Fabricated foam concrete pipeline heat preservation structure

Abstract

This utility model relates to the field of pipeline insulation technology and discloses a prefabricated foamed concrete pipeline insulation structure, comprising: at least two prefabricated pipeline sections, each prefabricated pipeline section including symmetrically spliced ​​prefabricated insulation units. The prefabricated insulation units are assembled by a stepped overlap structure, with an elastic buffer layer provided on the overlap surface. The prefabricated insulation units are composed of a foamed concrete matrix. This utility model modularizes and mass-produces foamed concrete insulation units incorporating basalt fibers, and combines this with stepped overlaps and stainless steel clamps with rubber pads for fixation. This insulation structure not only significantly reduces the thermal conductivity and improves the insulation performance, but also meets the requirements for strength and deformation. Using the prefabricated insulation structure of this utility model can reduce the pipeline frost heave and rupture caused by the freeze-thaw cycle of the soil in shallow buried pipelines, reduce engineering maintenance costs and construction time, and has significant economic and environmental benefits.

Description

Technical Field

[0001] This utility model relates to the field of pipeline insulation technology, specifically to a prefabricated foamed concrete pipeline insulation structure. Background Technology

[0002] In some large-diameter water transmission pipeline projects in cold and arid regions, shallow-buried pipelines are often used to adapt to complex mountainous terrain and reduce construction difficulty. However, this approach faces severe challenges. Shallow-buried pipelines are usually buried above the frost line. When the soil freezes and expands, the frost heave force will compress the pipeline, and the temperature difference between the top and bottom of the pipeline will cause local uplift or bending deformation, which may lead to fatigue fracture over time. When the soil thaws and settles, the soil temperature below the pipeline is high, causing the soil settlement rate to be faster than the surrounding area, forming a suspended section and exacerbating pipeline stress. At the same time, the interaction between the water temperature change inside the pipeline and the extreme low temperature outside can induce fatigue stress in the pipe wall due to thermal expansion and contraction, accelerating pipeline aging and cracking. However, existing insulation materials (such as polyurethane or ordinary foamed concrete) have low strength and poor freeze-thaw resistance, making it difficult to resist frost heave deformation and thermal stress impact, leading to pipeline leakage or structural failure, seriously threatening water transmission safety and project life.

[0003] Current pipeline insulation technologies have significant drawbacks: organic materials (such as polyurethane) are flammable and prone to aging, resulting in short lifespans under freeze-thaw cycles; cast-in-place foamed concrete has poor freeze-thaw resistance (strength loss ≥30% after 25 freeze-thaw cycles), and on-site low-temperature construction is limited; ordinary prefabricated insulation structures lack insulation measures at joints, leading to increased heat flux density and significant thermal bridging effects. Although existing patented technologies (such as CN218063967U) propose prefabricated modular designs, metal hinges are susceptible to corrosion in salt spray environments and rely on hinge bolts for shear resistance, making them prone to failure.

[0004] Therefore, in response to the special needs of shallow buried water pipelines in cold regions, there is an urgent need for a new type of pipeline insulation engineering that can effectively address heat loss and frost heave damage caused by the freeze-thaw cycle in cold and arid regions, in order to improve construction efficiency, increase overall stability, extend service life, and reduce maintenance costs. Utility Model Content

[0005] The purpose of this invention is to provide a prefabricated foamed concrete pipe insulation structure to solve the problems mentioned in the background art.

[0006] To solve the above-mentioned technical problems, this utility model provides the following technical solution: a prefabricated foamed concrete pipe insulation structure, comprising:

[0007] At least two prefabricated pipe sections, each prefabricated pipe section comprising symmetrically spliced ​​prefabricated insulation units, wherein the prefabricated insulation units are spliced ​​together by a stepped overlapping structure, and the overlapping surface is provided with an elastic buffer layer, wherein the prefabricated insulation units are composed of a foamed concrete matrix, the foamed concrete matrix comprising cement, foaming agent, basalt fiber, calcined coal gangue and silty clay.

[0008] The inner wall of the prefabricated insulation unit is sequentially covered with a graphite lubricating layer and a corrosion-resistant and wear-resistant layer, while the outer wall is sequentially covered with a fiberglass mesh reinforcement layer and a waterproof and antifreeze layer.

[0009] Stainless steel clamps are wrapped around the outside of the overlapping part of the prefabricated insulation unit, and heat-insulating rubber gaskets are provided between the clamps and the prefabricated insulation unit.

[0010] Stainless steel flexible locking straps are embedded in the reserved grooves on the outer wall of the prefabricated insulation unit through nylon thermal insulation sleeve bolts, and are used to connect adjacent prefabricated pipe sections.

[0011] The joints between adjacent prefabricated pipe sections are filled with nano-aerogel felt and covered with HDPE waterproof membrane.

[0012] According to the above technical solution, the friction coefficient of the graphite lubricating layer is ≤0.1, and the allowable axial sliding displacement of the pipeline is ≤5mm;

[0013] The corrosion-resistant and wear-resistant layer is an epoxy resin coating or a polyurethane elastomer layer with a thickness of 0.1-0.5 mm;

[0014] The fiberglass mesh reinforcement layer has a mesh density of 4-8 meshes / inch;

[0015] The waterproof and antifreeze layer is an HDPE membrane or a sprayed polyurea layer, with the HDPE membrane having a thickness of 1.0-1.5 mm.

[0016] According to the above technical solution, the stainless steel clamp surface is coated with a ceramic coating, the coating composition of which includes 60-70wt% Al2O3 and 20-30wt% SiO2, with a thickness of 30-80μm.

[0017] According to the above technical solution, the step height of the stepped overlapping structure is 10-25mm, the overlap length is ≥50mm, and the step inclination angle is 30°-45°.

[0018] According to the above technical solution, the stainless steel flexible buckle band has a width of 80-100mm, a thickness of 1.5-2.0mm, and a ceramic coating on its surface. The coating composition includes 60-70wt% Al2O3 and 20-30wt% SiO2, with a thickness of 30-80μm.

[0019] According to the above technical solution, the elastic buffer layer is a closed-cell rubber or silicone rubber gasket.

[0020] A method for preparing a prefabricated foamed concrete pipe insulation structure includes the following steps:

[0021] S1, Preparation of prefabricated insulation unit

[0022] S11, Raw material ratio: Mix 20-30 parts of calcined coal gangue, 10-20 parts of silty clay, 0.5-2.5 parts of basalt fiber with 50-55 parts of cement, add 3-6 parts of high-molecular composite cement foaming agent, and the water-cement ratio is 0.4-0.55.

[0023] S12, Mixed foaming: Dry mix for 3 minutes, add water and wet mix for 5 minutes, then inject into the foaming machine to generate foamed concrete slurry;

[0024] S13, Mold forming: Pour the slurry into a steel mold with a pre-formed anti-corrosion layer on the inner wall and compact it by vibration;

[0025] S14, Steam curing: Curing for 28 days under constant temperature and relative humidity >95% to form a prefabricated insulation unit with an oven-dry density of 750-850 kg / m³ and a compressive strength ≥2.0MPa;

[0026] S2, Stepped mortise and tenon joint structure processing

[0027] S21, Mortise and tenon forming: Stepped mortise and tenon joints are processed at both ends of the prefabricated insulation unit, with a step height of 10-25mm, an inclination angle of 30°-45°, and an overlap length of ≥50mm.

[0028] S22, Buffer layer installation: A closed-cell rubber or silicone rubber pad is embedded in the tenon-and-mortise contact surface to absorb the energy of frost heave displacement and block the transfer of thermal bridges.

[0029] S23, Locking groove reserved: A locking strip installation groove with a width of 85mm and a depth of 10mm is milled along the outer wall of the prefabricated insulation unit;

[0030] S3, Stainless Steel Flexible Locking System Assembly

[0031] S31, Locking strap fixing: Embed the stainless steel flexible locking strap into the reserved groove. The stainless steel locking strap is 1.5-2.0mm thick and 80-100mm wide. Insert the nylon heat-insulating sleeve bolt.

[0032] S32, Preload control: Apply torque of 18 N·m, allow axial displacement of ±5 mm, and compensate for thermal expansion and contraction of the pipeline through a flexible locking system;

[0033] S4, Joint thermal bridging and sealing

[0034] S41, Aerogel Filling: Nano-aerogel felt is filled at the joint between adjacent units to block heat transfer;

[0035] S42, HDPE membrane covering: using 1.0-1.5mm thick HDPE waterproof membrane hot-melt welding;

[0036] S43, External wall coating: The entire pipe is coated with polyurea elastomer with a thickness of 2.5mm to enhance waterproof and antifreeze performance.

[0037] According to the above technical solution, in step S3, after the stainless steel flexible buckle is installed, it is subjected to surface treatment by spraying an Al2O3-SiO2 ceramic coating with a thickness of 30-80μm to improve corrosion resistance.

[0038] According to the above technical solution, in step S41, the thickness of the nano-aerogel felt is 10-20 mm, and the thermal conductivity is ≤0.018 W / (m·K).

[0039] According to the above technical solution, in step S42, the HDPE waterproof membrane is welded at a temperature of 200°C, covering the seam with a weld width of 25mm to prevent moisture intrusion.

[0040] Compared with the prior art, the beneficial effects achieved by this utility model are:

[0041] (1) Improve thermal insulation performance: Foamed concrete has low density, high porosity and good thermal insulation performance, which can reduce the damage to pipelines caused by the freeze-thaw cycle of the soil.

[0042] (2) Enhanced mechanical properties: The addition of basalt fiber can effectively improve the ability of foamed concrete to resist freeze-thaw cycles and enhance its overall durability and stability.

[0043] (3) Strong structural stability: The stepped tenon structure can resist frost heave shear force, and the stainless steel buckle allows ±5mm axial displacement, providing flexible displacement compensation and reserving space for thermal expansion and contraction of the insulation unit.

[0044] (4) Save material costs: Use industrial waste calcined coal gangue to replace more than 30% of cement as filler, reduce the consumption of traditional materials, reduce project costs, and improve resource utilization, which meets the requirements of green building materials.

[0045] (5) Efficient and convenient construction: The factory prefabricated units, combined with mechanical hoisting, greatly reduce the construction period and lower construction costs compared with ordinary foam concrete or deep-buried pipeline solutions.

[0046] (6) Adaptable to cold regions: Specifically designed for shallow buried pipeline projects in cold regions, it takes into account multiple functions such as heat preservation and waterproofing, and improves the durability of water transmission projects. Attached Figure Description

[0047] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0048] Figure 1 This is a three-dimensional schematic diagram of the present invention;

[0049] Figure 2 This is a cross-sectional schematic diagram of the prefabricated insulation unit of this utility model;

[0050] Figure 3 This is a side view of the present invention;

[0051] Figure 4 This is a schematic flowchart of the preparation method of this utility model;

[0052] In the diagram: 1-Prefabricated insulation unit, 101-Foamed concrete substrate, 102-Graphite lubricating layer, 103-Anti-corrosion and wear-resistant layer, 104-Fiberglass mesh reinforcement layer, 105-Waterproof and antifreeze layer, 2-Stepped overlapping structure, 3-Elastic buffer layer, 4-Stainless steel clamp, 5-Heat insulation rubber gasket, 6-Stainless steel flexible locking strap, 7-Nano aerogel felt, 8-HDPE waterproof membrane. Detailed Implementation

[0053] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0054] Please see Figure 1-4 This utility model provides a technical solution: a prefabricated foamed concrete pipe insulation structure, comprising:

[0055] At least two prefabricated pipe sections, each prefabricated pipe section comprising symmetrically spliced ​​prefabricated insulation units 1, wherein the prefabricated insulation units 1 are spliced ​​together by a stepped overlapping structure 2, and the overlapping surface is provided with an elastic buffer layer 3, wherein the prefabricated insulation unit 1 is composed of a foamed concrete matrix 101, wherein the foamed concrete matrix 101 comprises cement, foaming agent, basalt fiber, calcined coal gangue and silty clay;

[0056] The inner wall of the prefabricated insulation unit 1 is sequentially covered with a graphite lubricating layer 102 and an anti-corrosion and wear-resistant layer 103, and the outer wall is sequentially covered with a fiberglass mesh reinforcement layer 104 and a waterproof and antifreeze layer 105.

[0057] Stainless steel clamp 4 is wrapped around the outside of the overlapping part of the prefabricated insulation unit 1, and a heat-insulating rubber gasket 5 is provided between it and the prefabricated insulation unit 1.

[0058] The stainless steel flexible locking strap 6 is embedded in the reserved groove on the outer wall of the prefabricated insulation unit 1 through the nylon heat-insulating sleeve bolt, and is used to connect adjacent prefabricated pipe sections.

[0059] The joints of adjacent prefabricated pipe sections are filled with nano-aerogel felt 7 and covered with HDPE waterproof membrane 8;

[0060] Specifically, the graphite lubricating layer 102 has a friction coefficient ≤0.1 and allows for axial sliding displacement of the pipe ≤5mm;

[0061] The corrosion-resistant and wear-resistant layer 103 is an epoxy resin coating or a polyurethane elastomer layer with a thickness of 0.1-0.5 mm.

[0062] The fiberglass mesh reinforcement layer has a mesh density of 4-8 meshes / inch;

[0063] The waterproof and antifreeze layer 105 is an HDPE film or a sprayed polyurea layer, and the thickness of the HDPE film is 1.0-1.5mm;

[0064] Specifically, the stainless steel clamp 4 is coated with a ceramic coating, the coating composition of which includes 60-70wt% Al2O3 and 20-30wt% SiO2, with a thickness of 30-80μm.

[0065] Specifically, the stepped overlap structure 2 has a step height of 10-25mm, an overlap length of ≥50mm, and a step inclination angle of 30°-45°.

[0066] Specifically, the stainless steel flexible buckle band 6 has a width of 80-100mm, a thickness of 1.5-2.0mm, and a ceramic coating on its surface. The coating composition includes 60-70wt% Al2O3 and 20-30wt% SiO2, with a thickness of 30-80μm.

[0067] Specifically, the elastic buffer layer 3 is a closed-cell rubber or silicone rubber gasket;

[0068] A method for preparing a prefabricated foamed concrete pipe insulation structure includes the following steps:

[0069] S1, Preparation of prefabricated insulation unit 1

[0070] S11, Raw material ratio: Mix 20-30 parts of calcined coal gangue, 10-20 parts of silty clay, 0.5-2.5 parts of basalt fiber with 50-55 parts of cement, add 3-6 parts of high-molecular composite cement foaming agent, and the water-cement ratio is 0.4-0.55.

[0071] S12, Mixed foaming: Dry mix for 3 minutes, add water and wet mix for 5 minutes, then inject into the foaming machine to generate foamed concrete slurry;

[0072] S13, Mold forming: Pour the slurry into a steel mold with a pre-formed anti-corrosion layer on the inner wall and compact it by vibration;

[0073] S14, Steam curing: Curing for 28 days under constant temperature and relative humidity > 95% to form a prefabricated insulation unit 1 with an oven-dry density of 750-850 kg / m³ and a compressive strength ≥ 2.0 MPa;

[0074] S2, Stepped mortise and tenon joint structure processing

[0075] S21, Mortise and tenon forming: Stepped mortise and tenon joints are processed at both ends of the prefabricated insulation unit 1, with a step height of 10-25mm, an inclination angle of 30°-45°, and an overlap length of ≥50mm.

[0076] S22, Buffer layer installation: A closed-cell rubber or silicone rubber pad is embedded in the tenon-and-mortise contact surface to absorb the energy of frost heave displacement and block the transfer of thermal bridges.

[0077] S23, Locking groove reserved: A locking strip installation groove with a width of 85mm and a depth of 10mm is milled along the outer wall of the prefabricated insulation unit 1;

[0078] S3, Stainless Steel Flexible Locking System Assembly

[0079] S31, Locking strap fixing: Embed the stainless steel flexible locking strap 6 into the reserved groove. The stainless steel locking strap is 1.5-2.0mm thick and 80-100mm wide. Insert the nylon heat-insulating sleeve bolt.

[0080] S32, Preload control: Apply torque of 18 N·m, allow axial displacement of ±5 mm, and compensate for thermal expansion and contraction of the pipeline through a flexible locking system;

[0081] S4, Joint thermal bridging and sealing

[0082] S41, Aerogel filling: Nano aerogel felt 7 is filled at the joint between adjacent units to block heat transfer;

[0083] S42, HDPE membrane covering: using 1.0-1.5mm thick HDPE waterproof membrane 8 hot melt welding;

[0084] S43, External wall coating: The entire pipe is coated with polyurea elastomer with a thickness of 2.5mm to enhance waterproof and antifreeze performance;

[0085] Specifically, in step S3, after the stainless steel flexible buckle 6 is installed, it is surface treated by spraying an Al2O3-SiO2 ceramic coating with a thickness of 30-80μm to improve corrosion resistance.

[0086] Specifically, in step S41, the nano-aerogel felt 7 has a thickness of 10-20 mm and a thermal conductivity of ≤0.018 W / (m·K);

[0087] Specifically, in step S42, the HDPE waterproof membrane 8 is welded at a temperature of 200°C, covering the seam with a weld width of 25mm to prevent moisture intrusion.

[0088] This utility model is particularly suitable for pipeline construction in cold regions. Through reasonable selection of insulation materials and joint design, it provides an efficient solution that balances pipeline insulation and strength. It makes full use of industrial solid waste and inexpensive silty clay to replace cement, which is both environmentally friendly and reduces costs. By adopting prefabricated insulation units and modular assembly of the insulation layer, it effectively reduces construction difficulty and later maintenance costs. The prefabricated foamed concrete insulation composite structure of this utility model includes the following components:

[0089] Prefabricated insulation unit 1: The core insulation is a foamed concrete matrix made of cement, calcined coal gangue, silty clay, basalt fiber and foaming agent. It uses low-density and low thermal conductivity materials to achieve efficient heat insulation, and has a 28-day compressive strength ≥2.0Mpa, which can fully resist the pressure of frost heave soil and achieve the function of compressive support. Coal gangue is used to replace 30% of cement to dispose of industrial solid waste and achieve the purpose of carbon reduction.

[0090] Stepped overlapping structure 2: It consists of a stepped tenon structure processed at the end of the unit, with a closed-cell rubber buffer layer 3 embedded in it. It resists the lateral shear force caused by frost heave through mechanical interlocking. The rubber layer is used to absorb the energy of frost heave displacement and block the transmission of heat bridge.

[0091] Stainless steel flexible locking strap 6 and flexible locking system: The stainless steel flexible locking strap 6 covering the overlapping part is combined with the axial flexible locking strap and nylon thermal insulation sleeve; the clamp is used to provide radial restraint force on the pipeline to prevent the unit from falling off; the flexible locking strap provides displacement compensation (±5mm) for the insulation unit, allowing the pipeline to expand and contract with thermal expansion and contraction.

[0092] The seam thermal bridging system consists of a nano-aerogel felt 7 and an HDPE waterproof membrane 8. The aerogel is used to fill the seams and block heat flow; the HDPE membrane is heat-fused to prevent moisture intrusion and frost heave.

[0093] The inner and outer wall composite protective layer consists of a graphite lubricating layer 102, an anti-corrosion and wear-resistant layer 103, a fiberglass mesh reinforcement layer 104, and a waterproof and antifreeze layer 105. The inner wall anti-corrosion and wear-resistant layer 103 is made of epoxy resin to reduce the friction coefficient of the pipeline and prevent corrosion of the water pipe wall. The outer wall waterproof and antifreeze layer 105 is made of sprayed polyurea or HDPE film to block the penetration of external water vapor. The fiberglass mesh reinforcement layer 104 is made of 4-8 mesh / inch fiberglass mesh to inhibit the freezing and cracking of the outer wall and improve the overall tensile strength.

[0094] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0095] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A fabricated foam concrete pipe thermal insulation structure, characterized in that, include: At least two prefabricated pipe sections, each prefabricated pipe section comprising symmetrically spliced ​​prefabricated insulation units (1), the prefabricated insulation units (1) being spliced ​​together by a stepped overlap structure (2), the overlap surface being provided with an elastic buffer layer (3), the prefabricated insulation units (1) being composed of a foamed concrete matrix (101); The inner wall of the prefabricated insulation unit (1) is sequentially covered with a graphite lubricating layer (102) and an anti-corrosion and wear-resistant layer (103), and the outer wall is sequentially covered with a fiberglass mesh reinforcement layer (104) and a waterproof and antifreeze layer (105). Stainless steel clamps (4) are wrapped around the outside of the overlapping part of the prefabricated insulation unit (1), and heat-insulating rubber gaskets (5) are provided between them and the prefabricated insulation unit (1). Stainless steel flexible buckle strap (6) is embedded in the reserved groove on the outer wall of the prefabricated insulation unit (1) by nylon heat insulation sleeve bolts, and is used to connect adjacent assembled pipe sections; The joints of adjacent prefabricated pipe sections are filled with nano-aerogel felt (7) and covered with HDPE waterproof membrane (8).

2. The prefabricated foam concrete pipe thermal insulation structure according to claim 1, characterized in that: The graphite lubricating layer (102) has a friction coefficient ≤0.1 and allows axial sliding displacement of the pipeline ≤5mm; The corrosion-resistant and wear-resistant layer (103) is an epoxy resin coating or a polyurethane elastomer layer with a thickness of 0.1-0.5 mm; The fiberglass mesh reinforcement layer (104) has a mesh density of 4-8 meshes / inch; The waterproof and antifreeze layer (105) is an HDPE film or a sprayed polyurea layer, and the thickness of the HDPE film is 1.0-1.5mm.

3. The prefabricated foam concrete pipe thermal insulation structure according to claim 1, characterized in that: The stainless steel clamp (4) is coated with a ceramic coating with a thickness of 30-80μm.

4. The prefabricated foam concrete pipe thermal insulation structure according to claim 1, characterized in that: The stepped lap structure (2) has a step height of 10-25mm, an lap length of ≥50mm, and a step angle of 30°-45°.

5. The prefabricated foam concrete pipe thermal insulation structure according to claim 1, characterized in that: The stainless steel flexible buckle band (6) has a width of 80-100mm, a thickness of 1.5-2.0mm, and a ceramic coating with a thickness of 30-80μm.

6. The prefabricated foam concrete pipe thermal insulation structure according to claim 1, characterized in that: The elastic buffer layer (3) is a closed-cell rubber or silicone rubber gasket.

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