Composite heat-insulating PVC pipe

Abstract

The utility model relates to PVC pipe technical field, concretely is a kind of composite heat preservation PVC pipe, including body, the body inside material quality includes base layer, aluminium foil bubble heat preservation layer, glass wool filling heat preservation layer, rigid polyurethane foam heat preservation layer, vacuum heat insulation layer, phenolic foam heat preservation layer, interface agent layer and composite silicate heat preservation coating in proper order, the base layer one side is connected with the aluminium foil bubble heat preservation layer one side, the aluminium foil bubble heat preservation layer other side is connected with the glass wool filling heat preservation layer one side, the glass wool filling heat preservation layer other side is connected with the rigid polyurethane foam heat preservation layer one side, the rigid polyurethane foam heat preservation layer other side is connected with the vacuum heat insulation layer one side, the vacuum heat insulation layer other side is connected with the phenolic foam heat preservation layer one side, the phenolic foam heat preservation layer other side is connected with the interface agent layer one side, the utility model relates to a kind of composite heat preservation PVC pipe, solve the problem of current structure heat preservation effect is poor.

Description

Technical Field

[0001] This utility model relates to the field of PVC pipe technology, specifically to a composite heat-insulating PVC pipe. Background Technology

[0002] As is well known, PVC pipes are plastic pipes made by extruding polyvinyl chloride resin as the core raw material, with the addition of heat stabilizers, lubricants, modifiers and other additives. According to their uses, they can be divided into water supply pipes, drainage pipes, conduit pipes, agricultural irrigation pipes, etc.

[0003] In current practical applications of PVC pipes, traditional single-layer PVC pipes generally have poor insulation performance due to their high thermal conductivity (approximately 0.16-0.20 W / (m·K)) and lack of targeted insulation design. This deficiency is particularly evident when transporting hot and cold water, low-temperature media, or in environments with large outdoor temperature differences: transporting hot water will increase energy consumption due to rapid heat loss, transporting cold water is prone to condensation due to the temperature difference between the inside and outside of the pipe (which may cause moisture to get into the surrounding structure of the pipe), and outdoor use is difficult to resist the influence of ambient temperature fluctuations on the temperature of the medium inside the pipe. These problems not only limit the application range of PVC pipes in heating, cold chain, outdoor irrigation and other scenarios, but also increase maintenance costs due to frequent handling of temperature runaway, condensation and corrosion problems, ultimately significantly reducing the overall practicality and applicability of PVC pipes. Utility Model Content

[0004] (a) Technical problems to be solved

[0005] To address the shortcomings of existing technologies, this utility model provides a composite thermal insulation PVC pipe.

[0006] (II) Technical Solution

[0007] To achieve the above objectives, this utility model provides the following technical solution: a composite thermal insulation PVC pipe, comprising a body, wherein the internal materials of the body sequentially include a base layer, an aluminum foil bubble insulation layer, a glass wool filling insulation layer, a rigid polyurethane foam insulation layer, a vacuum insulation layer, a phenolic foam insulation layer, an interface agent layer, and a composite silicate insulation coating. One side of the base layer is connected to one side of the aluminum foil bubble insulation layer, the other side of the aluminum foil bubble insulation layer is connected to one side of the glass wool filling insulation layer, the other side of the glass wool filling insulation layer is connected to one side of the rigid polyurethane foam insulation layer, the other side of the rigid polyurethane foam insulation layer is connected to one side of the vacuum insulation layer, the other side of the vacuum insulation layer is connected to one side of the phenolic foam insulation layer, the other side of the phenolic foam insulation layer is connected to one side of the interface agent layer, and the other side of the interface agent layer is connected to one side of the composite silicate insulation coating.

[0008] To achieve a sealing effect, the present invention is improved by providing sealing plugs at both ends of the main body, the sealing plugs extending into the main body, and the sealing plugs matching the main body.

[0009] To improve the sealing effect, the present invention is improved by using silicone material for the sealing plug.

[0010] To improve the performance, this utility model is improved by providing an anti-corrosion and wear-resistant layer on the inner wall of the base layer, and the anti-corrosion and wear-resistant layer is fixedly connected to the inner wall of the base layer.

[0011] To improve the performance, the present invention is improved by having the composite silicate thermal insulation coating with a thickness of 20-40mm.

[0012] (III) Beneficial Effects

[0013] Compared with the prior art, this utility model provides a composite thermal insulation PVC pipe, which has the following beneficial effects:

[0014] This composite insulated PVC pipe features a series of insulation layers from the inside out: an aluminum foil bubble insulation layer, a glass wool filling insulation layer, a rigid polyurethane foam insulation layer, a vacuum insulation layer, a phenolic foam insulation layer, and a composite silicate insulation coating. Each layer works synergistically by reflecting radiant heat, blocking heat convection, and effectively isolating heat transfer. The thermal conductivity is as low as 0.015-0.045 W / (m·K), making it suitable for a wide temperature range of -196℃ to 400℃. The heat loss rate is controlled at 2%-6%, meeting the insulation needs of various scenarios such as hot and cold water transportation, low-temperature cold chain, and outdoor exposure. It also possesses fire resistance (phenolic foam reaches Class A fire resistance). With its fire-resistant and noise-reducing (glass wool sound absorption) properties, the polyurethane composite ceramic anti-corrosion and wear-resistant layer on the inner wall of the base layer can resist acid and alkali corrosion (pH 2-12) and particle erosion. The silicone sealing plugs at both ends of the main body can prevent dust and moisture from entering when not in use. The layers are tightly connected by interface agents and hot melt adhesives to prevent them from falling off or becoming damp and failing. The overall structure takes into account both construction convenience (composite silicate coating is suitable for irregular parts) and cost control (reasonable thickness range). The service life is extended to 20-25 years, effectively solving the problems of poor heat insulation, narrow application range and easy damage of traditional PVC pipes. It is suitable for use in many fields such as construction, industry and agriculture. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model;

[0016] Figure 2 This utility model Figure 1 The front view;

[0017] Figure 3 This utility model Figure 1 A schematic diagram of the internal material structure of the main body;

[0018] In the diagram: 1. Body; 2. Sealing plug; 3. Anti-corrosion and wear-resistant layer; 4. Base layer; 5. Aluminum foil bubble insulation layer; 6. Glass wool filling insulation layer; 7. Rigid polyurethane foam insulation layer; 8. Vacuum insulation layer; 9. Phenolic foam insulation layer; 10. Interface agent layer; 11. Composite silicate insulation coating. Detailed Implementation

[0019] 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.

[0020] Please see Figure 1-3 A composite thermal insulation PVC pipe includes a body 1. The internal materials of the body 1 sequentially include a base layer 4, an aluminum foil bubble insulation layer 5, a glass wool filling insulation layer 6, a rigid polyurethane foam insulation layer 7, a vacuum insulation layer 8, a phenolic foam insulation layer 9, an interface agent layer 10, and a composite silicate insulation coating 11. One side of the base layer 4 is connected to one side of the aluminum foil bubble insulation layer 5, the other side of the aluminum foil bubble insulation layer 5 is connected to one side of the glass wool filling insulation layer 6, the other side of the glass wool filling insulation layer 6 is connected to one side of the rigid polyurethane foam insulation layer 7, the other side of the rigid polyurethane foam insulation layer 7 is connected to one side of the vacuum insulation layer 8, the other side of the vacuum insulation layer 8 is connected to one side of the phenolic foam insulation layer 9, the other side of the phenolic foam insulation layer 9 is connected to one side of the interface agent layer 10, and the other side of the interface agent layer 10 is connected to one side of the composite silicate insulation coating 11.

[0021] In this embodiment, the main body 1 of the device is a commercially available conventional PVC pipe (its basic structure and molding process are existing mature technologies, which will not be elaborated here). The outer wall of the base layer 4 (i.e., the PVC pipe base) on the inner side of the main body 1 is tightly bonded with an aluminum foil bubble insulation layer 5. This insulation layer is made of aluminum foil film and polyethylene bubble film composite. The bubble is filled with still air, which is an environmentally friendly heat insulation material. The aluminum foil layer can reflect external infrared rays, greatly reducing radiative heat transfer, while the still air in the bubble can block heat convection. The overall thermal conductivity is as low as 0.035-0.045 W / ( When the aluminum foil bubble insulation layer 5 is 30mm thick, it can reduce the heat loss rate of PVC pipe by 30%-40%, while also providing waterproof and moisture-proof performance. It can prevent condensation on the inner wall of the pipe due to temperature differences, making it suitable for building hot and cold water pipes, agricultural greenhouse irrigation pipes, and other applications. The temperature resistance range covers -20℃ to 80℃. The outer side of the aluminum foil bubble insulation layer 5 is connected to the glass wool filling insulation layer 6. This layer has an annular cavity reserved around the PVC pipe body, and the cavity is filled with centrifugal glass wool (the main component is molten glass fiber, with a density of 64-80kg / m³). 3 The glass wool is wrapped with an aluminum foil fiberglass cloth moisture-proof layer (to prevent the glass wool from getting damp and affecting its insulation performance), and this moisture-proof layer is directly bonded to the subsequent insulation layer (without an additional HDPE protective layer to avoid conflict with the overall layered structure); the glass wool forms a porous structure through interwoven fibers, utilizing the low thermal conductivity of air (the thermal conductivity of air is about 0.023 W / (m·K)) to achieve efficient insulation, with an overall thermal conductivity of 0.032-0.038 W / (m·K); when the thickness of the glass wool layer is 5... At 0mm, the PVC pipe can maintain a stable insulation effect within a temperature range of -120℃ to 400℃, reducing the cold loss of low-temperature media (such as refrigerant) by more than 40%. It is suitable for cold storage water supply and drainage pipes and low-temperature fluid transportation pipes. In addition, the glass wool also has sound absorption and noise reduction properties, which can reduce the noise generated by water flow in the pipe. The outer side of the glass wool filling insulation layer 6 is connected to the rigid polyurethane foam insulation layer 7. This insulation layer is made of isocyanate and polyol through a foaming reaction, with a density of 30-50kg / m³. 3 Furthermore, the polyurethane foam has a closed-cell rate of ≥90%; the closed-cell structure effectively blocks heat conduction and convection, with an overall thermal conductivity as low as 0.022-0.028 W / (m·K); when the foam layer thickness is 35mm, the PVC pipe can maintain excellent heat insulation performance within the range of -40℃ to 100℃, with a heat loss rate of ≤4%, suitable for hot water pipes, underfloor heating connection pipes, and other scenarios. The polyurethane foam has strong adhesion to the outer structure, making it difficult to detach after bonding, and its service life can reach over 20 years. The rigid polyurethane foam insulation layer 7 is surrounded by a composite vacuum insulation layer 8, the cavity wall of which uses a 0.1-0.2mm thick metal film (such as an aluminum foil composite film), maintaining a vacuum degree of 10⁻² to 10⁻³ P within the cavity. aA vacuum environment can eliminate heat conduction and convection to the greatest extent, with only a small amount of radiative heat transfer. The overall thermal conductivity is ≤0.015W / (m·K). When the vacuum layer thickness is 20mm, PVC pipes can achieve ultimate insulation in the temperature range of -196℃ to 200℃, with a vaporization loss rate of ≤2% for low-temperature media (such as liquid nitrogen). It is suitable for high-precision temperature control pipelines in laboratories and low-temperature conveying pipelines in cold chain logistics. However, this layer is relatively expensive, and the vacuum level inside the cavity needs to be checked and maintained regularly to avoid vacuum failure affecting the insulation performance. A phenolic foam insulation layer 9 is set on the outside of the vacuum insulation layer 8. This layer is made of phenolic resin through foaming molding and has a density of 40-60kg / m³. 3 The oxygen index is ≥32%; phenolic foam has a highly cross-linked closed-cell structure with a thermal conductivity of 0.026-0.030 W / (m·K). When the thickness is 40mm, the heat loss rate of PVC pipe can be ≤6%. Phenolic foam is non-flammable, low-smoke, and non-toxic. It releases only a small amount of CO2 when exposed to fire, meeting the Class A fire resistance requirements for building materials. It is suitable for high-rise buildings, chemical industrial parks, and other scenarios with high fire resistance requirements. At the same time, it has excellent chemical corrosion resistance and can resist the erosion of acid and alkali substances in the soil. Its service life buried underground is more than 25 years. The outer side of the phenolic foam insulation layer 9 is coated with an interface agent layer 10. The main function of this layer is to enhance the adhesion between the subsequent coating and the substrate. To ensure adhesion of the layers and prevent coating peeling, the outer side of the interface agent layer 10 is a composite silicate thermal insulation coating 11. The main components of this coating are silicate fiber and inorganic binder, with a solid content of ≥80%. The thermal conductivity of the silicate fiber is 0.030-0.036 W / (m·K). After curing, the coating forms a dense thermal insulation layer, which can further block heat transfer. This coating has strong weather resistance and can withstand outdoor sun and rain environments. It is environmentally friendly and non-toxic. It can be directly applied to the surface of the pipe during construction. It is especially suitable for irregular parts such as pipe elbows and tees, and can achieve no thermal insulation blind spots in the entire pipeline. It is suitable for outdoor exposed pipes (such as roof drainage pipes and municipal open-air water supply pipes).

[0022] In this embodiment, to prevent external dust, particles, impurities, or humid air from entering the pipe and contaminating the inner wall when the main body 1 is idle (especially potentially affecting the performance of the anti-corrosion and wear-resistant layer 3 on the inner wall of the base layer 4), sealing plugs 2 are specially configured at both ends of the main body 1. The outer diameter of the sealing plug 2 is perfectly matched with the inner diameter of the main body 1 (using clearance fit, with the fit tolerance controlled within 0.05-0.1mm), ensuring that the sealing plug 2 can smoothly extend into both ends of the main body 1 and fit tightly. When the main body 1 is idle after production, transportation, or construction is suspended, the staff can push the sealing plug 2 along the axial direction of the port of the main body 1 until the sealing plug 2 completely covers the inside of the port. Through the tight fit between the sealing plug 2 and the port of the main body 1, the airflow and material exchange between the inside and outside of the pipe can be effectively blocked, which not only prevents dust particles from adhering to the inside of the pipe and affecting the purity of the medium during subsequent use, but also prevents humid air from causing the internal structure of the pipe to become damp and age, providing reliable protection for the idle storage of the main body 1.

[0023] To further enhance the sealing and protection effect of the main body 1 when it is idle and prevent external dust and humid air from seeping into the tube through the port gaps, silicone material is specially selected to make the sealing plug 2 in this embodiment. Silicone material has excellent elasticity and deformation ability. After the sealing plug 2 is inserted into the port of the main body 1, it can tightly fit the inner wall of the port through its own elastic deformation, filling any possible tiny gaps. Compared with materials such as hard plastic and rubber, its sealing fit is higher, which can significantly reduce the risk of impurities seeping in. At the same time, silicone material also has good aging resistance and temperature resistance. Even if it is idle for a long time in outdoor high temperature, low temperature or humid environment, it is not easy to harden, crack or mold. It can maintain stable sealing performance for a long time, ensuring that the internal structure of the main body 1 (such as the anti-corrosion and wear-resistant layer, and various insulation layers) is not affected by the external environment during the idle period, further extending the storage and service life of the device.

[0024] To further enhance the resistance of the inner wall of the base layer 4 to the transported media (such as sewage and fluids containing impurities) and prevent acid and alkali components in the media from corroding the pipe wall or solid particles from wearing down the inner wall, an anti-corrosion and wear-resistant layer 3 is specially added to the inner wall of the base layer 4 in this embodiment. The anti-corrosion and wear-resistant layer 3 is tightly fixed to the inner wall of the base layer 4 through a hot melt adhesive bonding process (bonding strength ≥1.5MPa, ensuring that it will not fall off during long-term use). The anti-corrosion and wear-resistant layer 3 is preferably made of polyurethane composite ceramic material. The ceramic particles (such as silicon carbide) can enhance the surface hardness (Mohs hardness ≥7) and resist the scouring and wear of particles in the fluid. The polyurethane matrix improves the flexibility and corrosion resistance of the coating and can withstand the erosion of acid and alkali media with pH 2-12. Through this structural design, the probability of damage to the inner wall of the base layer 4 due to corrosion and wear can be greatly reduced, the overall service life of the pipeline can be extended, and it is suitable for complex transportation scenarios such as industrial sewage and agricultural irrigation.

[0025] To further optimize the overall thermal insulation performance of the main body 1 and ensure that the composite silicate thermal insulation coating 11 fully exerts its thermal insulation function, while avoiding cost waste due to excessive coating thickness or the impact of insufficient thermal insulation effect due to insufficient coating thickness, the thickness of the composite silicate thermal insulation coating 11 is specifically set in a reasonable range of 20-40mm in this embodiment. This thickness range is determined by combining the thermal conductivity of the coating (0.030-0.036W / (m·K)), the heat exchange intensity of the outdoor environment, and the thermal insulation requirements of different scenarios: a thickness of 20mm can meet the basic thermal insulation requirements of general outdoor pipelines (such as drainage pipes in low-rise buildings), while a thickness of 40mm can be adapted to cold regions or high-temperature medium transportation scenarios, effectively blocking heat transfer; at the same time, at this thickness, the coating is not prone to cracking or peeling after curing, and can maintain structural stability for a long time, ensuring the continuous and reliable thermal insulation effect, while also taking into account the convenience of construction and cost control, and comprehensively improving the adaptability of pipeline use.

[0026] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A composite thermal insulation PVC pipe, comprising a body (1), characterized in that: The internal materials of the body (1) sequentially include a base layer (4), an aluminum foil bubble insulation layer (5), a glass wool filling insulation layer (6), a rigid polyurethane foam insulation layer (7), a vacuum insulation layer (8), a phenolic foam insulation layer (9), an interface agent layer (10), and a composite silicate insulation coating (11). One side of the base layer (4) is connected to one side of the aluminum foil bubble insulation layer (5), and the other side of the aluminum foil bubble insulation layer (5) is connected to one side of the glass wool filling insulation layer (6). The other side of the glass wool filling insulation layer (6) is connected to one side of the rigid polyurethane foam insulation layer (7), the other side of the rigid polyurethane foam insulation layer (7) is connected to one side of the vacuum insulation layer (8), the other side of the vacuum insulation layer (8) is connected to one side of the phenolic foam insulation layer (9), the other side of the phenolic foam insulation layer (9) is connected to one side of the interface agent layer (10), and the other side of the interface agent layer (10) is connected to one side of the composite silicate insulation coating (11).

2. The composite thermal insulation PVC pipe according to claim 1, characterized in that: The main body (1) has sealing plugs (2) at both ends, the sealing plugs (2) extend into the main body (1), and the sealing plugs (2) match the main body (1).

3. The composite thermal insulation PVC pipe according to claim 2, characterized in that: The sealing plug (2) is made of silicone.

4. The composite thermal insulation PVC pipe according to claim 3, characterized in that: The inner wall of the base layer (4) is provided with an anti-corrosion and wear-resistant layer (3), and the anti-corrosion and wear-resistant layer (3) is fixedly connected to the inner wall of the base layer (4).

5. A composite thermal insulation PVC pipe according to claim 4, characterized in that: The thickness of the composite silicate thermal insulation coating (11) is 20-40 mm.

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