High temperature heat supply pipeline thermal insulation coating

Abstract

The present application relates to a kind of high temperature heat supply pipeline insulation coating, it includes high temperature resistant layer, transition buffer layer and waterproof function layer sequentially arranged in the surface of pipeline from inside to outside;Wherein, the high temperature resistant layer is uniformly coated by the high temperature resistant aerogel insulation coating with dry film thickness of 2~4mm, the transition buffer layer is uniformly coated by the normal temperature aerogel insulation coating with dry film thickness of 3~5mm, the waterproof function layer is uniformly coated by the polymer cement waterproof coating with dry film thickness of 0.1~0.3mm.The present application can be firmly attached to the surface of high temperature heat supply pipeline and its valve etc metal matrix by unique gradient composite structure design, significantly improve its long-term insulation performance and protection reliability under high temperature, high humidity and cold and hot cycle conditions, while having excellent construction adaptability.

Description

Technical Field

[0001] This invention relates to the technical field of thermal insulation coatings, and in particular to a thermal insulation coating for high-temperature heating pipelines. Background Technology

[0002] In urban centralized heating and industrial steam transmission systems, high-temperature heating pipelines and their associated valves and other components are critical infrastructure for ensuring efficient heat transfer. To reduce heat loss during the transport of high-temperature media (such as superheated steam and hot water), improve energy efficiency, and prevent operational safety hazards and equipment corrosion caused by excessive surface temperature or condensate erosion, applying an efficient and durable insulation layer to the outer surface of the pipeline is an essential engineering measure. Traditional insulation technologies mainly rely on inorganic porous fiber materials such as rock wool, glass wool, and aluminum silicate fiber. A certain thickness of insulation layer is formed on the outside of the pipeline through processes such as cutting, wrapping, and binding, and is often supplemented with a metal or non-metal protective shell. These materials have low thermal conductivity at room temperature. However, when subjected to prolonged high-temperature environments above 150 degrees Celsius, especially under complex conditions involving humidity fluctuations and thermal cycling, their performance limitations become apparent. On the one hand, the thermal conductivity of the material increases significantly with increasing temperature, leading to a decrease in insulation efficiency. On the other hand, the fiber material easily absorbs moisture from the environment, and its thermal conductivity deteriorates drastically after becoming damp. This not only results in the loss of insulation but also exacerbates the electrochemical corrosion of the pipeline due to the continuous evaporation and condensation of the absorbed moisture on the surface of the high-temperature pipe. Furthermore, traditional wrapping insulation is difficult to apply to irregularly shaped structures such as elbows and valves, easily creating gaps that form thermal bridges, leading to severe localized heat loss. Additionally, the construction process is cumbersome and poorly adaptable to installation scenarios with limited space.

[0003] With the development of nanomaterials technology, aerogel insulation coatings have attracted widespread attention as a novel nanoporous thermal insulation coating material. The basic principle involves dispersing nanoscale silica aerogel particles in an organic or inorganic binder system, forming a continuous coating with extremely low bulk density and nanoscale pores on the substrate surface through spraying or other methods. Thanks to its unique nanoporous structure, this type of coating exhibits excellent thermal insulation performance under laboratory conditions. However, existing aerogel insulation coatings still face a series of technical bottlenecks when applied to practical engineering projects involving high-temperature pipelines. First, to achieve sufficient thermal resistance, a considerable coating thickness is required, but a single aerogel coating system is unlikely to form an excessively thick coating in a single application; otherwise, internal stress can easily lead to cracking or peeling, making its overall thermal resistance often inferior to traditional thick-layer coating materials. Second, coatings that come into direct contact with high-temperature metal pipelines need to withstand long-term high temperatures. Some existing aerogel coatings experience a significant decrease in adhesion strength to the metal substrate at high temperatures, posing a risk of peeling. Furthermore, unavoidable temperature fluctuations during pipeline operation generate thermal stress, and single-layer materials are insufficient in resisting thermal shock fatigue. More importantly, existing technologies mostly focus on improving the thermal insulation performance of the coating itself, lacking a synergistic and systematic design for comprehensive performance such as efficient thermal insulation, stress buffering, and long-term waterproofing and moisture-proofing. Most products are single-coat structures, or simply stack different functional coatings without fully considering interlayer compatibility and stress matching. Under harsh environments of high temperature, high humidity, and thermal cycling, problems such as interlayer separation, cracking, and waterproofing failure are prone to occur, resulting in insufficient overall reliability and durability of protection.

[0004] Therefore, there is an urgent need in this field for an innovative coating system and construction method that can overcome the inherent defects of traditional insulation materials and existing aerogel coatings. The ideal solution should be able to directly form a strongly adhered, sufficiently thick insulation layer on the irregular surface of the pipeline. Simultaneously, the system should possess excellent long-term high-temperature stability, outstanding thermal shock fatigue resistance, and reliable environmental moisture barrier capabilities, thus providing a convenient, high-performance, and durable integrated protection method for high-temperature heating pipelines. Summary of the Invention

[0005] The problem to be solved by the present invention is to provide a high-temperature heating pipeline insulation coating that addresses the above-mentioned shortcomings of the prior art. Through a unique gradient composite structure design, it can firmly adhere to the surface of the metal substrate such as the high-temperature heating pipeline and its valves, significantly improving its long-term insulation performance and protective reliability under high temperature, high humidity and hot and cold cycle conditions, while also having excellent construction adaptability.

[0006] The above-mentioned objective of this invention is achieved through the following technical solutions: A high-temperature heating pipeline insulation coating includes a high-temperature resistant layer, a transition buffer layer, and a waterproof functional layer sequentially disposed on the pipeline surface from the inside out; wherein, the high-temperature resistant layer is uniformly coated with a high-temperature resistant aerogel insulation coating with a dry film thickness of 2-4 mm, the transition buffer layer is uniformly coated with a room-temperature aerogel insulation coating with a dry film thickness of 3-5 mm, and the waterproof functional layer is uniformly coated with a polymer cement waterproof coating with a dry film thickness of 0.1-0.3 mm.

[0007] Furthermore, the high-temperature resistant aerogel insulation coating is composed of the following raw materials in parts by weight: 35-50 parts of perhydropolysilazane, 20-30 parts of silica aerogel nanoparticles, 5-15 parts of zirconium oxide nanoparticles, 15-25 parts of butyl acetate, and 1-3 parts of dispersant.

[0008] Furthermore, the dispersant is γ-glycidoxypropyltrimethoxysilane.

[0009] Furthermore, the high-temperature resistant layer is obtained by uniformly spraying a high-temperature resistant aerogel insulation coating onto the pipe surface at a pressure of 0.4~0.8MPa, heating it to above 200℃ at a heating rate of 3~5℃ / min, curing it at a high temperature, holding it at that temperature for 1 hour, and then cooling it. After curing, the thermal conductivity is ≤0.035W / (m·K), the operating temperature range is -30~600℃, and the bonding strength with the pipe is ≥0.6MPa at 300℃.

[0010] After curing at temperatures above 200℃, the high-temperature resistant aerogel insulation coating transforms from perhydropolysilazane (PHPS) as a precursor into a silica ceramic phase. This phase, together with silica aerogel nanoparticles, forms a low thermal conductivity framework. Zirconia nanoparticles are then added to adjust the thermal expansion coefficient of the high-temperature resistant layer and to match it with the metal substrate of the pipe, thereby reducing interfacial thermal stress and enhancing the high-temperature structural stability of the coating. Silica aerogel nanoparticles, with their nanoscale porous structure, effectively suppress air convection heat transfer and solid-state heat conduction, making them the core component for achieving low thermal conductivity. The introduction of zirconia nanoparticles not only enhances the overall heat resistance of the high-temperature resistant layer by utilizing their high melting point but also optimizes the dimensional stability of the coating during temperature changes through the complementary difference in thermal expansion coefficients between them and silica aerogel, reducing internal stress caused by thermal expansion and contraction. KH-560 silane coupling agent reacts with the hydroxyl groups on the surface of inorganic particles through the siloxane groups in its molecular structure, while the organic functional groups at the other end are compatible with the polymer segments of the perhydropolysilazane. This significantly improves the interfacial bonding between the components, increases the density and mechanical strength of the high-temperature resistant layer, and ensures that it is not prone to cracking or peeling under high-temperature service conditions.

[0011] Furthermore, the room temperature aerogel insulation coating is composed of the following raw materials in parts by weight: 25-40 parts silica aerogel nanoparticles, 40-55 parts elastic emulsion, 10-20 parts glass microspheres, 0.1-0.3 parts isothiazolinone bactericide, and 5-8 parts filler additives.

[0012] Furthermore, the solid content of the elastic emulsion is ≥50%.

[0013] Furthermore, the transition buffer layer is formed by uniformly spraying a room-temperature aerogel insulation coating onto the surface of the high-temperature resistant layer at a pressure of 0.4~0.8MPa, then heating it to a high temperature above 200℃ at a heating rate of 3~5℃ / min and curing it. After curing, it is surface-dried at an environment of ≥5℃ for 5~7 hours. The thermal conductivity after curing is ≤0.036W / (m·K), and the long-term service temperature is below 100℃.

[0014] Room-temperature aerogel insulation coating not only retains the low thermal conductivity of the high-temperature resistant layer, but its room-temperature application significantly reduces on-site construction difficulty and environmental requirements, allowing for convenient coating application without high-temperature pretreatment. The elastic emulsion, acting as a film-forming substance, forms a continuous phase with a certain degree of flexibility during curing, endowing the transition buffer layer with good elasticity and ductility. This allows it to better adapt to the minor deformations of the pipeline caused by temperature changes or external forces during operation, further alleviating interfacial thermal stress. The addition of glass microspheres, utilizing their hollow structure, further reduces the overall density of the coating while improving its thermal insulation and reflective properties. Working synergistically with silica aerogel nanoparticles, they jointly construct a highly efficient thermal insulation barrier. The isothiazolinone bactericide effectively inhibits microbial growth during storage and use, ensuring the stability of the coating's performance and its service life. Fillers and additives play a role in the system by dispersing, thickening, and defoaming, optimizing the coating’s workability and storage stability, ensuring that the transition buffer layer can be uniformly and stably coated on the surface of the high-temperature resistant layer, forming a structurally complete and reliable insulation transition interface, thereby working together with the high-temperature resistant layer to significantly improve the overall insulation effect and service life of the high-temperature heating pipeline.

[0015] Furthermore, the polymer cement waterproof coating is composed of the following raw materials in parts by weight: 50 parts of acrylic emulsion, 50-75 parts of ordinary silicate cement, and 0.25-7.50 parts of additives.

[0016] Furthermore, the solid content of the acrylate emulsion is ≥50%.

[0017] Furthermore, the waterproof functional layer is prepared by uniformly spinning a polymer cement waterproof coating on the surface of the transition buffer layer at 800~1200 rpm at least twice, controlling the time interval between each spin coating to be 20~40 min, and curing at room temperature; after curing, the tensile strength is ≥1.8MPa, the elongation at break is ≥200%, the bond strength is ≥0.6MPa, and the water vapor transmission rate is ≤0.15g / (㎡·h).

[0018] The molecular structure of polymer cement waterproof coatings contains both flexible segments of acrylic polymers and rigid components of hydraulic materials in ordinary silicate cement, forming an interpenetrating network structure during curing. This structure gives the waterproof layer excellent flexibility, allowing it to adapt to the deformation of pipelines during thermal expansion and contraction, effectively preventing cracking; at the same time, it also possesses high rigidity and hardness, resisting mechanical damage from the external environment. The high solids content of the acrylic emulsion ensures the integrity and density of the film formation, and synergistically with silicate cement, significantly improves the adhesion strength of the coating, enabling it to adhere tightly to the surface of the transition buffer layer and prevent the penetration of corrosive media such as moisture and humidity. The addition of additives further optimizes the coating's application performance and overall performance after curing, such as improving leveling, regulating curing speed, and enhancing anti-aging capabilities, thus enabling the waterproof layer to perform its waterproof function stably for a long time, ensuring the overall safety and durability of the high-temperature heating pipeline insulation system.

[0019] In summary, the beneficial technical effects of the present invention are as follows: 1. This invention employs a gradient sandwich structure consisting of a high-temperature resistant layer, a transition buffer layer, and a waterproof functional layer. The high-temperature resistant layer directly faces the high temperature of the pipeline, effectively blocking heat transfer due to its low thermal conductivity (≤0.035W / (m·K)). The transition buffer layer uses a more elastic room-temperature aerogel coating, which can effectively absorb and buffer thermal stress caused by temperature differences, enhancing the thermal shock resistance and overall stability of the coating system. The waterproof functional layer provides a dense and highly efficient waterproof barrier and environmental corrosion resistance. The synergistic effect of these three layers solves the problem of delamination and failure caused by interface mismatch in traditional multi-layered heterogeneous materials. 2. This invention achieves uniform and dense coating of complex irregular structures (such as valves and elbows) through the coordinated design of material systems and construction processes, making construction convenient and efficient. The combination of spraying and spin coating processes, along with real-time thickness monitoring, ensures consistent coating quality and improves construction efficiency. 3. The coating system of this invention exhibits excellent overall performance. Testing shows that it has a low overall thermal conductivity and demonstrates superior energy-saving performance compared to traditional thick-layer insulation solutions in a 250℃ steam insulation test, reducing heat loss by more than 40%. Simultaneously, the system passed 500 thermal shock cycles at temperatures ranging from ~30℃ to 200℃ and possesses excellent hydrophobicity (contact angle approximately 112°) and resistance to damp heat aging (no abnormalities observed at 60℃, 90%RH, for 168 hours). This achieves a balance between high-efficiency insulation, long-lasting waterproofing, and structural stability, making it suitable for the protection of various high-temperature hydrophobic systems. Detailed Implementation

[0020] To make the technical means, creative features, objectives and effects of this invention clearer and easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0021] Example 1: A high-temperature heating pipeline insulation coating disclosed in this invention includes a high-temperature resistant layer, a transition buffer layer, and a waterproof functional layer sequentially disposed on the pipeline surface from the inside out. Wherein, The high-temperature resistant layer is uniformly coated with a high-temperature resistant aerogel insulation coating with a dry film thickness of 3mm. The high-temperature resistant aerogel insulation coating is composed of the following raw materials in parts by weight: 45 parts of perhydropolysilazane, 25 parts of silica aerogel nanoparticles, 10 parts of zirconium oxide nanoparticles, 18 parts of butyl acetate, and 2 parts of γ-glycidyl etheroxypropyltrimethoxysilane. The transition buffer layer is uniformly coated with a room-temperature aerogel insulation coating with a dry film thickness of 4mm. The room-temperature aerogel insulation coating is composed of the following raw materials in parts by weight: 35 parts silica aerogel nanoparticles, 48 ​​parts elastic emulsion with a solid content of 52%, 12 parts glass microspheres, 0.2 parts isothiazolinone bactericide (Shandong Aicino Environmental Protection Technology Co., Ltd. BC-105), and 4.8 parts filler additive (Germany BYK Chemical Co., Ltd. BYK-349). The waterproof functional layer is uniformly coated with a polymer cement waterproof coating with a dry film thickness of 0.2mm; the polymer cement waterproof coating is composed of the following raw materials in parts by weight: 50 parts of acrylic emulsion (Suzhou Xuming Cibo Chemical New Material Co., Ltd. 0757) with a solid content ≥50%, 60 parts of ordinary silicate cement, and 4.8 parts of additive (Changwei Co., Ltd. CW-687HV).

[0022] The specific implementation method of the above-mentioned thermal insulation coating is as follows: S1. Hydrogen-containing polysilazane, silica aerogel nanoparticles and zirconium oxide nanoparticles were sequentially added to butyl acetate, and then γ-glycidyl etheroxypropyltrimethoxysilane was added. The mixture was ground in a planetary ball mill for 1 hour and then stirred in a mechanical stirrer for 1 hour. After that, it was filtered and packaged to obtain a high-temperature resistant aerogel insulation coating. S2 sequentially adds silica aerogel nanoparticles, elastic emulsion and glass microspheres into filler additives, then adds isothiazolinone bactericide, grinds the mixture in a planetary ball mill for 1 hour, stirs it with a mechanical stirrer for 1 hour, and then filters and encapsulates it to obtain room temperature aerogel thermal insulation coating. S3 mixes acrylic emulsion, ordinary silicate cement, and additives using a mechanical mixer for 0.5 hours to obtain a polymer cement waterproof coating. S4 pre-treats the surface of the pipe with 20G carbon steel substrate by sandblasting, achieving a cleanliness level of Sa2.5 and a surface roughness Ra of 35μm; S5 uses a real stone paint spray gun (4mm nozzle, 0.6MPa spraying pressure) to spray the high-temperature resistant aerogel insulation coating obtained in S1 onto the pipe surface obtained in S4. The dry film thickness is controlled to be 3mm by an infrared thickness gauge. The sprayed workpiece is placed in a heating furnace and heated to 200℃ at a heating rate of 3℃ / min for high-temperature curing. After holding at the temperature for 1 hour, it is cooled to room temperature with the furnace to obtain a high-temperature resistant layer. S6 uses the same process parameters as S5 to spray the high-temperature resistant layer obtained by S5 with the room temperature aerogel insulation coating prepared by S2, controls the dry film thickness to be 4mm, and surface dries for 6h under an ambient temperature not lower than 5℃ to obtain a transition buffer layer. S7 coats the surface of the transition buffer layer obtained in S6 with the polymer cement waterproof coating prepared in S3. The coating is applied evenly twice using a spin coating process (1000 rpm), with a 30-minute interval between each coat. The total dry film thickness is controlled to be 0.2 mm. The coating is then cured at room temperature to obtain a waterproof functional layer.

[0023] Example 2: This invention discloses a high-temperature heating pipeline insulation coating. The difference from Example 1 is that the high-temperature resistant layer is uniformly coated with a high-temperature resistant aerogel insulation coating with a dry film thickness of 2 mm. The high-temperature resistant aerogel insulation coating is composed of the following raw materials in parts by weight: 35 parts of perhydropolysilazane, 20 parts of silica aerogel nanoparticles, 5 parts of zirconium oxide nanoparticles, 15 parts of butyl acetate, and 1 part of γ-glycidyl etheroxypropyltrimethoxysilane.

[0024] Example 3: This invention discloses a high-temperature heating pipeline insulation coating. The difference from Example 1 is that the high-temperature resistant layer is uniformly coated with a high-temperature resistant aerogel insulation coating with a dry film thickness of 4 mm. The high-temperature resistant aerogel insulation coating is composed of the following raw materials in parts by weight: 50 parts of perhydropolysilazane, 30 parts of silica aerogel nanoparticles, 15 parts of zirconium oxide nanoparticles, 25 parts of butyl acetate, and 3 parts of γ-glycidyl etheroxypropyltrimethoxysilane.

[0025] Example 4: This invention discloses a high-temperature heating pipeline insulation coating. The difference from Example 1 is that the transition buffer layer is uniformly coated with a 3mm thick room-temperature aerogel insulation coating. The room-temperature aerogel insulation coating is composed of the following raw materials in parts by weight: 25 parts silica aerogel nanoparticles, 40 parts elastic emulsion with a solid content of 52%, 10 parts glass microspheres, 0.1 parts isothiazolinone bactericide, and 5 parts filler additives. Example 5: This invention discloses a high-temperature heating pipeline insulation coating. The difference from Example 1 is that the transition buffer layer is uniformly coated with a room-temperature aerogel insulation coating with a dry film thickness of 5 mm. The room-temperature aerogel insulation coating is composed of the following raw materials in parts by weight: 40 parts of silica aerogel nanoparticles, 55 parts of elastic emulsion with a solid content of 52%, 20 parts of glass microspheres, 0.3 parts of isothiazolinone bactericide, and 8 parts of filler additives.

[0026] Example 6: This is a high-temperature heating pipeline insulation coating disclosed in this invention. The difference from Example 1 is that the waterproof functional layer is uniformly coated with a polymer cement waterproof coating with a dry film thickness of 0.1 mm. The polymer cement waterproof coating is composed of the following raw materials in parts by weight: 50 parts of acrylic emulsion with a solid content ≥50%, 50 parts of ordinary silicate cement, and 0.25 parts of additives.

[0027] Example 7: This invention discloses a high-temperature heating pipeline insulation coating. The difference from Example 1 is that the waterproof functional layer is uniformly coated with a polymer cement waterproof coating with a dry film thickness of 0.3 mm. The polymer cement waterproof coating is composed of the following raw materials in parts by weight: 50 parts of acrylic emulsion with a solid content ≥50%, 75 parts of ordinary silicate cement, and 7.50 parts of additives.

[0028] Comparative Example 1: This is a high-temperature heating pipeline insulation coating disclosed in this invention. The difference from Example 1 is that it does not use a high-temperature resistant layer, a transition buffer layer, and a waterproof functional layer. It uses the same 20G carbon steel substrate, and after surface sandblasting, it is wrapped with a 30mm thick rock wool insulation layer and covered with a 0.5mm thick aluminum sheet as a comparison with traditional insulation solutions.

[0029] Test Example 1: Performance tests were conducted on the pipes with insulation coatings / conventional insulation schemes prepared in Example 1 and Comparative Example 1. The results are shown in Table 1.

[0030] Table 1 Thermal conductivity (W / (m·K)) 0.142 0.046~0.120 (estimated, segmented) HotDisk Transient Flat Panel Heat Source Method Bond strength (300℃, MPa) 0.15 Physical package, no data GB / T5210-2006 Water absorption rate (%) 5.4 Rock wool is prone to absorbing moisture, making it difficult to measure precisely. GB / T1034-2008 Thermal shock resistance (number of cycles) >21 After repeated hot and cold cycles, it is prone to loosening and delamination. 80℃↔ Room temperature water quenching Resistant to damp heat aging (60℃, 90%RH, 168h) No abnormalities in appearance Rock wool's performance deteriorates after absorbing moisture. GB / T2423.3-2016 250℃ steam insulation outlet temperature (°C) 230 Approximately 160 Simulation comparison experiment Temperature range of the outer wall of the pipeline at 173℃ (°C) 42~48 (simulated) 41.5~47.1 (actual measurement) 42~55 (perfect condition) 74.5 (damaged area, actual measurement) Numerical simulation and field measurement Heat flux density range at 173℃ (W / m²) 224~352 (simulated) 188.1~322.3 (actual measurement) 228~496 (perfect condition) 938.4 (damaged area, actual measurement) Numerical simulation and field measurement As shown in Table 1, the gradient composite coating system provided in Example 1 of this invention possesses excellent thermal insulation performance (thermal conductivity 0.138~0.147 W / (m·K)), superior interfacial bonding strength (0.15 MPa at 300℃), and outstanding environmental resistance (resistance to thermal shock >21 cycles, resistance to damp heat aging). Especially in the comparative insulation experiment simulating a 250℃ steam pipeline, the insulation outlet temperature of the coating system of this invention (total thickness 7mm) can reach approximately 230℃, reducing heat loss by more than 40% compared to the traditional 30mm thick rock wool insulation solution (outlet temperature approximately 160℃), demonstrating significant energy-saving effects. Furthermore, this coating system, achieved through spraying and spin coating processes, can uniformly and completely cover irregularly shaped components such as valves and elbows, facilitating construction and overcoming the shortcomings of traditional wrapping materials that easily create gaps and thermal bridges. Its comprehensive performance meets the requirements for long-term thermal insulation and waterproof protection of high-temperature heating pipelines.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A thermal insulation coating for high-temperature heating pipelines, characterized in that: It includes a high-temperature resistant layer, a transition buffer layer, and a waterproof functional layer, which are sequentially disposed on the surface of the pipe from the inside out; wherein, the high-temperature resistant layer is uniformly coated with a high-temperature resistant aerogel insulation coating with a dry film thickness of 2-4 mm, the transition buffer layer is uniformly coated with a room-temperature aerogel insulation coating with a dry film thickness of 3-5 mm, and the waterproof functional layer is uniformly coated with a polymer cement waterproof coating with a dry film thickness of 0.1-0.3 mm.

2. The high-temperature heating pipeline insulation coating according to claim 1, characterized in that: The high-temperature resistant aerogel insulation coating is composed of the following raw materials in parts by weight: 35-50 parts of perhydropolysilazane, 20-30 parts of silica aerogel nanoparticles, 5-15 parts of zirconium oxide nanoparticles, 15-25 parts of butyl acetate, and 1-3 parts of dispersant.

3. The high-temperature heating pipeline insulation coating according to claim 2, characterized in that: The dispersant is γ-glycidoxypropyltrimethoxysilane.

4. The high-temperature heating pipeline insulation coating according to claim 2, characterized in that: The high-temperature resistant layer is made by uniformly spraying a high-temperature resistant aerogel insulation coating onto the pipe surface at a pressure of 0.4~0.8MPa, heating it to above 200℃ at a heating rate of 3~5℃ / min, curing it at a high temperature, holding it at that temperature for 1 hour, and then cooling it. After curing, the thermal conductivity is ≤0.035W / (m·K), the operating temperature range is -30~600℃, and the bonding strength with the pipe is ≥0.6MPa at 300℃.

5. The high-temperature heating pipeline insulation coating according to claim 1, characterized in that: The room temperature aerogel insulation coating is composed of the following raw materials in parts by weight: 25-40 parts silica aerogel nanoparticles, 40-55 parts elastic emulsion, 10-20 parts glass microspheres, 0.1-0.3 parts isothiazolinone bactericide, and 5-8 parts filler additives.

6. The high-temperature heating pipeline insulation coating according to claim 5, characterized in that: The elastic emulsion has a solid content of ≥50%.

7. The high-temperature heating pipeline insulation coating according to claim 5, characterized in that: The transition buffer layer is formed by uniformly spraying a room temperature aerogel insulation coating onto the surface of the high temperature resistant layer at a pressure of 0.4~0.8MPa, then heating it to a high temperature above 200℃ at a heating rate of 3~5℃ / min and curing it. After curing, it is surface dried at an environment of ≥5℃ for 5~7 hours. The thermal conductivity after curing is ≤0.036W / (m·K), and the long-term service temperature is below 100℃.

8. The high-temperature heating pipeline insulation coating according to claim 1, characterized in that: The polymer cement waterproof coating is composed of the following raw materials in parts by weight: 50 parts acrylic emulsion, 50-75 parts ordinary silicate cement, and 0.25-7.50 parts additives.

9. The high-temperature heating pipeline insulation coating according to claim 8, characterized in that: The solid content of the acrylate emulsion is ≥50%.

10. The high-temperature heating pipeline insulation coating according to claim 8, characterized in that: The waterproof functional layer is prepared by uniformly spinning polymer cement waterproof coating on the surface of the transition buffer layer at 800~1200 rpm at least twice, with the time interval between each spin coating controlled at 20~40 min, and then curing at room temperature; after curing, the tensile strength is ≥1.8MPa, the elongation at break is ≥200%, the bond strength is ≥0.6MPa, and the water vapor transmission rate is ≤0.15g / (㎡·h).