A pipeline heat insulation structure

Abstract

The present invention discloses a pipeline heat insulation structure, which includes an inner heat insulation structure layer and an outer heat insulation structure layer sleeved inside and outside. The inner heat insulation structure layer contains heat insulation material units (2) and support structure units (4) alternately arranged along the circumferential direction of the pipeline heat insulation structure. The thermal conductivity of the heat insulation material units (2) is less than or equal to 0.041 W / mk, and the compressive strength of the support structure units (4) is greater than or equal to 4 Mpa. This pipeline heat insulation structure can reduce the heat loss of long-distance heat transmission pipelines. This pipeline heat insulation structure can be used for directly buried steam pipelines and can also be applied to the laying of overhead steam pipelines, and has the advantages of simple processing and strong adaptability.

Description

Technical Field

[0001] The present invention relates to the technical field of pipeline heat insulation, and specifically to a pipeline heat insulation structure. Background Art

[0002] At present, in the conventional design technology of steam pipe networks, the transmission distance of steam pipe networks is generally 5 kilometers to 8 kilometers, and the longest does not exceed 10 kilometers. However, since the location of power plants is generally not at the center of steam heat load, according to the current design specifications, the steam heating radius is generally between 5 kilometers and 8 kilometers, far from reaching the heating radius of each power plant. Therefore, it is necessary to expand the steam heating radius and increase the transmission distance of the steam pipe network to meet the external heating demand for long-distance heat transportation in centralized heating.

[0003] However, restricted by the existing technology, the temperature drop of long-distance heat transportation steam pipelines is serious, the heat loss is large, the heating radius is greatly limited, and it cannot meet the requirements of long-distance terminal heating users, resulting in many enterprises being unable to adopt centralized heating. Summary of the Invention

[0004] In order to improve the efficiency of long-distance heat transportation pipelines, the present invention provides a pipeline heat insulation structure, which can reduce the heat loss of long-distance heat transportation pipelines. This pipeline heat insulation structure can be used for directly buried steam pipelines and can also be applied to the laying of overhead steam pipelines, and has the advantages of simple processing and strong adaptability.

[0005] The technical solution adopted by the present invention to solve its technical problems is: a pipeline heat insulation structure, including an inner heat insulation structure layer and an outer heat insulation structure layer sleeved inside and outside. The inner heat insulation structure layer contains heat insulation material units and support structure units alternately arranged along the circumferential direction of the pipeline heat insulation structure. The thermal conductivity of the heat insulation material units is less than or equal to 0.041W / mk, and the compressive strength of the support structure units is greater than or equal to 4Mpa.

[0006] The material of the heat insulation material units is inorganic fiber heat insulation material, and the thermal conductivity of the support structure units is less than or equal to 0.2W / mk.

[0007] The support structure units are pine blocks.

[0008] The support structure units contain vermiculite, or the support structure units contain foam glass, or the support structure units contain vermiculite and foam glass.

[0009] Along the radial direction of the pipeline heat insulation structure, the inner surface of the support structure units is provided with high-temperature resistant friction plates, which can reduce the friction force between the support structure units and the heat transportation pipeline.

[0010] Radially along the pipeline heat insulation structure, the inner surface of the support structure unit is in a serrated structure, and a plurality of strip-shaped convex ribs are provided on the inner surface of the support structure unit, and the plurality of strip-shaped convex ribs are evenly spaced along the circumferential direction of the pipeline heat insulation structure.

[0011] The heat insulation material unit is aluminosilicate needled blanket, and the distance between two adjacent support structure units located above the inner heat insulation structure layer is greater than the distance between two adjacent support structure units located below the inner heat insulation structure layer.

[0012] The outer heat insulation structure layer includes a first reflective layer, a first outer heat insulation layer, a second reflective layer, a second outer heat insulation layer, a third reflective layer and an outer steel casing sleeved in sequence from inside to outside.

[0013] The first reflective layer, the second reflective layer and the third reflective layer are all aluminum foil fiberglass cloth composite reflective layers, and the first outer heat insulation layer and the second outer heat insulation layer are both high-temperature resistant glass wool layers.

[0014] The pipeline heat insulation structure further includes a pipe clamp type support seat, and the pipe clamp type support seat includes an upper support, a lower support and a base arranged in sequence from top to bottom. The inner heat insulation structure layer and the outer heat insulation structure layer are both located between the upper support and the lower support. The upper support and the lower support are connected by bolts, and a polytetrafluoroethylene cushion plate is provided between the lower support and the base.

[0015] The beneficial effects of the present invention are as follows: This pipeline heat insulation structure combines mature heat insulation materials in the market, changes the structure of the original heat insulation pipeline and the form of the heat insulation structure in contact with the pipeline in the structure, simplifies the processing technology, enhances the heat insulation effect of the steam pipeline, and effectively reduces the temperature drop of the long-distance heat transport steam pipeline; it improves the stress condition of the working pipe system of the directly buried and overhead steam pipelines, increases the service life of the pipeline in the long-distance transportation system, and improves the stability and reliability of the system operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The specification drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0017] Figure 1 It is a schematic diagram of the first implementation manner of the pipeline heat insulation structure of the present invention.

[0018] Figure 2 It is a schematic diagram of the second implementation manner of the pipeline heat insulation structure of the present invention.

[0019] Figure 3 It is a schematic diagram of the third implementation manner of the pipeline heat insulation structure of the present invention.

[0020] Figure 4It is a schematic diagram of the fourth implementation manner of the pipeline heat insulation structure described in the present invention.

[0021] Figure 5 It is Figure 1 a partial unfolded schematic diagram of the inner surface of the inner heat insulation structure layer in

[0022] Figure 6 It is Figure 2 a partial unfolded schematic diagram of the inner surface of the inner heat insulation structure layer in

[0023] Figure 7 a schematic diagram showing that the inner surface of the support structure unit is in a serrated structure.

[0024] 1. Heat transfer pipeline; 2. Heat insulation material unit; 3. High-temperature friction plate; 4. Support structure unit; 5. First reflective layer; 6. First outer heat insulation layer; 7. Second reflective layer; 8. Second outer heat insulation layer; 9. Third reflective layer; 10. Outer steel casing; 11. Pipe clamp type support.

[0025] 111. Upper support; 112. Lower support; 113. Base; 114. Teflon cushion plate. Specific implementation manners

[0026] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0027] A pipeline heat insulation structure includes an inner heat insulation structure layer and an outer heat insulation structure layer which are nested inside and outside. The inner heat insulation structure layer contains heat insulation material units 2 and support structure units 4 which are alternately arranged along the circumferential direction of the pipeline heat insulation structure. The thermal conductivity of the heat insulation material unit 2 is less than or equal to 0.041 W / mk, and the compressive strength of the support structure unit 4 is greater than or equal to 4 Mpa, as Figures 1 to 4 shown.

[0028] In this embodiment, the main function of the heat insulation material unit 2 is heat insulation. The material of the heat insulation material unit 2 is an existing inorganic fiber heat insulation material. For example, the heat insulation material unit 2 is cut and processed from an existing aluminum silicate needle felt. The main function of the support structure unit 4 is support. The support structure unit 4 should have good compressive capacity, and at the same time, it should also have certain heat insulation performance. Preferably, the thermal conductivity of the support structure unit 4 is less than or equal to 0.2 W / mk, the compressive strength of the support structure unit 4 is greater than or equal to 4 Mpa, and the compressive strength of the support structure unit 4 is less than or equal to 40 Mpa.

[0029] In this embodiment, the cross-section of the heat insulation material unit 2 is fan-shaped, and the cross-section of the support structure unit 4 is rectangular, as Figures 1 to 4As shown. The support structure unit 4 can be a pine block, which can also be called a pine strip. The support structure unit 4 can be made of vermiculite and an adhesive, and the ratio of the vermiculite to the adhesive can be determined based on a limited number of tests. Alternatively, the support structure unit 4 is made of foam glass.

[0030] The composite insulation structure of the insulation material unit 2 (such as an aluminum silicate needle punched blanket) and the support structure unit 4 (such as a high-strength insulation block) close to the outer wall of the heat transfer pipeline 1 has the advantages that the aluminum silicate needle punched blanket can maintain a low linear change rate, high flexural strength, and low thermal conductivity at a higher temperature, and can continue to effectively play an insulation role at high temperatures; the high-strength insulation block can support the inner insulation structure to ensure the stability of the inner insulation structure, so that the aluminum silicate needle punched blanket can still maintain its original size and structure in an environment of high temperature and repeated temperature changes, and will not increase its internal fiber voids due to repeated high-temperature-low-temperature cycle conditions. In addition, the high-strength support can also prevent the insulation material from collapsing during the service life of the working pipeline.

[0031] In this embodiment, in order to reduce the friction between the support structure unit 4 and the heat transfer pipeline 1, a high temperature resistant friction plate 3 is provided on the inner surface of the support structure unit 4 along the radial direction of the pipeline insulation structure. The material of the high temperature resistant friction plate 3 is the existing high temperature resistant polytetrafluoroethylene. The support structure unit 4 is stacked and connected with the high temperature resistant friction plate 3. The high temperature resistant friction plate 3 can reduce the friction between the support structure unit 4 and the heat transfer pipeline 1. Figure 1 , Figure 3 and Figure 5 The high temperature resistant friction plate 3 can be connected and fixed to the supporting structure unit 4, or the high temperature resistant friction plate 3 can also be connected and fixed to the heat transfer pipeline 1. The thickness of the high temperature resistant friction plate 3 can be determined according to needs or obtained according to a limited number of tests.

[0032] A high temperature resistant friction sheet 3 is arranged between the support structure unit 4 and the heat transfer pipe 1, so that the heat transfer pipe 1 can achieve thermal displacement with low friction resistance in the insulation structure under the condition of alternating cold and hot cycles, improve the thermal stress of the heat transfer pipe 1, reduce the friction between the heat transfer pipe 1 and the insulation material, and thus reduce the destructiveness of the pipe friction to the composite insulation material. The high temperature resistant friction sheet 3 can be placed on the top of the support structure unit 4, and the support structure unit 4 is evenly embedded in the aluminum silicate needle-punched blanket, and batch prefabrication and processing into an integrated product is convenient for the construction of on-site insulation materials.

[0033] In this embodiment, in order to reduce the friction between the support structure unit 4 and the heat transfer pipe 1, the inner surface of the support structure unit 4 is a serrated structure along the radial direction of the pipe insulation structure, and the inner surface of the support structure unit 4 is provided with a plurality of strip convex ridges, and the plurality of strip convex ridges are evenly spaced along the circumference of the pipe insulation structure, such asFigure 2 , Figure 4 , Figure 6 and Figure 7 as shown.

[0034] In this embodiment, along the circumferential direction of the pipeline thermal insulation structure, the arrangement density of the support structure units 4 can be the same, as Figure 1 and Figure 2 shown. For example, the included angle between two adjacent support structure units 4 is 45 degrees. Alternatively, along the circumferential direction of the pipeline thermal insulation structure, the arrangement density of the support structure units 4 can also be different, as Figure 3 and Figure 4 shown. The arrangement density of the support structure units 4 located in the upper part of the inner thermal insulation structure layer is less than that of the support structure units 4 located in the lower part of the inner thermal insulation structure layer.

[0035] Specifically, the distance between two adjacent support structure units 4 located in the upper part of the inner thermal insulation structure layer is greater than the distance between two adjacent support structure units 4 located in the lower part of the inner thermal insulation structure layer. The included angle between two adjacent support structure units 4 located in the upper part of the inner thermal insulation structure layer is 45 degrees, and the included angle between two adjacent support structure units 4 located in the lower part of the inner thermal insulation structure layer is 30 degrees.

[0036] In this embodiment, the outer thermal insulation structure layer includes a first reflective layer 5, a first outer thermal insulation layer 6, a second reflective layer 7, a second outer thermal insulation layer 8, a third reflective layer 9, and an outer protective steel sleeve 10 that are sequentially stacked and sleeved from the inside out. The first reflective layer 5, the second reflective layer 7, and the third reflective layer 9 are all existing aluminum foil fiberglass cloth composite reflective layers, and the first outer thermal insulation layer 6 and the second outer thermal insulation layer 8 are both existing high-temperature resistant glass wool layers.

[0037] The aluminum foil fiberglass cloth composite reflective layer uses high-purity aluminum foil, so that the high-temperature thermal radiation of the working pipe is reflected by the aluminum foil multiple times, thereby effectively reducing the radiant heat loss in the pipeline. The high-temperature resistant glass wool can maintain a stable thermal conductivity at high temperatures and has strong hydrophobicity, which can prevent the condensate water generated due to the temperature difference between the working pipe and the environment from penetrating towards the working pipeline. The aluminum foil fiberglass cloth composite reflective layer outside the high-temperature resistant glass wool can effectively reduce the radiant heat loss in the pipeline.

[0038] In this embodiment, the pipeline thermal insulation structure, the inner thermal insulation structure layer, and the outer thermal insulation structure layer are all cylindrical structures, and the axes of the inner thermal insulation structure layer, the outer thermal insulation structure layer, and the heat transfer pipeline 1 coincide. The axes of the inner thermal insulation structure layer, the first reflective layer 5, the first outer thermal insulation layer 6, the second reflective layer 7, the second outer thermal insulation layer 8, the third reflective layer 9, and the outer protective steel sleeve 10 coincide.

[0039] When the pipeline thermal insulation structure is used for directly buried heat transmission pipelines, it can be as shown in Figure 1 and Figure 3 , that is, the pipeline thermal insulation structure is directly sleeved outside the heat transmission pipeline 1, and the outer diameter of the inner thermal insulation structure layer is equal to the outer diameter of the heat transmission pipeline 1. When the pipeline thermal insulation structure is used for overhead heat transmission pipeline laying, it can be as shown in Figure 2 and Figure 4 , the pipeline thermal insulation structure further includes a pipe clamp type support 11. The pipe clamp type support 11 includes an upper bracket 111, a lower bracket 112 and a base 113 arranged in sequence from top to bottom. The inner thermal insulation structure layer and the outer thermal insulation structure layer are arranged between the upper bracket 111 and the lower bracket 112. The upper bracket 111 and the lower bracket 112 are connected by bolts, and a polytetrafluoroethylene gasket 114 is provided between the lower bracket 112 and the base 113.

[0040] The main function of the inner thermal insulation structure layer is heat insulation, and the main functions of the outer thermal insulation structure layer are heat insulation and reflection. A composite thermal insulation structure of aluminum silicate needle punched blanket and high-strength heat insulation blocks is arranged closely to the heat transmission pipeline 1 to reduce the convective heat transfer amount of the heat transmission pipeline 1. An aluminum foil fiberglass cloth composite reflection layer is arranged on the outer layer to reduce the radiative heat transfer amount of the heat transmission pipeline 1. The outer layer sequentially adopts high-temperature glass wool, aluminum foil fiberglass cloth composite reflection layer, high-temperature glass wool, aluminum foil fiberglass cloth composite reflection layer, and the outer protection steel sleeve 10 adopts a spiral welded steel pipe.

[0041] Due to its large pressure resistance strength, good heat insulation and adiabatic effect, and wide adaptability to working conditions, this pipeline thermal insulation structure can not only be applied to the thermal insulation structure of directly buried steam pipelines, but also to the thermal insulation structure of overhead steam pipelines. Combined with the existing pipe clamp support structure, it can be applicable to various working conditions such as direct burial and overhead.

[0042] The materials of the components used in the present invention are all existing commercially available products. For example, the thermal insulation material unit 2 is processed from aluminum silicate needle punched blanket. The support structure unit 4 can adopt vermiculite, pine blocks or foam glass, and can be flexibly selected according to different engineering requirements. Integrating the mature aluminum silicate needle punched blanket material on the market with the support structure unit 4 and high-temperature friction plates into an integrated material is convenient for batch customized production and on-site installation. The aluminum silicate needle punched blanket and high-strength heat insulation blocks play a role of mutual enhancement. The aluminum silicate needle punched blanket is inexpensive and can maintain a low thermal conductivity for a long time at a relatively high temperature, while the high-strength heat insulation blocks are clamped in the aluminum silicate needle punched blanket, playing a framework role, enabling the structure of the aluminum silicate needle punched blanket to be more stable and not changing the internal fiber structure due to the high temperature of the working pipe, thereby extending its high-efficiency heat insulation life.

[0043] In order to reduce the processing difficulty and product cost of the above composite structure, high-strength insulation blocks are set at 45° angles or other angles on the aluminum silicate needle-punched blanket material surrounding the working tube to take into account both strength and thermal insulation performance. Figure 1 and Figure 3 Optimized to Figure 2 and Figure 4 The lower part of the insulation structure needs to bear a greater load (the weight of the pipe and the medium in the pipe) than the upper part of the insulation structure. Figure 2 and Figure 4 The supporting structure units 4 in the lower part of the structure are at an angle of 30° or other denser angles, thereby improving the supporting strength of the insulation structure to the pipeline. Figure 1 , Figure 3 still Figure 2 , Figure 4 , which can be flexibly selected according to project cost, etc.

[0044] For buried steam pipelines, since the pipeline needs to achieve thermal displacement within the outer protective pipe, in order to reduce the friction between the innermost layer of composite insulation material and the steam pipeline (such as Figure 5 As shown in the structure, a high temperature resistant friction plate 3 is arranged on the contact surface between the support structure unit 4 and the heat transfer pipeline 1 to reduce the friction between the heat transfer pipeline 1 and the insulation material. For the heat transfer pipeline 1, smaller friction can make its thermal expansion more sufficient, and good thermal displacement can release the concentrated thermal stress of the working pipe under high temperature, improve the thermal stress of the steam pipe system, and the reduction of thermal stress will greatly improve the service life of the pipeline and accessories, and can enhance the safety and reliability of the long-distance heat transport system; for the overhead steam pipeline, since the pipe clamp bracket is provided with a tetrafluoroethylene pad 114 under the pipe clamp bracket, the thermal displacement of the steam pipeline can be achieved through the pipe clamp bracket, so the innermost insulation structure in the pipe clamp and the pipeline are not relatively displaced as much as possible, and the contact surface between the high-strength insulation block and the pipeline is processed into a serrated shape (such as Figure 7 as shown) or other structures that increase friction.

[0045] The efficient direct buried steam pipeline containing the pipeline insulation structure of the present invention can be used for long-distance direct burial or overhead laying in the long-distance heat transport of steam. Under the cold-heat cycle conditions of the heating season and the non-heating season and different steam temperatures in the same heating season, the high-temperature resistant friction plate 3 in close contact with the working pipeline can adapt to the repeated changes of the working pipe from 400° to the ambient temperature without damaging the insulation material due to repeated friction, and the high-strength insulation block can better enhance the stability of the insulation structure, thereby ensuring the efficient and stable operation of the steam pipeline. At the same time, the outer aluminum foil glass fiber cloth composite reflective layer adopts high-purity aluminum foil, which can effectively reduce the heat radiation loss of the working pipeline and effectively reduce the temperature drop of the long-distance heat transport steam pipeline, thereby achieving the purpose of increasing the heating radius.

[0046] As described above, the above are only specific embodiments of the present invention, and the scope of the invention cannot be limited thereby. Therefore, the replacement of equivalent components, or equivalent changes and modifications made according to the scope of protection of the present invention, should still fall within the scope covered by this patent. In addition, the technical features in the present invention, between technical features, between technical features and technical solutions, and between technical solutions can be freely combined and used.

Claims

1. A pipeline heat insulation structure, characterized in that, The pipeline heat insulation structure includes an inner heat insulation structure layer and an outer heat insulation structure layer which are sleeved inside and outside. The inner heat insulation structure layer contains heat insulation material units (2) and support structure units (4) that are alternately arranged along the circumferential direction of the pipeline heat insulation structure. The heat transfer coefficient of the heat insulation material unit (2) is less than or equal to 0.041 W / mk, and the compressive strength of the support structure unit (4) is greater than or equal to 4 Mpa; The heat transfer coefficient of the support structure unit (4) is less than or equal to 0.2 W / mk; Along the radial direction of the pipeline heat insulation structure, the inner surface of the support structure unit (4) in contact with the pipeline is in a serrated structure. The inner surface of the support structure unit (4) is provided with a plurality of strip-shaped convex ribs, and the plurality of strip-shaped convex ribs are evenly spaced along the circumferential direction of the pipeline heat insulation structure; The outer heat insulation structure layer contains a first reflective layer (5), a first outer heat insulation layer (6), a second reflective layer (7), a second outer heat insulation layer (8), a third reflective layer (9) and an outer steel casing (10) that are sleeved in sequence from the inside to the outside.

2. The pipeline heat preservation structure according to claim 1, wherein The material of the heat insulation material unit (2) is inorganic fiber heat insulation material.

3. The pipeline heat insulation structure according to claim 1, characterized in that The support structure unit (4) is a pine block.

4. The pipeline heat insulation structure according to claim 1, characterized in that The support structure unit (4) contains vermiculite, or the support structure unit (4) contains foam glass, or the support structure unit (4) contains vermiculite and foam glass.

5. The pipeline heat insulation structure according to claim 1, characterized in that, Along the radial direction of the pipeline heat insulation structure, a high-temperature resistant friction plate (3) is provided on the inner surface of the support structure unit (4), and the high-temperature resistant friction plate (3) can reduce the friction force between the support structure unit (4) and the heat transfer pipeline (1).

6. The pipeline heat insulation structure according to claim 1, characterized in that, The heat insulation material unit (2) is a needle-punched aluminosilicate blanket, and the distance between adjacent two support structure units (4) located in the upper part of the inner heat insulation structure layer is greater than the distance between adjacent two support structure units (4) located in the lower part of the inner heat insulation structure layer.

7. The pipeline heat preservation structure according to claim 1, characterized in that The first reflective layer (5), the second reflective layer (7) and the third reflective layer (9) are all aluminum foil fiberglass cloth composite reflective layers, and the first outer heat insulation layer (6) and the second outer heat insulation layer (8) are both high-temperature resistant glass wool layers.

8. The pipeline heat insulation structure according to claim 1, characterized in that, The pipeline heat insulation structure further includes a pipe clamp type support (11). The pipe clamp type support (11) contains an upper support (111), a lower support (112) and a base (113) that are arranged in sequence from top to bottom. The inner heat insulation structure layer and the outer heat insulation structure layer are both located between the upper support (111) and the lower support (112). The upper support (111) and the lower support (112) are connected by bolts, and a polytetrafluoroethylene backing plate (114) is provided between the lower support (112) and the base (113).

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