between the ends of the inner pipe 1 and the outer pipe 2. In this embodiment, the anchoring joint is the temperature difference compensation anchoring joint for double-layer pipes described in Embodiment 1.

[0041] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A temperature difference compensation anchoring joint for double-layer pipes, characterized in that, include: An outer pipe connector (3) is used to connect to the end of the outer pipe (2) of the double-layer pipe. The inner wall of the outer pipe connector (3) is provided with an annular inner groove (31). The inner tube anchoring assembly includes: Clamp unit (4) is used to clamp and fix the inner tube (1) of the double-layer tube; At least two connectors (5) are spaced apart circumferentially, and the first end of each connector (5) is connected to the outer periphery of the clamp unit; The second end of the connector (5) is provided with a locking part (51), which is engaged in the annular inner groove (31) of the outer pipe joint (3) to achieve axial fixed connection between the inner pipe anchoring assembly (4) and the outer pipe joint (3).

2. The temperature difference compensation anchoring joint for double-layer pipes according to claim 1, characterized in that, The first end (52) of the connector (5) is detachably connected to the clamp unit by a first fastener.

3. The temperature difference compensation anchoring joint for double-layer pipes according to claim 1 or 2, characterized in that, An installation part (53) is provided between the first end (52) and the second end of the connector (5), and the installation part (53) is detachably connected to the outer pipe joint (3) by a second fastener.

4. The temperature difference compensation anchoring joint for double-layer pipes according to claim 3, characterized in that: The mounting part (53) extends from the main body of the connector (5) toward the inner wall of the outer pipe joint (3) and abuts against the inner wall of the outer pipe joint (3).

5. The temperature difference compensation anchoring joint for double-layer pipes according to claim 1, characterized in that, The clamp unit includes two mating semicircular clamps, which are locked together by fasteners to hold the inner tube (1).

6. The temperature difference compensation anchoring joint for double-layer pipes according to claim 5, characterized in that, A serrated structure (43) is provided on the inner wall of the semi-circular clamp.

7. The temperature difference compensation anchoring joint for double-layer pipes according to claim 1, characterized in that, The connector (5) is provided in three parts and is evenly distributed along the circumference.

8. A double-layer piping system, characterized in that, It includes an outer tube (2), an inner tube (1) sleeved inside the outer tube (2), and a temperature difference compensation anchoring joint for a double-layer tube as described in any one of claims 1 to 7, wherein the anchoring joint is connected between the ends of the inner tube (1) and the outer tube (2).

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