Multi-layer reflection type high-temperature pipeline heat preservation structure based on heat transfer mechanism partition design

Abstract

The multi-layer reflection type high-temperature pipeline heat preservation structure based on the heat transfer mechanism partition design comprises a working steel pipe, and a first heat preservation layer, a second heat preservation layer, a third heat preservation layer and a fourth heat preservation layer are sequentially arranged on the outer side of the working steel pipe; air thin layers are arranged on the inner side and the outer side of the first reflecting layer, the second heat preservation layer comprises a plurality of second reflecting layers and first high-temperature-resistant heat preservation cotton layers, the second reflecting layers and the first high-temperature-resistant heat preservation cotton layers are arranged alternately, the third heat preservation layer is a second high-temperature-resistant heat preservation cotton layer, and the fourth heat preservation layer is a conventional heat preservation cotton layer. The structure can fully restrain radiation heat loss of a high-temperature area near the working steel pipe; the multi-layer reflection structure and the air gap layer are fixed through the discrete gaskets, a solid heat transfer heat bridge along the supporting gaskets can be effectively broken, local heat loss is reduced, meanwhile, the characteristic of low heat conductivity of air can be fully utilized, and convective heat transfer between air layers is restrained to the maximum extent.

Description

Technical Field

[0001] This invention relates to the technical field of high-temperature pipeline insulation, specifically to a multi-layer reflective high-temperature pipeline insulation structure based on a heat transfer mechanism zoning design, which is particularly suitable for high-temperature pipeline insulation structures transporting media with temperatures above 300°C. Background Technology

[0002] Reducing carbon emissions is a key goal for human development, and advanced thermal insulation technology can improve energy efficiency, making it one of the most economical means of carbon reduction. In the chemical and energy sectors, thermal pipeline systems are widely used. The temperatures of the media transported in these pipelines are generally above 300℃, and radiative heat transfer accounts for a significant proportion of heat loss. Traditional high-temperature pipeline insulation mainly uses single-alumina silicate or aerogel materials. While these can reduce conductive heat loss, they cannot effectively suppress radiative heat loss. Furthermore, aerogel materials are expensive, making single-aerogel insulation less economical. Existing invention patents, such as patent "201310021044.8 Low-energy steam conveying pipe system" and patent "201811054449.0 An overhead steam pipe insulation structure and its construction method", use aluminum silicate as the inner layer and glass wool as the outer layer, and arrange a reflective layer on the outside of each insulation layer. The insulation structure uses two types of insulation wool with different temperature resistance to reduce the insulation cost. However, the method of arranging a reflective layer on the outside of each insulation layer cannot effectively suppress radiative heat transfer, because radiative heat transfer accounts for a large proportion only at high temperatures, and the reflective layer is in direct contact with the insulation wool, so most of the heat is lost through heat conduction. For example, in patents “202010794389.7 A pipe insulation structure” and “202411643567.0 A high-temperature thermal pipe insulation structure and high-temperature thermal pipe”, an air layer is added between the working steel pipe and the insulation cotton, and a single-layer reflective layer is set. This can reduce radiative heat transfer to a certain extent. However, if the air layer is too thick, it will generate natural convection, which will lead to an increase in convective heat loss. Moreover, the single reflective layer has limited effect on shielding radiation.

[0003] In summary, existing high-temperature pipeline insulation technologies still have shortcomings and cannot comprehensively suppress heat loss caused by different heat transfer mechanisms. Therefore, optimizing the design of insulation structures from the perspective of heat transfer mechanisms to achieve comprehensive suppression of conduction, convection, and radiation is the key to the future development of high-efficiency insulation technologies. Summary of the Invention

[0004] To address the aforementioned technical problems in related technologies, this invention provides a multi-layer reflective high-temperature pipeline insulation structure based on a heat transfer mechanism partition design, which can solve the above problems.

[0005] To achieve the above-mentioned technical objectives, the technical solution of the present invention is implemented as follows: A multi-layer reflective high-temperature pipeline insulation structure based on a heat transfer mechanism zoning design includes a working steel pipe. The outer side of the working steel pipe is sequentially provided with a first insulation layer, a second insulation layer, a third insulation layer, and a fourth insulation layer. The first insulation layer includes multiple annular reflective layers. Several rows of gasket arrays arranged axially are bonded to the inner and outer walls of the reflective layers. Each gasket array includes a first gasket array and a second gasket array, which are arranged alternately. Both the first and second gasket arrays contain... There are several hemispherical pads distributed at equal intervals. The gap between two adjacent pads in the first pad array is opposite to the pads in the second pad array. The pad arrays on two adjacent reflective layers are staggered in the circumferential direction. The inner and outer sides of the first reflective layer are provided with thin air layers. The second insulation layer includes several reflective layers and high-temperature resistant insulation cotton layers. The reflective layers and the high-temperature resistant insulation cotton layers are arranged alternately. The third insulation layer is a high-temperature resistant insulation cotton layer and the fourth insulation layer is a conventional insulation cotton layer.

[0006] Furthermore, the gasket is made of high-temperature resistant thermal insulation mortar, and the horizontal end face of the gasket is bonded to the reflective layer by high-temperature resistant adhesive. The height of the gasket is 2mm.

[0007] Furthermore, both the first reflective layer and the second reflective layer include a metal foil surface facing the high-temperature side and a fiberglass cloth surface facing the low-temperature side.

[0008] Furthermore, the spacing between adjacent reflective layers is no greater than 3 mm.

[0009] Furthermore, the first and second high-temperature resistant insulation cotton layers are made of aluminum silicate needle-punched blankets.

[0010] Furthermore, the conventional insulation layer is made of centrifugal glass wool.

[0011] Furthermore, the outer side of the fourth insulation layer is provided with a moisture-proof layer and a protective layer.

[0012] The beneficial effects of this invention are as follows: The structure of this application can effectively suppress radiative heat loss in the high-temperature area near the working steel pipe; the structure of this application uses discrete gaskets to fix the multi-layer reflective structure and air gap layer, which can effectively break the solid heat transfer bridge along the supporting gasket and reduce local heat loss; the air gap layer included in this application is thin and multi-layered, which, compared with the traditional insulation structure containing air layers, can suppress heat loss caused by natural air convection while utilizing the low thermal conductivity of air; the insulation effect of the structure of this application is better than the traditional composite insulation structure with aluminum silicate inner layer, glass wool outer layer and reflective layer arranged outside each insulation layer, while the insulation cost is similar to the above structure; the insulation cost of the structure of this application is lower than the insulation structure using aerogel. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] The present invention will now be described in further detail with reference to the accompanying drawings.

[0015] Figure 1 This is a cross-sectional view of the multi-layer reflective high-temperature pipeline insulation structure based on heat transfer mechanism partitioning design as described in the embodiment of the present invention; Figure 2 This is a front view of the unfolded reflective layer according to an embodiment of the present invention; Figure 3 This is a top view of the unfolded reflective layer according to an embodiment of the present invention.

[0016] In the picture: 1. First insulation layer; 11. Reflective layer one; 12. Gasket array; 121. Gasket array one; 122. Gasket array two; 13. Gasket; 14. Air layer; 2. Second insulation layer; 3. Third insulation layer; 4. Fourth insulation layer; 5. Working steel pipe. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0018] like Figure 1-3 As shown, the present invention discloses a multi-layer reflective high-temperature pipeline insulation structure based on a heat transfer mechanism zoning design, including a working steel pipe 5. The outer side of the working steel pipe 5 is provided with a first insulation layer 1, a second insulation layer 2, a third insulation layer 3, and a fourth insulation layer 4 in sequence. The first insulation layer 1 includes multiple annular reflective layers 11 (3 to 5 layers, adjusted according to the temperature of the conveying medium). Air thin layers 14 are provided on both the inner and outer sides of the reflective layers 11. The second insulation layer 2 includes several reflective layers 2 (3 to 5 layers, adjusted according to the temperature of the conveying medium) and a high-temperature resistant insulation cotton layer 1. The reflective layers 2 and the high-temperature resistant insulation cotton layer 1 are arranged alternately. The third insulation layer 3 is a high-temperature resistant insulation cotton layer 2, and the fourth insulation layer 4 is a conventional insulation cotton layer.

[0019] In one specific embodiment of this application, several rows of gasket arrays 12 (including gasket array one 121 and gasket array two 122) arranged axially are bonded to the inner and outer walls of the reflective layer one 11. The gasket array one 121 and gasket array two 122 are arranged alternately. Both gasket array one 121 and gasket array two 122 include several hemispherical gaskets 13 distributed at equal intervals. The gaskets 13 can prevent air convection. At the same time, the gap space between two adjacent gaskets 13 in gasket array one 121 is opposite to the gaskets 13 in gasket array two 122, which can further reduce the natural convection of the air layer. The gasket arrays 12 on two adjacent reflective layers one 11 are staggered in the circumferential direction to prevent the gaskets 13 from forming solid heat transfer thermal bridges.

[0020] In a specific embodiment of this application, the gasket 13 is hemispherical to reduce the contact area between the gasket 13 and the supporting surface, thereby reducing the solid thermal conductivity through the gasket 13. The gasket 13 is made of high-temperature resistant thermal insulation mortar (with a large number of tiny pores inside that effectively prevent heat transfer and reduce the thermal conductivity; it does not burn or deform at high temperatures, maintaining structural integrity). The high-temperature resistant thermal insulation mortar contains materials such as expanded vermiculite, perlite powder, and glass microspheres.

[0021] In a specific embodiment of this application, the height of the gasket 13 is 2 mm, so that the thickness of the several air layers 14 formed is no more than 2 mm. Compared with the traditional insulation structure containing air layers, it can suppress heat loss caused by natural air convection while utilizing the low thermal conductivity of air.

[0022] In a specific embodiment of this application, the temperature in the area where the second insulation layer 2 is located is still relatively high, and the proportion of radiative heat transfer is still relatively large. Therefore, the second reflective layer in the second insulation layer 2 should be arranged closely, and the interval between adjacent second reflective layers should not be greater than 3mm.

[0023] In a specific embodiment of this application, a single high-temperature resistant insulation cotton is used as the third insulation layer 3 on the outside of the second insulation layer 2. The temperature of the area where the third insulation layer 3 is located is lower than that of the areas where the first insulation layer 1 and the second insulation layer 2 are located, and the proportion of radiative heat transfer is lower. However, the temperature still exceeds the upper limit of the temperature resistance of conventional insulation cotton. Therefore, the use of high-temperature resistant insulation cotton plays a protective role for conventional insulation cotton.

[0024] In a specific embodiment of this application, a single conventional insulation cotton is used as the fourth insulation layer 4 on the outside of the third insulation layer 3. The conventional insulation cotton has better economy and insulation properties than the high temperature resistant insulation cotton. In the temperature range below 200°C, the advantages of the conventional insulation cotton material can be fully utilized and overheating can be prevented.

[0025] In a specific embodiment of this application, if the third insulation layer 3 and the fourth insulation layer 4 are designed to be thick, they should be laid in layers, and the thickness of each layer should be approximately equal and not greater than 50mm (if the designed thickness is less than 50mm, only one layer is laid) in order to reduce the increased heat dissipation caused by excessive gaps between insulation layers.

[0026] In a specific embodiment of this application, both the first reflective layer 11 and the second reflective layer include a metal foil surface facing the high-temperature side and a fiberglass cloth surface facing the low-temperature side. The metal used for the metal foil surface should have the characteristics of low infrared emissivity and high-temperature oxidation resistance, and can be nickel foil or aluminum foil.

[0027] In a specific embodiment of this application, the first and second high-temperature resistant insulation cotton layers are made of aluminum silicate needle-punched blankets, and the conventional insulation cotton layer is made of centrifugal glass wool.

[0028] In one specific embodiment of this application, the fourth insulation layer is made of centrifugal glass wool, which has a high porosity. If it absorbs water vapor, rainwater, or ambient moisture from the air, its insulation effect will be weakened, and its overall structural stability will be compromised. Therefore, a moisture-proof layer is provided on the outside of the fourth insulation layer. The moisture-proof layer can be made of asphalt mastic, polyvinyl chloride (PVC) waterproof membrane, ethylene propylene diene monomer (EPDM) membrane, single-component polyurethane waterproof coating, acrylic waterproof coating, etc. The moisture-proof layer (especially membranes and coatings) has low physical strength and is easily damaged. Therefore, a protective layer can be provided on the outside of the moisture-proof layer. The protective layer can be made of galvanized steel plate, aluminum alloy plate, color steel plate, etc.

[0029] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A multi-layer reflective high-temperature pipeline insulation structure based on zoning design of heat transfer mechanism, comprising a working steel pipe (5), characterized in that, The outer side of the working steel pipe (5) is sequentially provided with a first heat preservation layer (1), a second heat preservation layer (2), a third heat preservation layer (3) and a fourth heat preservation layer (4), the first heat preservation layer (1) comprises a plurality of annular reflection layers (11), the inner and outer walls of the reflection layer (11) are bonded with a plurality of column gasket arrays (12) arranged in the axial direction, the gasket array (12) comprises a gasket array (121) and a gasket array (122), the gasket array (121) and the gasket array (122) are arranged alternately, the gasket array (121) and the gasket array (122) each comprise a plurality of equidistantly distributed hemispherical gaskets (13), the gap space between the adjacent two gaskets (13) in the gasket array (121) is arranged opposite to the gasket (13) in the gasket array (122), the gasket arrays (12) on the adjacent two reflection layers (11) are arranged in a circumferential direction staggered, the inner and outer sides of the reflection layer (11) are provided with air thin layers (14), the second heat preservation layer (2) comprises a plurality of reflection layers (2) and a high-temperature-resistant heat preservation cotton layer (1), the reflection layer (2) and the high-temperature-resistant heat preservation cotton layer (1) are arranged alternately, the third heat preservation layer (3) is a high-temperature-resistant heat preservation cotton layer (2), and the fourth heat preservation layer (4) is a conventional heat preservation cotton layer.

2. The multi-layer reflective high temperature piping insulation structure based on zoning design of heat transfer mechanisms as claimed in claim 1, wherein, The gasket (13) is made of high-temperature-resistant heat preservation mortar, the horizontal end face of the gasket (13) is bonded to the reflection layer (11) through high-temperature-resistant glue, and the height of the gasket (13) is 2mm.

3. The multi-layer reflective high temperature piping insulation structure based on zoning design of heat transfer mechanisms as claimed in claim 1, wherein, The reflection layer (11) and the reflection layer (2) each comprise a metal foil surface facing the high-temperature side and a glass cloth surface facing the low-temperature side.

4. The multi-layer reflective high temperature piping insulation structure based on zoning design of heat transfer mechanisms as claimed in claim 1, wherein, The interval between the adjacent reflection layers (2) is not greater than 3mm.

5. The multi-layer reflective high temperature piping insulation structure based on zoning design of heat transfer mechanisms as claimed in claim 1, wherein, The high-temperature-resistant heat preservation cotton layer (1) and the high-temperature-resistant heat preservation cotton layer (2) adopt aluminum silicate needle punching blankets.

6. The multi-layer reflective high temperature piping insulation structure based on zoning design of heat transfer mechanisms as claimed in claim 1, wherein, The conventional heat preservation cotton layer adopts centrifugal glass wool.

7. The multi-layer reflective high temperature piping insulation structure based on zoning design of heat transfer mechanisms as claimed in claim 1, wherein, The outer side of the fourth heat preservation layer (4) is provided with a moisture-proof layer and a protective layer.

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