Compensation device for direct-buried heating pipeline

Abstract

The application provides a compensation device for a directly-buried heat supply pipeline, which comprises a fixed joint assembly and an expansion joint assembly connected together, the fixed joint assembly comprises a fixed inner pipe, a fixed outer pipe and a ring plate assembly, the ring plate assembly is arranged between the fixed inner pipe and the fixed outer pipe, the expansion joint assembly comprises a first end pipe, a second end pipe and a bellows assembly, the bellows assembly is arranged between the first end pipe and the second end pipe, the fixed outer pipe comprises a first fixed outer pipe and a second fixed outer pipe, a steel-plastic connecting assembly is arranged at the left end of the first fixed outer pipe, the steel-plastic connecting assembly comprises a guide sleeve and a polyethylene pipe, the guide sleeve is installed on the inner side of the left end of the fixed outer pipe, and the polyethylene pipe is installed on the outside of the guide sleeve; the application realizes integrated design of the fixed joint and the expansion joint, reduces the number of interfaces with the heat supply pipeline, simplifies the construction steps, reduces the construction difficulty, and makes the construction of the connection between the compensation device and the outer pipe of the field heat preservation pipe more convenient.

Description

Technical Field

[0001] This invention relates to the field of compensation technology used in the long-distance heating industry, and more specifically, to a compensation device for directly buried heating pipelines. Background Technology

[0002] When heating pipelines are directly buried and a compensation design is adopted, stress in the pipeline is generally reduced by installing corrugated metal expansion joints. When arranging corrugated metal expansion joints, fixed joints are often installed on the pipeline to divide the pipe sections. Main fixed joints are often required near elbows. The corrugated metal expansion joints near elbows generally use an external pressure axial structure, with one end being a fixed end, located next to the fixed joint, and the other end being a sliding end to absorb pipeline displacement. After the corrugated metal expansion joint is transported to the site, the fixed end needs to be connected to the steel pipe of the fixed joint, and the sliding end needs to be connected to the insulation pipe of the heating pipeline.

[0003] Currently, the following problems exist when using metal corrugated expansion joints for compensation in large-diameter directly buried heating pipelines: First, the ends of existing fixed joints and expansion joints are often made of steel pipes, while the outermost layer of the insulation pipes commonly used in hot water heating pipelines is made of polyethylene. When performing on-site jointing between the steel pipes of the fixed joints and expansion joints and the polyethylene outer protective pipe of the hot water pipeline, there are construction difficulties due to the connection of two dissimilar materials. If the construction quality at the connection is substandard, it can easily lead to leakage at the connection point later, resulting in corrosion and damage to the insulation layer. Second, the anchoring points of large-diameter pipelines, which rely entirely on soil anchoring, will shift during operation as soil friction decreases, causing excessive deformation and damage to the corrugated pipe. Third, the metal... The corrugated expansion joint itself does not have a fixing function. After being transported to the site, one end of its corrugated pipe assembly is connected to the heating pipeline to achieve the displacement compensation function, and the other end is connected to the fixed section that has already been installed on site to achieve the fixing function. Fourth, direct-buried heating pipelines often use three-in-one insulated pipes. The inner side of this insulated pipe is a steel pipe, and the outer side is a polyethylene pipe. After the fixed section and expansion joint arrive at the site, they need to be connected to the heating pipeline respectively. During the connection, the inner pipe needs to be welded first. In order to realize the welding of the inner pipe and non-destructive testing, a 200-400mm notch needs to be reserved at the corresponding position of the outer pipe of the fixed section and expansion joint. After the inner pipe is welded, this notch is treated on the outside, which is also called joint filling treatment. When filling, a heat fusion sleeve needs to be installed on the outside of the notch, overlapping the outer pipe of the fixed section and expansion joint respectively, and finally sealing treatment is performed. The current installation method involves three joint treatments: the interface between the fixed section and the heating pipe, the interface between the fixed section and the expansion joint, and the interface between the expansion joint and the heating pipe. This results in a large amount of on-site construction work and makes it difficult to guarantee the quality. Summary of the Invention

[0004] In view of this, the present invention aims to propose a compensation device for directly buried heating pipelines. One problem it solves is the difficulty in connecting dissimilar materials such as steel pipes and polyethylene pipes during on-site installation of fixed sections and expansion joints with the heating pipeline. Another problem it solves is the large number of joints, extensive joint construction, cumbersome construction steps, and low quality reliability of the fixed sections and expansion joints for directly buried heating pipelines during on-site installation. A third problem it solves is that the anchor points are prone to movement, leading to excessive deformation and damage to the corrugated pipe.

[0005] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0006] A compensation device for a directly buried heating pipeline includes a fixed joint assembly and an expansion joint assembly connected together. The fixed joint assembly includes a fixed inner pipe, a fixed outer pipe, and a ring plate assembly. The ring plate assembly is disposed between the fixed inner pipe and the fixed outer pipe and is used for limiting and fixing the fixed inner pipe and the fixed outer pipe. The expansion joint assembly includes a first end pipe, a second end pipe, and a bellows assembly. The bellows assembly is disposed between the first end pipe and the second end pipe and is used to absorb the deformation generated by the heating pipeline during operation.

[0007] The fixed outer tube includes a first fixed outer tube and a second fixed outer tube, which are welded together. A steel-plastic connecting assembly is provided at the left end of the first fixed outer tube. The steel-plastic connecting assembly includes a guide sleeve and a polyethylene tube. The guide sleeve is installed inside the left end of the fixed outer tube, and the polyethylene tube is installed outside the guide sleeve and abuts against the left end of the fixed outer tube.

[0008] The compensation device for directly buried heating pipelines described in this application combines a fixed joint assembly and an expansion joint assembly, achieving the dual functions of displacement compensation and self-fixation. This improves the stability and reliability of the directly buried heating pipeline operation, extends the life of the expansion joint assembly, and reduces heat loss and stress concentration at the fixed joint assembly, enabling the heating pipeline to operate stably for a long period. The steel-plastic connection design allows the compensation device to have a built-in polyethylene pipe at the port, facilitating interface processing with the polyethylene outer pipe of the on-site insulation pipe, simplifying the construction steps, reducing construction difficulty, and enhancing the sealing reliability of the connection between the fixed joint assembly and the pipeline, as well as the quality reliability of the compensation device.

[0009] Furthermore, the steel-plastic connection assembly also includes a heat-expanding strip, which is disposed on the outside of the fixed outer tube and covers the interface between the polyethylene tube and the fixed outer tube for sealing the interface.

[0010] The material of the heat-expanding tape has a certain degree of thermal expansion, which can automatically adjust its length when the pipe temperature changes. It adapts to the expansion and contraction of the pipe caused by temperature changes, maintains the sealing performance of the joint, prevents media leakage and the entry of external substances into the pipe, and avoids stress concentration and damage to the pipe caused by temperature changes. It also makes the construction of the connection between the fixed joint assembly and the pipe more convenient. Simply wrap the heat-expanding tape at the joint between the polyethylene pipe and the fixed outer pipe to achieve the joint seal, reducing construction steps and process requirements.

[0011] Furthermore, the outer wall of the guide sleeve is coated with hot melt adhesive, which is used to enhance the bonding strength between the guide sleeve and the polyethylene pipe.

[0012] After curing, hot melt adhesive forms a strong bonding layer, making the connection between the guide sleeve and the polyethylene pipe more secure and reducing the risk of loosening and detachment. Hot melt adhesive can fill the tiny gaps between the guide sleeve and the polyethylene pipe, preventing media leakage and the entry of external substances into the pipeline, thus improving the safety and reliability of the pipeline system. Hot melt adhesive has good high temperature resistance and can maintain stable performance in high temperature environments, enabling the connection between the guide sleeve and the polyethylene pipe to work stably for a long time under high temperature conditions without structural loosening or failure due to temperature changes.

[0013] Furthermore, the ring plate assembly includes an inner ring plate and an outer ring plate. The inner ring plate includes a first inner ring plate and a second inner ring plate, and the outer ring plate includes a first outer ring plate and a second outer ring plate. The first inner ring plate and the second inner ring plate are disposed on the outer wall of the fixed inner tube, and the first outer ring plate and the second outer ring plate are disposed on the inner wall of the fixed outer tube. A gap is left between the inner ring plate and the fixed outer tube, and a gap is left between the outer ring plate and the fixed inner tube. The inner ring plate is located between the first outer ring plate and the second outer ring plate. The inner ring plate and the outer ring plate cooperate to limit and fix the fixed inner tube.

[0014] The corrugated pipe assembly includes a corrugated pipe, a first connecting pipe, and a second connecting pipe. The left end of the corrugated pipe is connected to a first end pipe through the first connecting pipe, and the right end is connected to a second end ring plate through the second connecting pipe. The second end ring plate and the second end pipe are fixed together. An clearance gap is provided between the left end of the first connecting pipe, the first end pipe, and the first end ring plate to absorb the deformation of the corrugated pipe assembly.

[0015] This design achieves both the limiting and fixing of the inner and outer tubes, ensuring the stability and safety of the ring plate assembly, and avoids direct contact between the inner and outer tubes, reducing heat transfer. It also makes the entire system more adaptable to dynamic working environments and prevents excessive stress concentration.

[0016] Furthermore, a first gap is provided between the first outer ring plate and the first inner ring plate, and the first gap is filled with a first heat insulation layer to isolate heat transfer between the first outer ring plate and the first inner ring plate; a second gap is provided between the second outer ring plate and the second inner ring plate, and the second gap is filled with a second heat insulation layer to isolate heat transfer between the second outer ring plate and the second inner ring plate.

[0017] This design effectively blocks heat transfer between the inner and outer ring plates, reduces heat loss at the fixed joint assembly, and improves insulation performance.

[0018] Furthermore, a reinforcing ring plate is provided between the fixed inner tube and the fixed outer tube. The reinforcing ring plate is located between the first inner ring plate and the second inner ring plate, and the reinforcing ring plate is used to enhance the strength of the inner ring plate.

[0019] This design effectively enhances the strength of the inner ring plate, improves the overall stability and load-bearing capacity of the ring plate assembly, and prevents deformation or failure of the fixing function due to insufficient strength of the ring plate assembly.

[0020] Furthermore, the outer wall of the fixed outer tube is uniformly provided with multiple seamless tubes, which are used to enhance the connection between the fixed outer tube and the external concrete.

[0021] This design not only enhances the connection between the fixed outer tube and the concrete, improving the overall stability of the fixed section assembly, but also, due to the small diameter of the seamless tube and the small contact area with the concrete, effectively reduces stress concentration and avoids weld cracking and concrete cracking at the fixed section assembly.

[0022] Furthermore, the expansion joint assembly also includes a limiting device, which is located on the right side of the second end ring plate and is used to limit the bellows assembly. The limiting device includes a limiting block, a third end ring plate, and a limiting outer tube. The lower end of the third end ring plate is connected to the outer wall of the first end tube, and the upper end is connected to the limiting outer tube. The limiting block is located at the left end of the third end ring plate.

[0023] This setting can control the displacement range of the bellows assembly, avoid excessive displacement of the bellows assembly, help protect the normal operation of the bellows assembly, and avoid unnecessary damage to the pipeline system.

[0024] Furthermore, the expansion joint assembly also includes an outer casing. The left end of the outer casing is connected to the second fixed outer tube via a first insulation ring plate and a second fixed outer tube, and the right end is connected to the second end tube via a second insulation ring plate. A sealing block is provided at the lower end of the second insulation ring plate, and the second insulation ring plate can slide on the outer wall of the limiting outer tube via the sealing block.

[0025] This design achieves both thermal insulation of the outer tube and the outer end tube of the expansion joint assembly, and sliding expansion and contraction of the external thermal insulation structure of the connecting end tube of the corrugated pipe assembly. This ensures the integrity and sealing of the thermal insulation structure at the connected end tube when the corrugated pipe assembly expands and contracts, and avoids compression damage caused by the outer thermal insulation of the end tube not expanding and contracting with the corrugated pipe assembly.

[0026] Furthermore, the gaps between the polyethylene pipe and the fixed inner pipe, the gaps between the fixed outer pipe and the fixed inner pipe, the gaps between the outer protective sleeve and the second end pipe, and the gaps between the limiting outer pipe and the first end pipe are filled with polyurethane foam.

[0027] This design creates a sealed insulation layer, which effectively improves the insulation performance of the pipeline, reduces heat transfer and loss, increases the pipeline's thermal efficiency, and effectively prevents media leakage and the entry of external substances into the pipeline. At the same time, the polyurethane foam filling can improve the strength of the fixed joint assembly and expansion joint assembly, reduce the vibration and deformation of the pipeline during operation, and extend the service life of the pipeline.

[0028] Compared with existing technologies, the compensation device for directly buried heating pipelines described in this invention has the following advantages:

[0029] 1) The construction steps have been simplified and the construction difficulty has been reduced, making the construction of the connection between the compensation device and the external pipe of the on-site insulation pipe more convenient, and enhancing the sealing reliability of the connection between the compensation device and the heating pipeline as well as the quality reliability of the compensation device.

[0030] 2) It achieves an integrated design of both fixed joints and expansion joints, reducing the number of interfaces with heating pipelines and reducing on-site construction workload;

[0031] 3) It can prevent excessive deformation of the bellows and improve the service life of the compensation device under abnormal working conditions;

[0032] 4) It effectively blocked some thermal bridges, reduced heat loss at the fixed section assembly, and effectively reduced stress concentration at the contact point with concrete, thus avoiding weld cracking and concrete cracking at the fixed section assembly. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the compensation device structure for the direct-buried heating pipeline according to an embodiment of the present invention;

[0034] Figure 2 for Figure 1 A partial structural diagram of the compensation device;

[0035] Figure 3 for Figure 2 A partial structural diagram of the middle fixed section assembly;

[0036] Figure 4 for Figure 2 A partial structural diagram of the steel-plastic connection assembly.

[0037] Explanation of reference numerals in the attached figures:

[0038] 1. Fixed joint assembly; 11. Fixed inner tube; 12. Fixed outer tube; 121. First fixed outer tube; 122. Second fixed outer tube; 13. Ring plate assembly; 131. Inner ring plate; 1311. First inner ring plate; 1312. Second inner ring plate; 132. Outer ring plate; 1321. First outer ring plate; 1322. Second outer ring plate; 14. Reinforcing ring plate; 15. Seamless tube; 2. Expansion joint assembly; 21. First end tube; 22. Second end tube; 23. Bellows. Components; 231, Corrugated pipe; 241, First connecting pipe; 242, Second connecting pipe; 251, First end ring plate; 252, Second end ring plate; 253, Third end ring plate; 26, Clearance clearance; 27, Limiting device; 271, Limiting block; 272, Limiting outer pipe; 28, Outer protective sleeve; 3, Steel-plastic connection assembly; 31, Guide sleeve; 32, Polyethylene pipe; 33, Thermal expansion strip; 41, First insulation ring plate; 42, Second insulation ring plate; 421, Sealing block. Detailed Implementation

[0039] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0040] Example 1

[0041] like Figure 1-4 As shown, a compensation device for a directly buried heating pipeline includes a fixed joint assembly 1 and an expansion joint assembly 2 connected together. The fixed joint assembly 1 includes a fixed inner pipe 11, a fixed outer pipe 12, and a ring plate assembly 13. The ring plate assembly 13 is disposed between the fixed inner pipe 11 and the fixed outer pipe 12, and is used to limit and fix the inner pipe 11 and the fixed outer pipe 12. The expansion joint assembly 2 includes a first end pipe 21, a second end pipe 22, and a corrugated pipe assembly 23. The corrugated pipe assembly 23 is disposed between the first end pipe 21 and the second end pipe 22, and is used to absorb the deformation generated by the heating pipeline during operation.

[0042] The ring plate assembly 13 includes an inner ring plate 131 and an outer ring plate 132. The inner ring plate 131 includes a first inner ring plate 1311 and a second inner ring plate 1312. The outer ring plate 132 includes a first outer ring plate 1321 and a second outer ring plate 1322. The first inner ring plate 1311 and the second inner ring plate 1312 are disposed on the outer wall of the fixed inner tube 11. The first outer ring plate 1321 and the second outer ring plate 1322 are disposed on the inner wall of the fixed outer tube 12. A gap is left between the inner ring plate 131 and the fixed outer tube 12, and a gap is left between the outer ring plate 132 and the fixed inner tube 11. The inner ring plate 131 is located between the first outer ring plate 1321 and the second outer ring plate 1322. The inner ring plate 131 and the outer ring plate 132 cooperate to limit and fix the fixed inner tube 11.

[0043] The corrugated pipe assembly 23 includes a corrugated pipe 231, a first connector 241, and a second connector 242. The left end of the corrugated pipe 231 is connected to a first end pipe 21 via the first connector 241, and the right end is connected to a second end ring plate 252 via the second connector 242. The second end ring plate 252 and the second end pipe 22 are fixed together. A clearance gap 26 is provided between the left end of the first connector 241 and the first end pipe 21 and the first end ring plate 251 to absorb the deformation of the corrugated pipe assembly 23.

[0044] The compensation device for the direct-buried heating pipeline described in this application combines the fixed joint assembly 1 and the expansion joint assembly 2, achieving the dual functions of displacement compensation and self-fixation. This improves the stability and reliability of the direct-buried heating pipeline operation, extends the life of the expansion joint assembly 2, and reduces heat loss and stress concentration at the fixed joint assembly 1, enabling the heating pipeline to operate stably for a long period. By setting the inner ring plate 131 and the outer ring plate 132, the limiting fixation between the fixed inner pipe 11 and the fixed outer pipe 12 is achieved, ensuring the stability and safety of the ring plate assembly 13. It also avoids direct contact between the fixed inner pipe 11 and the fixed outer pipe 12, reducing heat transfer. During operation, the pipeline may experience displacement due to temperature, pressure, or other factors. The bellows assembly 23 can absorb these changes, making the entire system more adaptable to the dynamic working environment. The clearance 26 further enhances flexibility, allowing the bellows assembly 23 to move in a specific direction and preventing excessive stress concentration.

[0045] The compensation device achieves displacement compensation through the bellows assembly 23.

[0046] Preferably, the right end of the fixed joint assembly 1 is connected to the expansion joint assembly 2 via the first end ring plate 251.

[0047] As a preferred example of this application, a first gap is provided between the first outer ring plate 1321 and the first inner ring plate 1311, and the first gap is filled with a first heat insulation layer to isolate heat transfer between the first outer ring plate 1321 and the first inner ring plate 1311; a second gap is provided between the second outer ring plate 1322 and the second inner ring plate 1312, and the second gap is filled with a second heat insulation layer to isolate heat transfer between the second outer ring plate 1322 and the second inner ring plate 1312.

[0048] Specifically, this arrangement can effectively block heat transfer between the inner ring plate 131 and the outer ring plate 132, reduce heat loss at the fixed joint assembly 1, and improve the insulation effect.

[0049] Preferably, the first and second insulation layers are made of rigid insulation materials.

[0050] As a preferred example of this application, a reinforcing ring plate 14 is provided between the fixed inner tube 11 and the fixed outer tube 12. The reinforcing ring plate 14 is located between the first inner ring plate 1311 and the second inner ring plate 1312, and the reinforcing ring plate 14 is used to enhance the strength of the inner ring plate 131.

[0051] Specifically, by setting the reinforcing ring plate 14, the strength of the inner ring plate 131 can be effectively enhanced, the overall stability and load-bearing capacity of the ring plate assembly 13 can be improved, and the ring plate assembly can be prevented from deforming and failing due to insufficient strength.

[0052] As a preferred example of this application, the outer wall of the fixed outer tube 12 is uniformly provided with a plurality of seamless tubes 15, which are used to enhance the connection between the fixed outer tube 12 and the external concrete.

[0053] Specifically, this design not only enhances the connection between the fixed outer tube 12 and the concrete, improving the overall stability of the fixed section assembly 1, but also reduces stress concentration due to the small diameter of the seamless tube 15 and the small contact area with the concrete, thus preventing weld cracking and concrete cracking at the fixed section assembly 1.

[0054] Preferably, the diameter of the seamless tube 15 is greater than or equal to 20 mm.

[0055] Example 2

[0056] like Figure 1-4As shown, as a preferred example of this application, the fixed outer tube 12 includes a first fixed outer tube 121 and a second fixed outer tube 122, which are welded together. The first outer ring plate 1321 is disposed on the inner wall of the first fixed outer tube 121, and the second outer ring plate 1322 is disposed on the inner wall of the second fixed outer tube 122. A steel-plastic connecting assembly 3 is provided at the left end of the first fixed outer tube 121. The steel-plastic connecting assembly 3 includes a guide sleeve 31 and a polyethylene pipe 32. The guide sleeve 31 is installed on the inner side of the left end of the fixed outer tube 12, and the polyethylene pipe 32 is installed on the outside of the guide sleeve 31 and abuts against the left end of the fixed outer tube 12.

[0057] Specifically, before the compensation device leaves the factory, the first fixed outer pipe 121 has been equipped with the first outer ring plate 1321, the second fixed outer pipe 122 has been equipped with the second outer ring plate 1322, the right end of the first fixed outer pipe 121 and the left end of the second fixed outer pipe 122 have been welded together, and the steel-plastic connection assembly 3 has been installed on the left end of the first fixed outer pipe 121, making the construction of the connection between the fixed section assembly 1 and the pipeline more convenient. Polyethylene pipe 32 serves as the outer protective pipe of the fixed outer pipe 12. It is made of the same material as the outer polyethylene protective pipe of the on-site heating and insulation pipe, making it easy to achieve a tight connection with the pipe insulation structure. When installing with the on-site pipe, it is only necessary to connect the end polyethylene pipe 32 to the outer polyethylene protective pipe of the heating and insulation pipe. The ring plate assembly 13 realizes the fixing function of the inner and outer steel pipes of the fixed section assembly 1. The steel-plastic connection setting realizes that the compensation device port has its own polyethylene pipe 32, which facilitates the interface treatment with the polyethylene outer pipe of the on-site insulation pipe, simplifies the construction steps, reduces the construction difficulty, and enhances the sealing reliability of the fixed section assembly 1 and the pipe connection, as well as the quality reliability of the compensation device, which can prevent water leakage at the pipe connection.

[0058] It should be noted here that the fixed joint assembly 1 and the expansion joint assembly 2 are not simply connected directly. Direct connection would prevent welding of the inner tube. To ensure welding of the inner tube, a notch needs to be reserved in the outer tube, and this notch requires external patching, which necessitates the use of an outer steel pipe or a hot-melt sleeve. This process is no different from assembling the two separately on-site. However, the compensation device described in this invention, through innovative structural design, achieves functional integration of the fixed joint and the expansion joint, and the connection between the two does not require patching; both are welded connections. The fixed joint assembly 1 and the expansion joint assembly 2 share a fixed inner tube 11. A pre-reserved closure joint is provided in the first fixed outer tube 121 and the second fixed outer tube 122. The first inner ring plate 1311 and the second inner ring plate 1312 are first welded to the fixed inner tube 11. The first outer ring plate 1321 is welded to the first fixed outer tube 121 to form the first fixed outer tube assembly. The second outer ring plate 1322 is welded to the second fixed outer tube 122 to form the second fixed outer tube assembly. After the second fixed outer tube assembly is welded to the expansion joint assembly 2, the first fixed outer tube assembly is assembled, thus achieving the connection of the closure joint and the installation of the inner and outer ring plates. The compensation device is a one-piece structure at the factory, solving the problems of low on-site construction efficiency, numerous interfaces, and large workload caused by the fixed joint and expansion joint being manufactured and supplied by different manufacturers. In addition, by using the compensation device described in this article, during on-site installation, it is only necessary to connect the steel-plastic connection components 3 at both ends of the compensation device to the pipe opening of the heating pipeline. This solves the problem of connecting dissimilar materials of steel pipe and polyethylene outer pipe of insulation pipe on site, reduces on-site construction difficulty, and shortens the construction period.

[0059] Preferably, the compensation device is provided with steel-plastic connecting components 3 at both the left and right ends.

[0060] As a preferred example of this application, the steel-plastic connection assembly 3 further includes a heat-expanding strip 33, which is disposed outside the fixed outer tube 12 and covers the interface between the polyethylene tube 32 and the fixed outer tube 12 for sealing the interface.

[0061] Specifically, the material of the thermal expansion band 33 has a certain thermal expansion property, which can automatically adjust its length when the pipe temperature changes, adapt to the expansion and contraction of the pipe caused by temperature changes, maintain the sealing performance of the interface, prevent media leakage and external substances from entering the pipe, and avoid stress concentration and damage to the pipe caused by temperature changes. It also makes the construction of the connection between the fixed joint assembly 1 and the pipe more convenient. The interface can be sealed simply by wrapping the thermal expansion band 33 at the interface between the polyethylene pipe 32 and the fixed outer pipe 12, reducing the construction steps and process requirements.

[0062] As a preferred example of this application, the outer wall of the guide sleeve 31 is coated with hot melt adhesive, which is used to enhance the bonding strength between the guide sleeve 31 and the polyethylene pipe 32.

[0063] Specifically, after curing, the hot melt adhesive forms a strong bonding layer, making the connection between the guide sleeve 31 and the polyethylene pipe 32 more secure and reducing the risk of loosening and falling off. The hot melt adhesive can fill the tiny gaps between the guide sleeve 31 and the polyethylene pipe 32, preventing media leakage and the entry of external substances into the pipeline, thus improving the safety and reliability of the pipeline system. The hot melt adhesive has good high temperature resistance and can maintain stable performance in high temperature environments, enabling the connection between the guide sleeve 31 and the polyethylene pipe 32 to work stably for a long time under high temperature conditions without structural loosening or failure due to temperature changes.

[0064] As a preferred example of this application, the expansion joint assembly 2 further includes a limiting device 27, which is disposed on the right side of the second end ring plate 252 and is used to limit the bellows assembly 23. The limiting device 27 includes a limiting block 271, a third end ring plate 253 and a limiting outer tube 272. The lower end of the third end ring plate 253 is connected to the outer wall of the first end tube 21, and the upper end is connected to the limiting outer tube 272. The limiting block 271 is disposed on the left end of the third end ring plate 253.

[0065] Specifically, by limiting the bellows assembly 23 with the limiting device 27, the displacement range of the bellows assembly 23 can be controlled, excessive displacement of the bellows assembly 23 can be avoided, which helps to protect the normal operation of the bellows assembly 23 and avoid unnecessary damage to the pipeline system.

[0066] As a preferred example of this application, the expansion joint assembly 2 further includes an outer protective sleeve 28. The left end of the outer protective sleeve 28 is connected to the first heat-insulating ring plate 41 and the second fixed outer tube 122, and the right end is connected to the second heat-insulating ring plate 42 and the second end tube 22. A sealing block 421 is provided at the lower end of the second heat-insulating ring plate 42, and the second heat-insulating ring plate 42 can slide on the outer wall of the limiting outer tube 272 through the sealing block 421.

[0067] Specifically, the outer casing 28 provides additional protection and support, enhancing the structural stability and insulation of the expansion joint assembly 2. It protects the expansion joint assembly 2 from external environmental influences, extending its service life. By setting a sealing block 421 at the lower end of the second insulation ring plate 42, the second insulation ring plate 42 can slide on the outer wall of the limiting outer tube 272. This design facilitates the sliding expansion and contraction of the bellows assembly 23 while maintaining its sealing performance, ensuring the normal operation of the system. This setting achieves insulation of the outer tube and end tube of the expansion joint assembly 2, and also enables the sliding expansion and contraction of the external insulation structure of the connecting end tube of the bellows assembly 23. It ensures the integrity and sealing of the insulation structure at the connected end tube when the bellows assembly 23 expands and deforms, avoiding the compression damage caused by the insulation on the outside of the end tube not expanding and contracting with the bellows assembly 23.

[0068] As a preferred example of this application, the gap between the polyethylene pipe 32 and the fixed inner pipe 11, the gap between the fixed outer pipe 12 and the fixed inner pipe 11, the gap between the outer protective sleeve 28 and the second end pipe 22, and the gap between the limiting outer pipe 272 and the first end pipe 21 are filled with polyurethane foam.

[0069] Specifically, this setup can form a sealed insulation layer, which can effectively improve the insulation performance of the pipeline, reduce heat transfer and loss, improve the thermal efficiency of the pipeline, and effectively prevent media leakage and external substances from entering the pipeline. At the same time, the polyurethane foam filling can improve the strength of the fixed joint assembly 1 and the expansion joint assembly 2, reduce the vibration and deformation of the pipeline during operation, and extend the service life of the pipeline.

[0070] Compared with existing technologies, the compensation device for directly buried heating pipelines described in this application has the following advantages: 1) The steel-plastic connection design at both ends of the compensation device simplifies the construction steps, reduces construction difficulty, makes the construction of the connection between the compensation device and the on-site insulation pipe more convenient, and enhances the sealing reliability of the connection between the compensation device and the heating pipeline, as well as the quality reliability of the compensation device; 2) The compensation device has both fixing and displacement compensation functions, realizing the integrated design of the fixed section and the expansion joint, reducing the number of interfaces with the heating pipeline, and reducing the on-site construction workload; 3) The compensation device has limited... The positioning function can prevent excessive deformation of the corrugated pipe 231 and improve the service life of the compensation device under abnormal working conditions; 4) It effectively blocks some thermal bridges, reduces heat loss at the fixed section assembly 1, and effectively reduces stress concentration at the contact point with concrete, avoiding weld cracking and concrete cracking at the fixed section assembly 1; 5) It realizes the sliding expansion and contraction of the external insulation structure of the first end pipe 21 connected to the corrugated pipe assembly 23, ensuring the integrity and sealing of the external insulation structure of the first end pipe 21 when the corrugated pipe assembly 23 expands and contracts, and avoiding the squeezing damage caused by the external insulation not expanding and contracting with the corrugated pipe assembly 23.

[0071] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A compensation device for a directly buried heating pipeline, characterized in that, The system includes a fixed joint assembly (1) and an expansion joint assembly (2) connected together. The fixed joint assembly (1) includes a fixed inner pipe (11), a fixed outer pipe (12), and an annular plate assembly (13). The annular plate assembly (13) is disposed between the fixed inner pipe (11) and the fixed outer pipe (12) and is used to limit and fix the inner pipe (11) and the fixed outer pipe (12). The expansion joint assembly (2) includes a first end pipe (21), a second end pipe (22), and a bellows assembly (23). The bellows assembly (23) is disposed between the first end pipe (21) and the second end pipe (22) and is used to absorb the deformation generated by the heating pipeline during operation. The fixed outer tube (12) includes a first fixed outer tube (121) and a second fixed outer tube (122), which are welded together. A steel-plastic connection assembly (3) is provided at the left end of the first fixed outer tube (121). The steel-plastic connection assembly (3) includes a guide sleeve (31) and a polyethylene pipe (32). The guide sleeve (31) is installed on the inner side of the left end of the fixed outer tube (12), and the polyethylene pipe (32) is installed on the outer side of the guide sleeve (31). The ring plate assembly (13) includes an inner ring plate (131) and an outer ring plate (132). The inner ring plate (131) includes a first inner ring plate (1311) and a second inner ring plate (1312). The outer ring plate (132) includes a first outer ring plate (1321) and a second outer ring plate (1322). The first inner ring plate (1311) and the second inner ring plate (1312) are disposed on the outer wall of the fixed inner tube (11). The outer ring plate (1322) is disposed on the inner wall of the fixed outer tube (12). A gap is left between the inner ring plate (131) and the fixed outer tube (12), and a gap is left between the outer ring plate (132) and the fixed inner tube (11). The inner ring plate (131) is located between the first outer ring plate (1321) and the second outer ring plate (1322). The inner ring plate (131) and the outer ring plate (132) cooperate to limit and fix the fixed inner tube (11). The corrugated pipe assembly (23) includes a corrugated pipe (231) and a first connector. The corrugated pipe (231) has a pipe (241) and a second connecting pipe (242). The left end of the corrugated pipe (231) is connected to the first end pipe (21) through the first connecting pipe (241), and the right end is connected to the second end ring plate (252) through the second connecting pipe (242). The second end ring plate (252) and the second end pipe (22) are fixed together. A clearance gap (26) is provided between the left end of the first connecting pipe (241), the first end pipe (21) and the first end ring plate (251) to absorb the deformation of the corrugated pipe assembly (23).

2. The compensation device for directly buried heating pipelines according to claim 1, characterized in that, The steel-plastic connection assembly (3) also includes a heat-expanding strip (33), which is placed on the outside of the fixed outer tube (12) and covers the interface between the polyethylene tube (32) and the fixed outer tube (12) for sealing the interface.

3. The compensation device for directly buried heating pipelines according to claim 2, characterized in that, The outer wall of the guide sleeve (31) is coated with hot melt adhesive, which is used to enhance the bonding strength between the guide sleeve (31) and the polyethylene pipe (32).

4. The compensation device for directly buried heating pipelines according to claim 1, characterized in that, A first gap is provided between the first outer ring plate (1321) and the first inner ring plate (1311), and the first gap is filled with a first heat insulation layer to isolate heat transfer between the first outer ring plate (1321) and the first inner ring plate (1311); a second gap is provided between the second outer ring plate (1322) and the second inner ring plate (1312), and the second gap is filled with a second heat insulation layer to isolate heat transfer between the second outer ring plate (1322) and the second inner ring plate (1312).

5. The compensation device for directly buried heating pipelines according to claim 1, characterized in that, A reinforcing ring plate (14) is provided between the fixed inner tube (11) and the fixed outer tube (12). The reinforcing ring plate (14) is located between the first inner ring plate (1311) and the second inner ring plate (1312). The reinforcing ring plate (14) is used to enhance the strength of the inner ring plate (131).

6. The compensation device for a directly buried heating pipeline according to claim 1, characterized in that, The outer wall of the fixed outer tube (12) is uniformly provided with a plurality of seamless tubes (15), which are used to enhance the connection between the fixed outer tube (12) and the external concrete.

7. The compensation device for a directly buried heating pipeline according to claim 1, characterized in that, The expansion joint assembly (2) also includes a limiting device (27), which is located on the right side of the second end ring plate (252) and is used to limit the bellows assembly (23). The limiting device (27) includes a limiting block (271), a third end ring plate (253) and a limiting outer tube (272). The lower end of the third end ring plate (253) is connected to the outer wall of the first end tube (21), and the upper end is connected to the limiting outer tube (272). The limiting block (271) is located on the left end of the third end ring plate (253).

8. The compensation device for a directly buried heating pipeline according to claim 1, characterized in that, The expansion joint assembly (2) also includes an outer protective sleeve (28). The left end of the outer protective sleeve (28) is connected to the first heat-insulating ring plate (41) and the second fixed outer tube (122), and the right end is connected to the second heat-insulating ring plate (42) and the second end tube (22). A sealing block (421) is provided at the lower end of the second heat-insulating ring plate (42), and the second heat-insulating ring plate (42) can slide on the outer wall of the limiting outer tube (272) through the sealing block (421).

9. The compensation device for a directly buried heating pipeline according to claim 8, characterized in that, The gaps between the polyethylene pipe (32) and the fixed inner pipe (11), the gaps between the fixed outer pipe (12) and the fixed inner pipe (11), the gaps between the outer protective sleeve (28) and the second end pipe (22), and the gaps between the limiting outer pipe (272) and the first end pipe (21) are filled with polyurethane foam.

Images