High vacuum multilayer composite adiabatic liquid hydrogen transfer pipeline

Abstract

The application discloses a high-vacuum multilayer composite heat-insulating liquid hydrogen conveying pipeline, which comprises an inner tube, an outer jacket tube is sleeved outside the inner tube, a relatively closed vacuum area is formed between the outer jacket tube and the inner tube, a first composite heat-insulating layer, a second composite heat-insulating layer and a third composite heat-insulating layer are sequentially sleeved outside the inner tube from inside to outside, a tube screen is arranged between the first composite heat-insulating layer and the second composite heat-insulating layer and between the second composite heat-insulating layer and the third composite heat-insulating layer, respectively, liquid nitrogen is filled in each cold tube in the tube screen between the first composite heat-insulating layer and the second composite heat-insulating layer, so that a liquid nitrogen cold screen is formed between the first composite heat-insulating layer and the second composite heat-insulating layer, cold nitrogen gas is filled in each cold tube in the tube screen between the second composite heat-insulating layer and the third composite heat-insulating layer, so that a cold nitrogen gas cold screen is formed between the second composite heat-insulating layer and the third composite heat-insulating layer, and a vacuum interlayer is formed between the third composite heat-insulating layer and the outer jacket tube. The application has the advantage of reducing liquid hydrogen vaporization.

Description

Technical Field

[0001] This invention relates to the field of liquid hydrogen transport equipment technology, specifically to a high-vacuum multi-layer composite insulated liquid hydrogen transport pipeline. Background Technology

[0002] The structure of traditional high-vacuum insulated liquid hydrogen transport pipelines, such as Figure 1 As shown, the system includes an inner tube 111, with an outer jacket 112 surrounding the inner tube 111. A relatively closed vacuum zone is formed between the outer jacket 112 and the inner tube 111. A composite insulation layer 113 is installed within this vacuum zone, surrounding the inner tube 111. A vacuum interlayer 114 is formed between the composite insulation layer 113 and the outer jacket 112. When liquid hydrogen is transported through the liquid hydrogen pipeline, the temperature of the liquid hydrogen flowing through the inner tube is -253℃, while the outside of the outer jacket is at ambient temperature, resulting in a temperature difference of approximately 273℃ between the outer jacket and the inner tube. Heat transfer inevitably occurs. When external heat is transferred to the inner tube through the outer jacket, the liquid hydrogen inside the inner tube partially vaporizes upon heating. The vaporized hydrogen, due to overpressure or failure to meet the requirements for liquid hydrogen use, must be discharged. Traditional liquid hydrogen transport pipelines suffer from severe heat leakage due to small vacuum jackets and limited insulation efficiency of composite insulation layers. This results in a large amount of liquid hydrogen evaporating into gaseous hydrogen during transport, leading to significant waste. Summary of the Invention

[0003] The purpose of this invention is to provide a high-vacuum multilayer composite insulated liquid hydrogen transport pipeline that can reduce liquid hydrogen vaporization.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: a high-vacuum multi-layer composite insulated liquid hydrogen transport pipeline, comprising an inner tube, an outer jacketed tube sleeved outside the inner tube, forming a relatively closed vacuum zone between the outer jacketed tube and the inner tube, wherein a first composite insulation layer, a second composite insulation layer and a third composite insulation layer are disposed in the vacuum zone, the first composite insulation layer, the second composite insulation layer and the third composite insulation layer being sequentially sleeved outside the inner tube from the inside to the outside along the radial direction of the transport pipeline, and cold pipes are respectively disposed between the first composite insulation layer and the second composite insulation layer, and between the second composite insulation layer and the third composite insulation layer. The tube screen is fitted over the inner tube. Liquid nitrogen is passed through each cold tube in the tube screen located between the first composite insulation layer and the second composite insulation layer to form a liquid nitrogen cold screen between the first composite insulation layer and the second composite insulation layer to block external heat from entering the inner tube. Cold nitrogen is passed through each cold tube in the tube screen located between the second composite insulation layer and the third composite insulation layer to form a cold nitrogen cold screen between the second composite insulation layer and the third composite insulation layer to block external heat from entering the inner tube. A gap is left between the third composite insulation layer and the outer jacket tube to form a vacuum jacket between the third composite insulation layer and the outer jacket tube.

[0005] Furthermore, in the aforementioned high-vacuum multi-layer composite insulated liquid hydrogen transport pipeline, the tube screen disposed between the first composite insulation layer and the second composite insulation layer adopts any one of three tube screen structures: a spiral tube screen structure, a pipe-type tube screen structure, and a serpentine tube screen structure; and the tube screen disposed between the second composite insulation layer and the third composite insulation layer adopts any one of three tube screen structures: a spiral tube screen structure, a pipe-type tube screen structure, and a serpentine tube screen structure.

[0006] Furthermore, in the aforementioned high-vacuum multilayer composite insulated liquid hydrogen transport pipeline, the spiral tube screen structure includes several independent spiral cold tubes, each spiral cold tube being coiled in parallel around the outside of the inner tube to form the spiral tube screen structure.

[0007] Furthermore, the aforementioned high-vacuum multi-layer composite insulated liquid hydrogen transport pipeline includes a pipe-type screen structure comprising: an inlet annular cold pipe with an inlet, an outlet annular cold pipe with an outlet, and several straight cold pipes. Each straight cold pipe is evenly arranged around the periphery of the transport pipeline outside the inner pipe. The same side end of each straight cold pipe is simultaneously connected to the inlet annular cold pipe, and the other side end of each straight cold pipe is simultaneously connected to the outlet annular cold pipe, thus forming a pipe-type screen structure.

[0008] Furthermore, in the aforementioned high-vacuum multi-layer composite insulated liquid hydrogen transport pipeline, the serpentine tube screen structure includes: several direct cooling pipes and several connecting elbows. Each direct cooling pipe is evenly arranged around the periphery of the transport pipeline outside the inner pipe, and the direct cooling pipes are connected end to end by connecting elbows to form the serpentine tube screen structure.

[0009] Furthermore, in the aforementioned high-vacuum multilayer composite insulated liquid hydrogen transport pipeline, a thin copper tube is sleeved outside the first composite insulation layer, and the thin copper tube is located between the first composite insulation layer and the liquid nitrogen cooling screen.

[0010] Through the implementation of the above technical solutions, the beneficial effects of the present invention are: (1) Active intervention insulation is carried out by using liquid nitrogen cold screen and cold nitrogen gas cold screen. The latent heat of vaporization of cheap liquid nitrogen (the price of liquid nitrogen is much lower than the price of liquid hydrogen) blocks most of the heat entering the inner tube, thereby reducing the vaporization of liquid hydrogen in the inner tube and improving economic efficiency; (2) The setting of liquid hydrogen cold screen and cold nitrogen gas cold screen reduces the temperature gradient in the vacuum zone between the inner tube and the outer jacket tube, improves the insulation performance, further reduces the vaporization of liquid hydrogen in the inner tube, and improves economic efficiency; (3) A thin steel pipe is added between the liquid nitrogen cold screen and the first composite insulation layer, making the heat exchange more uniform, further reducing the vaporization of liquid hydrogen in the inner tube and improving economic efficiency. Attached Figure Description

[0011] Figure 1This is a schematic diagram of the high-vacuum insulated liquid hydrogen transport pipeline described in the background art.

[0012] Figure 2 This is a schematic diagram of the structure of a high-vacuum multilayer composite insulated liquid hydrogen transport pipeline according to the present invention.

[0013] Figure 3 for Figure 2 An enlarged schematic diagram of the H portion shown.

[0014] Figure 4 This is a schematic diagram of a spiral tube screen structure.

[0015] Figure 5 This is a schematic diagram of a pipe-type screen structure.

[0016] Figure 6 for Figure 5 The diagram shows a structural schematic of the AA cross section.

[0017] Figure 7 This is a schematic diagram of the unfolded serpentine tube screen structure. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0019] like Figure 2 , Figure 3 As shown, a high-vacuum multi-layer composite insulated liquid hydrogen transport pipeline includes an inner pipe 1, with an outer jacket pipe 2 sleeved around the inner pipe 1. A relatively closed vacuum zone is formed between the outer jacket pipe 2 and the inner pipe 1. A first composite insulation layer 3, a second composite insulation layer 4, and a third composite insulation layer 5 are disposed within the vacuum zone. These layers are sequentially sleeved around the inner pipe 1 radially from the inside to the outside. Cold pipes formed by cooling are respectively disposed between the first composite insulation layer 3 and the second composite insulation layer 4, and between the second composite insulation layer 4 and the third composite insulation layer 5, and are sleeved around the inner pipe. The tube screen is located between the first composite insulation layer 3 and the second composite insulation layer 4. Each cold pipe in the tube screen is filled with liquid nitrogen to form a liquid nitrogen cold screen 6 between the first composite insulation layer and the second composite insulation layer to block external heat from entering the inner tube 1. Each cold pipe in the tube screen is located between the second composite insulation layer 4 and the third composite insulation layer 5 is filled with cold nitrogen to form a cold nitrogen cold screen 7 between the second composite insulation layer 4 and the third composite insulation layer 5 to block external heat from entering the inner tube 1. A gap is left between the third composite insulation layer 5 and the outer jacket tube 2 to form a vacuum jacket 8 between the third composite insulation layer 5 and the outer jacket tube 2.

[0020] In this embodiment, the tube screen disposed between the first composite insulation layer 3 and the second composite insulation layer 4 adopts any one of three tube screen structures: a spiral tube screen structure, a pipe-type tube screen structure, and a serpentine tube screen structure. The tube screen disposed between the second composite insulation layer 4 and the third composite insulation layer 5 adopts any one of three tube screen structures: a spiral tube screen structure, a pipe-type tube screen structure, and a serpentine tube screen structure.

[0021] In this embodiment, as Figure 4 As shown, the spiral tube screen structure includes: several independent spiral cooling tubes 9, each spiral cooling tube 9 coiled in parallel around the outside of the inner tube 1 to form a spiral tube screen structure; in this embodiment, as Figure 5 , Figure 6 As shown, the pipe-type cooling screen structure includes: an inlet annular cooling pipe 10 with an inlet, an outlet annular cooling pipe 11 with an outlet, and several straight cooling pipes 12. Each straight cooling pipe 12 is evenly arranged around the outer side of the inner pipe 1 along the circumference of the conveying pipe. The same-side end of each straight cooling pipe 12 is simultaneously connected to the inlet annular cooling pipe 10, and the other-side end of each straight cooling pipe 12 is simultaneously connected to the outlet annular cooling pipe 11, forming a pipe-type cooling screen structure. In this embodiment, as... Figure 7 As shown, the serpentine tube screen structure includes: several straight cooling pipes 12 and several connecting elbows 13. Each straight cooling pipe 12 is evenly arranged around the periphery of the conveying pipeline outside the inner pipe 1. Each straight cooling pipe 12 is connected end to end by the connecting elbows 13 to form a serpentine tube screen structure.

[0022] In this embodiment, a thin copper tube 14 is sleeved on the outside of the first composite insulation layer 3. The thin copper tube 14 is located between the first composite insulation layer 3 and the liquid nitrogen cooling screen 6. The thin copper tube 14 makes the temperature distribution on the outer surface of the inner tube 1 after the liquid nitrogen condenses more uniform.

[0023] In use, liquid hydrogen at -253°C flows inside the inner tube of the high-vacuum multi-layer composite insulated liquid hydrogen transport pipeline. During the transport of liquid hydrogen, the vacuum zone between the inner and outer tubes, and the vacuum interlayer 8 formed between the third composite insulation layer 5 and the outer jacket 2, are used to reduce heat convection and conduction, thereby reducing heat leakage. The first composite insulation layer 3, the second composite insulation layer 4, and the third composite insulation layer 5 are used to reduce heat radiation and conduction, thereby reducing heat leakage. At the same time, liquid nitrogen cold shields and cold nitrogen gas cold shields are used for active intervention insulation. The latent heat of vaporization of liquid nitrogen blocks most of the heat entering the inner tube, thereby reducing the vaporization of liquid hydrogen in the inner tube and improving economic efficiency.

[0024] The advantages of this invention are: (1) Active intervention insulation is achieved by using liquid nitrogen cold screen and cold nitrogen gas cold screen. The latent heat of vaporization of cheap liquid nitrogen (the price of liquid nitrogen is much lower than that of liquid hydrogen) blocks most of the heat entering the inner tube, thereby reducing the vaporization of liquid hydrogen in the inner tube and improving economic efficiency; (2) The setting of liquid hydrogen cold screen and cold nitrogen gas cold screen reduces the temperature gradient in the vacuum zone between the inner tube and the outer jacket tube, improves the insulation performance, further reduces the vaporization of liquid hydrogen in the inner tube, and improves economic efficiency; (3) A thin steel pipe is added between the liquid nitrogen cold screen and the first composite insulation layer, which makes the heat exchange more uniform, further reduces the vaporization of liquid hydrogen in the inner tube, and improves economic efficiency.

[0025] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any modifications or equivalent changes made based on the technical essence of the present invention shall still fall within the scope of protection claimed by the present invention.

Claims

1. A high-vacuum multi-layer composite insulated liquid hydrogen transport pipeline, characterized in that: The system includes an inner tube, to which an outer jacketed tube is fitted. A relatively closed vacuum zone is formed between the outer jacketed tube and the inner tube. Within this vacuum zone, a first composite insulation layer, a second composite insulation layer, and a third composite insulation layer are installed. These three composite insulation layers are sequentially fitted around the inner tube from the inside out along the radial direction of the conveying pipeline. Between the first and second composite insulation layers, and between the second and third composite insulation layers, pipe screens formed by cold pipes are respectively installed outside the inner tube. Liquid nitrogen is circulated through each cold pipe in the tube screen between the first composite insulation layer and the second composite insulation layer to form a liquid nitrogen cold screen between the first composite insulation layer and the second composite insulation layer to block external heat from entering the inner tube. Cold nitrogen gas is circulated through each cold pipe in the tube screen between the second composite insulation layer and the third composite insulation layer to form a cold nitrogen gas cold screen between the second composite insulation layer and the third composite insulation layer to block external heat from entering the inner tube. A gap is left between the third composite insulation layer and the outer jacket tube to form a vacuum jacket between the third composite insulation layer and the outer jacket tube.

2. The high-vacuum multi-layer composite insulated liquid hydrogen transport pipeline according to claim 1, characterized in that: The tube shield installed between the first composite insulation layer and the second composite insulation layer adopts any one of the three tube shield structures: spiral tube shield structure, pipe-lined tube shield structure, and serpentine tube shield structure. The tube shield installed between the second composite insulation layer and the third composite insulation layer adopts any one of the three tube shield structures: spiral tube shield structure, pipe-lined tube shield structure, and serpentine tube shield structure.

3. The high-vacuum multi-layer composite insulated liquid hydrogen transport pipeline according to claim 2, characterized in that: The spiral tube screen structure includes several independent spiral cooling tubes, which are coiled in parallel around the outside of the inner tube to form the spiral tube screen structure.

4. The high-vacuum multi-layer composite insulated liquid hydrogen transport pipeline according to claim 2, characterized in that: The pipe-type tube screen structure includes: an inlet annular cold pipe with an inlet, an outlet annular cold pipe with an outlet, and several straight cold pipes. Each straight cold pipe is evenly arranged around the outside of the inner pipe along the circumference of the conveying pipeline. The same side end of each straight cold pipe is simultaneously connected to the inlet annular cold pipe, and the other side end of each straight cold pipe is simultaneously connected to the outlet annular cold pipe, forming a pipe-type tube screen structure.

5. A high-vacuum multi-layer composite insulated liquid hydrogen transport pipeline according to claim 2, characterized in that: The serpentine tube screen structure includes: several straight cooling pipes and several connecting elbows. Each straight cooling pipe is evenly arranged around the periphery of the conveying pipeline outside the inner pipe. The straight cooling pipes are connected end to end by connecting elbows to form a serpentine tube screen structure.

6. A high-vacuum multi-layer composite insulated liquid hydrogen transport pipeline according to claim 1, 2, 3, 4, or 5, characterized in that: A thin copper tube is fitted over the outside of the first composite insulation layer, and the thin copper tube is located between the first composite insulation layer and the liquid nitrogen cooling screen.

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