Liquid hydrogen storage tank

Abstract

The invention provides a liquid hydrogen storage tank. The liquid hydrogen storage tank is sequentially provided with an inner tank, a variable-density heat insulation layer, a vacuum interlayer, an outer tank and an aerogel layer from inside to outside. The variable-density heat-insulating layer is at least provided with three first heat-insulating layers with different densities, and the densities of the variable-density heat-insulating layer are gradually increased from inside to outside; the first heat insulation layer is sequentially provided with a reflecting layer and a plurality of spacing layers. According to the liquid hydrogen storage tank, through the combined design of the variable-density heat insulation layer, the vacuum interlayer and the aerogel layer, heat transfer is effectively isolated, and the safety of the liquid hydrogen storage tank is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of liquid hydrogen storage tank equipment and relates to a liquid hydrogen storage tank. Background Art

[0002] As an emerging energy source, hydrogen has the advantages of high efficiency, cleanliness, pollution-free and sustainability. With the rapid development of my country's economy and the continuous improvement of environmental governance requirements, hydrogen is one of the most promising clean energy sources.

[0003] At present, the main methods of hydrogen storage are high-pressure gaseous hydrogen storage and low-temperature liquid hydrogen storage. Among them, liquid hydrogen, as the liquefied state of hydrogen, has long been used as fuel for aerospace power systems and is widely used in aerospace. With the development of production technology at home and abroad, the use of liquid hydrogen is increasingly approaching the civilian market. Low-temperature liquid hydrogen storage is a deep-cold hydrogen storage technology. The hydrogen is deep-cooled to below about -253°C to turn it into liquid hydrogen, and then stored in an insulated container. The advantage of low-temperature liquid hydrogen storage is that the density of liquid hydrogen reaches 70.85kg / m 3 , which is approximately 850 times the density of hydrogen under standard conditions. This gives it the highest hydrogen storage density, making it suitable for long-distance transportation, such as sea and long-distance trucking. Shipping and long-distance trucking of liquid hydrogen are crucial components of the hydrogen energy industry chain, enabling cross-sector and cross-regional distribution of hydrogen energy. Furthermore, liquid hydrogen storage tanks can be used for hydrogen storage at hydrogen users.

[0004] However, liquid hydrogen has an extremely low boiling point and a significant temperature difference from the ambient temperature, making it highly susceptible to vaporization. This places very high demands on the thermal insulation of hydrogen storage containers. Poor tank insulation can lead to vaporization of liquid hydrogen, increasing tank pressure and forcing pressure relief, which in turn results in hydrogen loss. Furthermore, hydrogen is highly flammable and explosive, placing even higher demands on the thermal insulation and safety performance of liquid hydrogen storage tanks.

[0005] In summary, since liquid hydrogen storage tanks are key equipment in the field of hydrogen energy storage and transportation, there is an urgent need to provide a liquid hydrogen storage tank that is intrinsically safe and has excellent insulation. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a liquid hydrogen storage tank, which effectively blocks the heat transfer and improves the safety of the liquid hydrogen storage tank through the combined design of a variable density insulation layer, a vacuum interlayer and an aerogel layer.

[0007] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0008] The present invention provides a liquid hydrogen storage tank, which is provided with an inner tank, a variable density insulation layer, a vacuum interlayer, an outer tank and an aerogel layer in sequence from the inside to the outside;

[0009] The variable density heat insulation layer is provided with at least three first heat insulation layers of different densities, and the density of the variable density heat insulation layer is distributed in an increasing manner from the inside to the outside;

[0010] The first heat-insulating layer is sequentially provided with a reflective layer and a plurality of spacer layers.

[0011] In the present invention, the inner tank is used to store liquid hydrogen, the variable density insulation layer is provided on the outer surface of the inner tank, and the aerogel layer is provided on the outer surface of the outer tank.

[0012] The liquid hydrogen storage tank provided by the present invention comprises an inner tank, a variable density insulation layer, a vacuum interlayer, an outer tank and an aerogel layer, which are sequentially arranged from the inside to the outside. The density of the reflective layer of the variable density insulation layer is distributed in an increasing manner from the inside to the outside, which effectively reduces heat transfer, meets insulation requirements, and improves the safety of the liquid hydrogen storage tank.

[0013] It should be noted that the enclosed cavity formed between the inner tank and the outer tank is vacuumed to make it a vacuum interlayer (high vacuum insulation layer), and a variable density insulation layer with an increasing reflective layer density is provided on the outer wall surface of the inner tank. The low-density insulation layer is close to the outer wall of the inner tank, and the high-density insulation layer is far away from the outer wall of the inner tank. It not only reduces the thermal conductivity of the solid, but also helps to reduce radiation heat transfer. Through the coordinated design of the above structure, the amount of spacer material is reduced, which is also conducive to vacuuming, reducing the outgassing rate, reducing costs, and improving the cold preservation performance of the liquid hydrogen storage tank.

[0014] It should also be noted that the insulation layer of the outer tank body is an aerogel layer, which has a very low thermal conductivity, further blocking the transmission of external heat. It also has high strength and excellent anti-collision performance. It is a non-combustible material, which improves the safety and protection performance of the storage tank.

[0015] As a preferred technical solution of the present invention, the total number of layers of the variable density insulation layer is 40-95 layers, for example, it can be 45 layers, 60 layers, 65 layers, 70 layers, 75 layers, 80 layers, 85 layers or 90 layers, etc., but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0016] It should be noted that by controlling the total number of layers of the variable-density insulation layer, the thermal insulation effect can be effectively exerted without increasing the mass of the storage tank.

[0017] Preferably, the apparent thermal conductivity of the variable density insulation layer is ≤1×10 -4 W / (m·K), for example, it can be 9×10 -5 W / (m·K), 8×10 -5 W / (m·K), 7×10 -5 W / (m·K), 6×10 -5 W / (m·K) or 5×10 -5W / (m·K), etc., but not limited to the listed values. Other values not listed in the numerical range are also applicable, preferably ≤7×10 -5 W / (m·K).

[0018] In the present invention, the apparent thermal conductivity is obtained by calculation.

[0019] As a preferred technical solution of the present invention, the first insulation layer is arranged in sequence along the outer wall of the inner tank. When the number of layers of the first insulation layer is 15%-35% of the total number of layers of the variable density insulation layer, the number of the spacing layers in the first insulation layer is at least 2; the number of the spacing layers in the remaining part of the first insulation layer is 1.

[0020] In the present invention, when the number of layers of the first insulation layer is 15%-35% of the total number of layers of the variable density insulation layer, for example, it can be 16%, 18%, 20%, 22%, 25%, 26%, 28%, 30% or 32%, etc., the number of spacing layers in the first insulation layer is at least 2, for example, it can be 3 layers, 4 layers, 5 layers, 6 layers, 7 layers, 8 layers, 10 layers or 12 layers, etc., but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0021] It should be noted that controlling the number of spacer layers in a specific low-temperature section and increasing the number of spacer layers between adjacent reflective layers to reduce the density of the first insulation layer is more conducive to reducing solid thermal conductivity; combined with controlling the number of spacer layers in a specific high-temperature section and reducing the number of spacer layers between adjacent reflective layers to increase the density of the first insulation layer, it is more conducive to blocking radiation heat transfer.

[0022] As a preferred technical solution of the present invention, a first insulation layer is arranged in sequence along the outer wall of the inner tank. When the number of layers of the first insulation layer is 15%-35% of the total number of layers of the variable density insulation layer, the number of spacing layers in the first insulation layer is 2-10; the number of spacing layers in the remaining part of the first insulation layer is 1.

[0023] As a preferred technical solution of the present invention, the material of the reflective layer includes aluminum foil and / or double-sided aluminum-plated polyester film.

[0024] Preferably, the thickness of the reflective layer is 0.004 to 0.025 mm, for example, it can be 0.005 mm, 0.008 mm, 0.01 mm, 0.012 mm, 0.015 mm, 0.018 mm, 0.02 mm, 0.022 mm or 0.024 mm, and the reflectivity is 0.970 to 0.998, for example, it can be 0.975, 0.980, 0.985, 0.990 or 0.995, but is not limited to the listed values, and other values not listed within the numerical range are also applicable.

[0025] In the present invention, a highly reflective, extremely thin double-sided aluminized polyester film and / or aluminum foil is used as the reflective layer, which can effectively block the transfer of radiant heat.

[0026] As a preferred technical solution of the present invention, the material of the spacer layer includes glass fiber paper and / or polyester mesh.

[0027] Preferably, the thickness of the spacer layer is 0.01 to 0.08 mm, for example, 0.02 mm, 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm or 0.07 mm, etc., but is not limited to the listed values, and other values not listed within the numerical range are also applicable.

[0028] In the present invention, thin glass fiber paper and / or polyester is used as the spacer layer to effectively prevent heat from being transferred inside the insulation layer by heat conduction, thereby improving the insulation performance of the first insulation layer.

[0029] As a preferred technical solution of the present invention, the vacuum degree of the vacuum interlayer is ≤10 -3 Pa.

[0030] In the present invention, since there is no air in the vacuum interlayer, most of the convection heat transfer can be blocked and the construction cost of the storage tank can be reduced.

[0031] As a preferred technical solution of the present invention, the thickness of the aerogel layer is 5 to 50 mm, for example, it can be 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm or 45 mm, but is not limited to the listed values. Other values not listed within the numerical range are also applicable.

[0032] It should be noted that by controlling the thickness range of the aerogel layer, if the thickness of the aerogel layer is too thick, the insulation effect will be limited, and the material cost and installation cost will increase instead; if the thickness of the aerogel layer is too thin, the insulation effect will be poor and the safety protection will be insufficient.

[0033] Preferably, the material of the aerogel layer includes calcium silicate-based aerogel.

[0034] In the present invention, the calcium silicate-based aerogel material used is a non-combustible material with a fire protection grade of A. It is porous and light, has high strength and good collision resistance, and provides a safety protection barrier for the storage tank with both flame retardant and collision resistance functions.

[0035] As a preferred technical solution of the present invention, the mass ratio of silicon to calcium in the calcium silicate-based aerogel is (0.5-1.6):1, for example, it can be 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1 or 1.5:1, but is not limited to the listed values, and other values not listed within the numerical range are also applicable.

[0036] Preferably, the porosity of the calcium silicate-based aerogel is 75% to 99%, for example, it can be 76%, 78%, 80%, 82%, 84%, 85%, 86%, 88%, 90%, 92%, 94%, 95%, 96% or 98%, etc., but is not limited to the listed values, and other values not listed within the numerical range are also applicable.

[0037] Preferably, the thermal conductivity of the calcium silicate-based aerogel is 0.01 to 0.03 W / (m·K), for example, it can be 0.012 W / (m·K), 0.015 W / (m·K), 0.016 W / (m·K), 0.018 W / (m·K), 0.02 W / (m·K), 0.022 W / (m·K), 0.025 W / (m·K), 0.026 W / (m·K) or 0.028 W / (m·K), etc., but is not limited to the listed values, and other values not listed within the numerical range are also applicable.

[0038] Preferably, the density of the calcium silicate-based aerogel is 15 to 65 kg / m 3 , for example, it can be 20kg / m 3 , 25kg / m 3 、30kg / m 3 、35kg / m 3 , 40kg / m 3 , 45kg / m 3 , 50kg / m 3 , 55kg / m 3 or 60kg / m 3 The present invention is not limited to the listed values, and other values not listed in the numerical range are also applicable.

[0039] Preferably, the compressive strength of the calcium silicate-based aerogel is 10 to 40 MPa, for example, 15 MPa, 20 MPa, 25 MPa, 30 MPa or 35 MPa, but is not limited to the listed values, and other values not listed within the numerical range are also applicable.

[0040] As a preferred technical solution of the present invention, the shape of the liquid hydrogen storage tank includes cylindrical or spherical.

[0041] Preferably, the inner tank is made of stainless steel.

[0042] In the present invention, the material of the inner tank is preferably low-temperature resistant stainless steel.

[0043] Preferably, the outer tank is made of stainless steel or carbon steel.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] (1) The liquid hydrogen storage tank provided by the present invention is provided with a combination of an inner tank, a variable density insulation layer, a vacuum interlayer, an outer tank and an aerogel layer in sequence from the inside to the outside. The density of the variable density insulation layer is gradually increased from the inside to the outside, and the outermost layer has a high strength and non-flammable gas gel layer with excellent thermal insulation, which effectively reduces heat transfer, meets the insulation requirements, and improves the safety of the liquid hydrogen storage tank.

[0046] (2) The liquid hydrogen storage tank provided by the present invention has a closed cavity formed between the inner tank and the outer tank to form a vacuum interlayer by vacuuming, and a variable density insulation layer with a reflective layer density increasing on the outer wall surface of the inner tank is provided. The layer close to the outer wall of the inner tank is a low-density insulation layer, and the layer far from the outer wall of the inner tank is a high-density insulation layer, which not only reduces the thermal conductivity of the solid, but also is more conducive to reducing radiation heat transfer. Through the coordinated design of the above structure, the amount of spacer material used is reduced, which is conducive to vacuuming, reducing the degassing rate, reducing costs, and improving the cold preservation performance of the liquid hydrogen storage tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a structural schematic diagram of a liquid hydrogen storage tank provided by the present invention;

[0048] Figure 2 It is a schematic cross-sectional structural diagram of a liquid hydrogen storage tank provided by the present invention;

[0049] Among them, 100-liquid hydrogen storage tank, 1-inner tank, 2-variable density insulation layer, 3-vacuum interlayer, 4-outer tank, 5-aerogel layer. DETAILED DESCRIPTION

[0050] It should be understood that, in the description of the present invention, the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0051] It should be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "disposed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0052] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0053] A specific embodiment of the present invention provides a liquid hydrogen storage tank, the liquid hydrogen storage tank 100 (such as Figure 1 As shown in FIG, an inner tank 1, a variable density insulation layer 2, a vacuum interlayer 3, an outer tank 4 and an aerogel layer 5 are sequentially arranged from the inside to the outside (as shown in FIG. Figure 2 shown);

[0054] The variable density insulation layer 2 is provided with at least three first insulation layers of different densities, and the density of the variable density insulation layer is distributed in an increasing manner from the inside to the outside;

[0055] The first heat-insulating layer is sequentially provided with a reflective layer and a plurality of spacer layers.

[0056] Example 1

[0057] This embodiment provides a liquid hydrogen storage tank, which is provided with an inner tank, a variable density insulation layer, a vacuum interlayer, an outer tank and an aerogel layer in sequence from the inside to the outside;

[0058] The variable density heat insulation layer is provided with four first heat insulation layers of different densities, and the density of the variable density heat insulation layer is distributed in an increasing manner from the inside to the outside;

[0059] The total number of layers of the variable density thermal insulation layer is 60; among them, from the 1st to the 2nd layer, each first thermal insulation layer a is sequentially provided with 1 reflective layer and 4 spacer layers; from the 3rd to the 5th layer, each first thermal insulation layer b is sequentially provided with 1 reflective layer and 3 spacer layers; from the 6th to the 20th layer, each first thermal insulation layer c is sequentially provided with 1 reflective layer and 2 spacer layers; from the 21st to the 60th layer, each first thermal insulation layer d is sequentially provided with 1 reflective layer and 1 spacer layer;

[0060] The reflective layer is an aluminum foil with a thickness of 0.0065 mm and a reflectivity of 0.985; the spacer layer is a glass fiber paper with a thickness of 0.075 mm; the vacuum degree of the vacuum interlayer is 0.0005 Pa;

[0061] The aerogel layer is a calcium silicate-based aerogel with a thickness of 30 mm; the mass ratio of silicon to calcium in the calcium silicate-based aerogel is 1:1, the porosity is 80%, the thermal conductivity is 0.02 W / (m·K), and the density is 28 kg / m 3 , compressive strength is 30MPa;

[0062] The inner tank is made of austenitic stainless steel 304, and the outer tank is made of carbon steel Q345R.

[0063] In this embodiment, the apparent thermal conductivity of the variable density insulation layer is 4.1×10 -5 W / (m·K); By optimizing the structural design of liquid hydrogen storage tanks, not only is solid thermal conductivity effectively reduced, but radiation heat transfer is also significantly reduced, significantly improving tank safety. Furthermore, this design reduces the amount of spacer material used, facilitating vacuum extraction, reducing outgassing rates, and significantly reducing costs.

[0064] Example 2

[0065] This embodiment provides a liquid hydrogen storage tank, wherein the total number of variable density insulation layers is 60; except for the adjustment of the first to the tenth layers, each first insulation layer a is sequentially provided with one reflective layer and three spacer layers; each first insulation layer b is sequentially provided with one reflective layer and two spacer layers from the 11th to the 20th layers; and each first insulation layer c is sequentially provided with one reflective layer and one spacer layer from the 21st to the 60th layers.

[0066] The aerogel insulation layer is a calcium silicate-based aerogel with a thickness of 27 mm. The mass ratio of silicon to calcium in the calcium silicate-based aerogel is 1:0.85, the porosity is 76%, the thermal conductivity is 0.018 W / (m·K), and the density is 31 kg / m 3 , compressive strength is 33MPa;

[0067] Other conditions are the same as in Example 1.

[0068] In this embodiment, the apparent thermal conductivity of the variable density insulation layer is 4.2×10 -5 W / (m·K); By optimizing the structural design of liquid hydrogen storage tanks, not only is solid thermal conductivity effectively reduced, but radiation heat transfer is also significantly reduced, significantly improving tank safety. Furthermore, this design reduces the amount of spacer material used, facilitating vacuum extraction, reducing outgassing rates, and significantly reducing costs.

[0069] Comparative Example 1

[0070] This comparative example provides a liquid hydrogen storage tank, wherein the total number of variable density insulation layers is 60; except for the adjustment of the 1st to 20th layers, each first insulation layer a is sequentially provided with 1 reflective layer and 3 spacer layers; from the 21st to the 40th layers, each first insulation layer b is sequentially provided with 1 reflective layer and 2 spacer layers; from the 41st to the 60th layers, each first insulation layer c is sequentially provided with 1 reflective layer and 1 spacer layer;

[0071] Other conditions are the same as in Example 1.

[0072] In this comparative example, the apparent thermal conductivity of the variable density insulation layer is 4.08×10 -5 W / (m·K). Although further reductions in apparent thermal conductivity are beneficial for tank insulation, the significant increase in the amount of spacer layer not only increases costs but also increases the material outgassing rate, hindering both the coating process and vacuuming between material layers. Furthermore, excessive material outgassing rates can also affect or even shorten the vacuum life of the hydrogen storage tank's insulation interlayer.

[0073] Comparative Example 2

[0074] This comparative example provides a liquid hydrogen storage tank, which is the same as Example 1 except that the calcium silicate-based aerogel is replaced by silicon dioxide aerogel.

[0075] In this comparative example, if the outer tank surface is covered with silica aerogel, the silica aerogel has low compressive strength and poor anti-collision performance, and cannot effectively improve the safety protection performance of the storage tank. In addition, the cost of silica aerogel is high, which is not conducive to large-scale promotion and use.

[0076] The applicant declares that the above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the scope of protection and disclosure of the present invention.

Claims

1. A liquid hydrogen storage tank, characterized in that: The liquid hydrogen storage tank is provided with an inner tank, a variable density insulation layer, a vacuum interlayer, an outer tank and an aerogel layer in sequence from the inside to the outside; The variable density heat insulation layer is provided with at least three first heat insulation layers of different densities, and the density of the variable density heat insulation layer is distributed in an increasing manner from the inside to the outside; The first heat-insulating layer is sequentially provided with a reflective layer and a plurality of spacer layers.

2. The liquid hydrogen storage tank according to claim 1, characterized in that: The total number of layers of the variable density insulation layer is 40-95 layers; Preferably, the apparent thermal conductivity of the variable density insulation layer is ≤1×10 -4 W / (m·K), preferably ≤7×10 -5 W / (m·K).

3. The liquid hydrogen storage tank according to claim 1 or 2, characterized in that: The first insulation layer is arranged in sequence along the outer wall of the inner tank. When the number of the first insulation layer is 15%-35% of the total number of the variable density insulation layer, the number of the spacer layers in the first insulation layer is at least 2; the number of the spacer layers in the remaining part of the first insulation layer is 1.

4. The liquid hydrogen storage tank according to claim 3, characterized in that: The first insulation layer is arranged in sequence along the outer wall of the inner tank. When the number of the first insulation layer is 15%-35% of the total number of the variable density insulation layer, the number of the spacer layers in the first insulation layer is 2-10; the number of the spacer layers in the remaining part of the first insulation layer is 1.

5. The liquid hydrogen storage tank according to any one of claims 1 to 4, characterized in that: The material of the reflective layer includes aluminum foil and / or double-sided aluminum-coated polyester film; Preferably, the reflective layer has a thickness of 0.004-0.025 mm and a reflectivity of 0.970-0.

998.

6. The liquid hydrogen storage tank according to any one of claims 1 to 5, characterized in that: The material of the spacer layer includes glass fiber paper and / or polyester mesh; Preferably, the thickness of the spacer layer is 0.01-0.08 mm.

7. The liquid hydrogen storage tank according to any one of claims 1 to 6, characterized in that: The vacuum degree of the vacuum interlayer is ≤10 -3 Pa.

8. The liquid hydrogen storage tank according to any one of claims 1 to 7, characterized in that: The thickness of the aerogel layer is 5 to 50 mm; Preferably, the material of the aerogel layer includes calcium silicate-based aerogel.

9. The liquid hydrogen storage tank according to claim 8, characterized in that: The mass ratio of silicon to calcium in the calcium silicate-based aerogel is (0.5-1.6):1; Preferably, the porosity of the calcium silicate-based aerogel is 75% to 99%; Preferably, the thermal conductivity of the calcium silicate-based aerogel is 0.01 to 0.03 W / (m·K); Preferably, the density of the calcium silicate-based aerogel is 15 to 65 kg / m 3 ; Preferably, the compressive strength of the calcium silicate-based aerogel is 10 to 40 MPa.

10. The liquid hydrogen storage tank according to any one of claims 1 to 9, characterized in that: The shape of the liquid hydrogen storage tank includes cylindrical or spherical; Preferably, the material of the inner tank includes stainless steel; Preferably, the outer tank is made of stainless steel or carbon steel.

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