High-vacuum double-layer heat insulation pipe

Abstract

The invention relates to the technical field of heat insulation pipes, and provides a high-vacuum double-layer heat insulation pipe in order to solve the problems that in an existing heat insulation pipe, a rigid double-layer pipe is insufficient in reliability, and a flexible heat insulation pipe is weak in pipeline pressure bearing capacity and insufficient in overall uniformity and stability, and the high-vacuum double-layer heat insulation pipe comprises a hard pipe section and a flexible pipe section. The end of the hard pipe section and the end of the flexible pipe section are connected in a sealed mode through a sealing cover. The center of the outer end of the sealing cover communicates with an end connector used for pipeline connection. The hard pipe section sequentially comprises an outer pipe, a first vacuum layer, a first ceramic heat insulation layer, a first anti-radiation layer, a first woven layer and a first metal corrugated pipe from outside to inside. The flexible pipe section sequentially comprises a second braid layer, a second metal corrugated pipe, a second ceramic heat insulation layer, a second anti-radiation layer, a third braid layer and a third metal corrugated pipe from outside to inside. The heat-insulating material has efficient heat-insulating performance, mechanical strength and flexibility are combined, and the overall stability is enhanced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heat insulation pipe, in particular to a high-vacuum double-layer heat insulation pipe. BACKGROUND

[0002] Heat insulation pipe (also known as heat preservation pipe and heat insulation pipe) is a kind of special pipe used to reduce heat exchange between fluid in the pipe and the external environment, and is widely used in energy transportation, industrial process, building heating and other fields. The core function of high-efficiency heat insulation pipe is to maximize the heat exchange between the internal fluid of the pipeline and the external environment, to ensure that the medium maintains stable phase and temperature during transportation, and to ensure the safe, reliable and economic operation of the system.

[0003] At present, the existing heat insulation pipe is mainly divided into rigid structure and flexible structure, and they all have technical limitations: 1. The traditional rigid double-layer pipe can provide a stable vacuum cavity, but its structure does not have flexible compensation ability, and under the action of thermal expansion and contraction, mechanical vibration or installation stress, it is easy to cause sealing failure, vacuum drop, and even pipeline rupture, and the reliability is insufficient; 2. The flexible heat insulation pipe mostly uses single-layer metal corrugated pipe as the core channel, when the pipeline bears internal pressure or external pressure, the pipeline will deform radially, which will damage its integrity and significantly deteriorate the heat insulation performance; 3. The internal heat insulation layer and the corrugated pipe, as well as the functional layers, may be loose, displaced or collapsed under long-term use and vibration environment, which will cause uneven distribution of the heat insulation layer and local hot spots or cold spots, affecting the uniformity and stability of the overall performance. SUMMARY

[0004] The present application provides a high-vacuum double-layer heat insulation pipe to solve the problems of insufficient reliability of rigid double-layer pipe, weak pressure-bearing capacity of flexible heat insulation pipe and insufficient uniformity and stability of the whole.

[0005] To solve the above technical problems, the technical scheme provided by the present application is as follows: a high-vacuum double-layer heat insulation pipe, comprising a hard pipe section and a flexible pipe section, the end portions of the hard pipe section and the flexible pipe section are sealed and connected by a sealing cover, and the outer end center of the sealing cover is connected with an end for pipeline connection; The hard pipe section comprises, from outside to inside, an outer pipe, a first vacuum layer, a first ceramic heat insulation layer, a first anti-radiation layer, a first braided layer and a first metal corrugated pipe; the flexible pipe section comprises, from outside to inside, a second braided layer, a second metal corrugated pipe, a second ceramic heat insulation layer, a second anti-radiation layer, a third braided layer and a third metal corrugated pipe; The two end ports of the first metal bellows are fixed by welding and sealing to the end portions of the rigid pipe section, and the two end ports of the second metal bellows and the third metal bellows are fixed by welding and sealing to the end portions of the flexible pipe section. The first vacuum layer is radially supported and separated by an annular spacing bushing arranged between the inner wall of the outer pipe and the outer wall of the first ceramic thermal insulation layer, and the first ceramic thermal insulation layer and the first anti-radiation layer are fixed by a first binding member. The second ceramic thermal insulation layer and the second anti-radiation layer are fixed by a second binding member, and the third woven layer is tightly attached to the third metal bellows by its own tension.

[0006] Further, at least a portion of the outer pipe is in a bellows structure.

[0007] The bellows structure allows one end of the rigid pipe section to have a flexible installation.

[0008] Further, the outer pipe, the first woven layer, the second woven layer and the third woven layer are all made of stainless steel material.

[0009] Further, the first anti-radiation layer and the second anti-radiation layer are each composed of a plurality of layers of metal foils arranged alternately and stacked, and the first anti-radiation layer and the second anti-radiation layer are respectively wound in the form of a plurality of foils on the outer surfaces of the first anti-radiation layer and the second anti-radiation layer.

[0010] Further, the annular spacing bushing is made of ceramic, and the annular spacing bushing is uniformly spaced along the axial direction of the rigid pipe section.

[0011] Further, the first binding member and the second binding member are both stainless steel straps.

[0012] The advantages of the present application are: 1. Efficient thermal insulation performance: the vacuum layer effectively eliminates gas convection and conduction, the ceramic layer blocks solid heat conduction, and the multi-layer aluminum foil anti-radiation layer reflects radiant heat, together forming an extremely low heat conduction path; 2. Combination of mechanical strength and flexibility: the pressure-bearing and sealing layers of the rigid pipe section and the flexible pipe section both use metal bellows, which not only withstands the internal and external pressure difference, but also becomes the key component for realizing bending and displacement of the entire pipeline due to its flexible characteristics; 3. Enhanced overall stability: the stainless steel woven layer wrapped outside the bellows enhances the pressure resistance, impact resistance and mechanical damage resistance of the pipeline, preventing the bellows from excessive deformation or rupture under high pressure; the annular spacing bushing not only supports the vacuum layer, but also prevents the shell from collapsing due to external pressure or vacuum negative pressure, and its ceramic material itself is also an excellent thermal insulator, reducing the thermal bridge effect. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is a schematic diagram of a hard pipe segment structure of the present application.

[0014] Figure 2 is a schematic diagram of a flexible pipe segment structure of the present application.

[0015] Figure 3 is a half sectional view of a hard pipe segment of the present application.

[0016] Figure 4 is a half sectional view of a flexible pipe segment of the present application.

[0017] As shown in the figure: 1, hard pipe segment; 2, flexible pipe segment; 3, sealing cover; 4, end connection; 10, outer pipe; 11, first vacuum layer; 12, first ceramic thermal insulation layer; 13, first anti-radiation layer; 14, first braided layer; 15, first metal bellows; 16, annular spacing bushing; 17, first binding member; 20, second braided layer; 21, second metal bellows; 22, second ceramic thermal insulation layer; 23, second anti-radiation layer; 24, third braided layer; 25, third metal bellows; 26, second binding member. DETAILED DESCRIPTION

[0018] The present application will be further described in detail below with reference to the accompanying drawings.

[0019] With reference to the accompanying drawings Figures 1-4 A high-vacuum double-layer thermal insulation pipe comprises a hard pipe segment 1 and a flexible pipe segment 2, the end portions of the hard pipe segment 1 and the flexible pipe segment 2 are sealed by a sealing cover 3, a through hole is formed in the center of the outer end of the sealing cover 3, and an end connection 4 for connecting with an external pipeline or equipment is communicated with the through hole, the end connection 4 is preferably a standard flange interface or a threaded interface, facilitating installation.

[0020] The hard pipe segment 1 comprises, from outside to inside, in sequence: The outer pipe 10 is a pressure-bearing and protective structure of the outermost layer of the pipe segment, is made of a stainless steel seamless pipe, and at least a portion of the outer pipe 10 can be made into a bellows structure, so that the originally “hard” pipe segment has a certain flexibility at one end, can better adapt to the centering error and slight displacement change of the pipeline system, and reduces the installation difficulty; The first vacuum layer 11 is a high-vacuum sealed cavity between the inner wall of the outer pipe 10 and the outer wall of the first ceramic thermal insulation layer 12, and is used to eliminate gas molecule conduction and convection; The first ceramic thermal insulation layer 12 is made of an alumina or zirconia ceramic fiber felt, is wrapped into a cylindrical shape, and mainly functions to block heat conduction; The first anti-radiation layer 13 is arranged in close contact with the inner wall of the first ceramic thermal insulation layer 12, is composed of a plurality of layers of alternately stacked metal foils, and is wrapped in the form of a plurality of foil layers, and mainly functions to reflect radiant heat and reduce radiation heat transfer; The first braided layer 14 is a mesh sleeve braided by stainless steel wires, tightly covering the outside of the first anti-radiation layer 13, and plays a role of reinforcing and binding the internal multi-layer structure; The first metal bellows 15 is made of corrosion-resistant stainless steel, and is used for conveying fluid medium, and the two end ports are fixed and sealed with the end portions of the rigid pipe section 1 by welding, so as to ensure the absolute air tightness of the core flow channel.

[0021] The flexible pipe section 2 comprises, from outside to inside, in sequence: The second braided layer 20 is the outermost layer of the flexible pipe section 2, and is braided by stainless steel wires to provide main mechanical strength and anti-abrasion protection; The second metal bellows 21 is located inside the second braided layer 20, and is a corresponding pressure-bearing and sealing layer thereof; The second ceramic thermal insulation layer 22 has the same material and function as the first ceramic thermal insulation layer 12; The second anti-radiation layer 23 has the same material and function as the first anti-radiation layer 13; The third braided layer 24 has the same material and function as the first braided layer 14, and the third braided layer 24 has a certain pre-tightening force when braided and manufactured, and is naturally attached to the outer wall of the third metal bellows 25 through its own tension; The third metal bellows 25 is the core channel of the innermost layer of the flexible pipe section 2, and is used for conveying fluid medium, and the two end ports are fixed and sealed with the end portions of the rigid pipe section 1 by welding.

[0022] The first vacuum layer 11 is internally provided with annular spacing bushings 16 made of ceramic, the outer diameter of the annular spacing bushings 16 is in contact with the inner wall of the outer pipe 10, and the inner diameter of the annular spacing bushings 16 is in contact with the outer wall of the first ceramic thermal insulation layer 12, so as to support and separate the two in the radial direction, prevent the outer atmospheric pressure from crushing the outer layer structure, and a plurality of annular spacing bushings 16 are uniformly distributed at a certain interval along the axial direction of the rigid pipe section 1.

[0023] The first ceramic thermal insulation layer 12 and the first anti-radiation layer 13 are fixed by the first binding member 17, and similarly, the second ceramic thermal insulation layer 22 and the second anti-radiation layer 23 are fixed by the second binding member 26, so as to prevent the interlayer structure from loosening or displacing under vibration or bending.

[0024] The above describes the present application and its embodiments, which are not limited, and the drawings only show one of the embodiments of the present application, and the actual structure is not limited thereto. In general, if a person skilled in the art is inspired thereby, without departing from the purpose of the present application, without creative design, similar structure and embodiments of the technical solution can be designed, which shall belong to the protection scope of the present application.

Claims

1. A high vacuum double-layer insulation pipe, characterized by: The pipe comprises a rigid pipe section (1) and a flexible pipe section (2), the end of the rigid pipe section (1) and the end of the flexible pipe section (2) are connected by a sealing cover (3), and the outer end of the sealing cover (3) is connected with a terminal (4) for pipeline connection; The rigid pipe section (1) comprises, from outside to inside, an outer pipe (10), a first vacuum layer (11), a first ceramic thermal insulation layer (12), a first anti-radiation layer (13), a first braided layer (14), and a first metal bellows (15); the flexible pipe section (2) comprises, from outside to inside, a second braided layer (20), a second metal bellows (21), a second ceramic thermal insulation layer (22), a second anti-radiation layer (23), a third braided layer (24), and a third metal bellows (25); The two end ports of the first metal bellows (15) are fixedly connected with the end of the rigid pipe section (1) by welding, and the two end ports of the second metal bellows (21) and the third metal bellows (25) are fixedly connected with the end of the flexible pipe section (2) by welding; The first vacuum layer (11) is radially supported and separated by an annular spacing bushing (16) arranged between the inner wall of the outer pipe (10) and the outer wall of the first ceramic thermal insulation layer (12), and the first ceramic thermal insulation layer (12) and the first anti-radiation layer (13) are fixed by a first binding member (17); The second ceramic thermal insulation layer (22) and the second anti-radiation layer (23) are fixed by a second binding member (26), and the third braided layer (24) is tightly attached to the third metal bellows (25) by its own tension.

2. The high vacuum double-layer insulation pipe according to claim 1, characterized in that: At least a portion of the outer pipe (10) is in a bellows structure.

3. The high vacuum double-layer insulation pipe according to claim 1, characterized in that: The outer pipe (10), the first braided layer (14), the second braided layer (20), and the third braided layer (24) are all made of stainless steel material.

4. The high vacuum double-layer insulation pipe according to claim 1, characterized in that: The first anti-radiation layer (13) and the second anti-radiation layer (23) are both composed of multiple layers of alternately stacked metal foils, and the first anti-radiation layer (13) and the second anti-radiation layer (23) are respectively wound in the form of multiple foil sheets on the outer surfaces of the first anti-radiation layer (13) and the second anti-radiation layer (23).

5. The high vacuum double-layer insulation pipe according to claim 1, characterized in that: The annular spacing bushing (16) is made of ceramic, and the annular spacing bushing (16) is uniformly and spacedly distributed along the axial direction of the rigid pipe section (1).

6. The high vacuum double-layer insulation pipe according to claim 1, characterized in that: The first binding member (17) and the second binding member (26) are both stainless steel straps.

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