Low-loss liquid hydrogen storage device using directed radiation refrigeration

Abstract

The application discloses a low-loss liquid hydrogen storage device using directional radiation refrigeration technology, which comprises a storage tank for storing liquid hydrogen, a cladding member wrapped outside the storage tank, a heat insulation member wrapped outside the cladding member and capable of reducing heat transfer, a radiation refrigeration film wrapped outside the heat insulation member and capable of reflecting radiation rays, and a reflecting member arranged on one side of the storage tank and capable of reflecting radiation rays towards one side of the storage tank. The application can realize the reduction of the static evaporation amount of liquid hydrogen through directional radiation refrigeration, thereby realizing low-loss liquid hydrogen storage, and the radiation refrigeration performance is excellent, and the reflecting device effect is remarkable.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of liquid hydrogen storage, and particularly relates to a low-loss liquid hydrogen storage device using directional radiation refrigeration technology. BACKGROUND

[0002] The liquid hydrogen storage tank generally adopts a spherical tank and a cylindrical tank in terms of structural form. Due to the characteristics of low boiling point, small latent heat of vaporization and easy evaporation of liquid hydrogen, the tank must adopt strict means to reduce heat leakage. The prior art mainly adopts passive heat insulation technology to reduce heat conduction, and superimposes active refrigeration technology to reduce heat leakage or generate additional cold.

[0003] The passive heat insulation technology includes high-vacuum heat insulation, vacuum powder heat insulation and vacuum multilayer heat insulation. The high-vacuum heat insulation has a high-vacuum heat insulation interlayer space, so as to reduce gas convection heat exchange and gas heat conduction. The effective heat conduction coefficient is in the order of 10 -2 W / (m·K). -3 The vacuum powder heat insulation fills a material with small heat conductivity in the vacuum interlayer, so as to reduce convective heat transfer. The effective heat conduction coefficient is in the order of 10 -6 W / (m·K). -4 The vacuum multilayer heat insulation adopts a multilayer reflective screen, so as to reduce radiation heat transfer on the basis of high-vacuum heat insulation. The effective heat conduction coefficient is in the order of 10

[0004] The active refrigeration technology usually uses a low-temperature storage tank and a refrigerator to realize active heat insulation. The refrigerator provides cold to balance the heat leakage of the tank. However, due to the complex structure of the refrigerator, the volume and weight of the whole device are increased. Moreover, the refrigerator has low efficiency, large energy consumption, high cost and poor economy.

[0005] Therefore, the person skilled in the art is committed to providing a low-loss liquid hydrogen storage device using directional radiation refrigeration technology. The radiation refrigeration technology and the passive heat insulation technology are combined to reduce the heat leakage of the liquid hydrogen storage tank, and the existing active refrigeration technology is replaced. SUMMARY

[0006] In view of the defects in the prior art, the technical problem to be solved by the present application is how to provide a liquid hydrogen storage device capable of reducing the heat leakage of a liquid hydrogen storage tank.

[0007] To achieve the above-mentioned purpose, the present application provides a low-loss liquid hydrogen storage device using directional radiation refrigeration technology, comprising:

[0008] a storage tank for storing liquid hydrogen;

[0009] a cladding member wrapped outside the storage tank;

[0010] An adiabatic member wrapped outside the cladding member can reduce heat conduction;

[0011] A radiative cooling film wrapped outside the adiabatic member can reflect radiative rays;

[0012] A reflecting member provided on one side of the storage tank can reflect radiative rays towards one side of the storage tank.

[0013] Further, the storage tank is spherical.

[0014] Further, the cladding member is made of glass beads.

[0015] Preferably, the thickness of the cladding member along the radial direction of the storage tank is 3 cm.

[0016] Further, the adiabatic member is a variable-density multilayer adiabatic layer, with a low-density layer close to the storage tank and a high-density layer away from the storage tank.

[0017] Preferably, the adiabatic member is composed of one or more of aluminum foil, aluminum-coated sheet and spacing material.

[0018] Further, the adiabatic member is internally vacuumed.

[0019] Preferably, the average layer density of the adiabatic member is 30 layers / cm, including 45 layers, with the number of layers in the low, medium and high temperature sections being 7, 15 and 23 respectively.

[0020] Further, the radiative cooling film is a visible transparent polymer film, and the polymer is wrapped with silica microspheres.

[0021] Further, the reflecting member is parabolic, and the storage tank is located on the focal side of the reflecting member.

[0022] The present application has at least the following beneficial technical effects:

[0023] The low-loss liquid hydrogen storage device provided by the present application utilizes directional radiative cooling technology, provides heat protection from conduction, convection and radiation, and reduces additional energy consumption; the directional radiative cooling can reduce the static evaporation of liquid hydrogen, thereby achieving low-loss liquid hydrogen storage, and the radiative cooling performance is excellent, the reflecting device has remarkable effect; the radiative cooling and passive adiabatic are combined to achieve weight reduction of the device.

[0024] The concept, specific structure and technical effects of the present application will be further described below with reference to the accompanying drawings, so as to fully understand the purpose, features and effects of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1This is a schematic diagram of the overall structure of a low-loss liquid hydrogen storage device utilizing directional radiation cooling technology according to an embodiment of the present invention.

[0026] Figure 2 This is a cross-sectional view of a low-loss liquid hydrogen storage device utilizing directional radiation cooling technology according to an embodiment of the present invention.

[0027] Figure 3 This is a radiation schematic diagram of a low-loss liquid hydrogen storage device utilizing directional radiation cooling technology according to an embodiment of the present invention.

[0028] In the figure, 1-hydrogen storage device, 11-storage tank, 12-cladding component, 13-insulation component, 14-radiative cooling film, 2-reflective component. Detailed Implementation

[0029] The preferred embodiments of the present invention are described below to make the technical content clearer and easier to understand. The present invention can be embodied in many different forms, and the scope of protection of the present invention is not limited to the embodiments mentioned herein.

[0030] In the accompanying drawings, components with the same structure are indicated by the same numerical designation, and components with similar structures or functions are indicated by similar numerical designations. The dimensions and thicknesses of each component shown in the drawings are arbitrary, and the present invention does not limit the dimensions and thicknesses of each component. To make the illustrations clearer, the thickness of some components has been appropriately exaggerated in the drawings.

[0031] This invention provides a low-loss liquid hydrogen storage device utilizing directional radiation cooling technology. A radiation cooling film is applied to the outermost layer of the passive insulation device, thereby improving the passive insulation power. By combining radiation cooling technology with passive insulation technology, the device achieves weight reduction while replacing the active cooling device in the prior art.

[0032] like Figure 1 As shown, the low-loss liquid hydrogen storage device utilizing directional radiation cooling technology in this embodiment includes a hydrogen storage device 1 and a reflector 2. The hydrogen storage device 1 is located on one side of the reflector 2. Liquid hydrogen is stored in the hydrogen storage device 1, which provides passive insulation for the liquid hydrogen. The reflector 2 provides radiation cooling for the hydrogen storage device 1.

[0033] like Figure 2 As shown, the innermost part of the hydrogen storage device 1 is the storage tank 11, which stores liquid hydrogen. The storage tank 11 is wrapped with a covering 12, an insulation 13 and a radiation cooling film 14 in a radial direction from the inside to the outside.

[0034] In this embodiment, the storage tank 11 is spherical. A sphere has the smallest specific surface area and the lowest heat loss rate; a spherical structure has high mechanical strength and uniform stress distribution. Therefore, the storage tank 11 in this embodiment is spherical.

[0035] The coating 12 is uniformly attached to the outer wall of the tank 11 and is made of glass beads. The tiny air gaps in the glass beads can effectively prevent heat transfer and reduce heat conduction, and the surface has high reflectivity to reflect heat radiation. The glass beads are light materials that can reduce the weight of the device. In addition, the glass beads have stable bulk density and are not prone to deformation and collapse.

[0036] The heat insulating member 13 is a variable-density vacuum multilayer heat insulating layer, which uses low-density layers near the inner side of the tank 11 and high-density layers on the outer side. The multilayer heat insulating structure of the heat insulating member 13 is composed of aluminum foil or aluminum-coated sheet and spacing material with low thermal conductivity, which is arranged between the aluminum foil or aluminum-coated sheet to form a multilayer structure. The inside of the heat insulating layer 13 is vacuumized, and the heat transfer is greatly reduced by the multilayer radiation screen in the heat insulating space parallel to the cold wall. The heat insulating layer 13 can reduce convective heat transfer and radiant heat transfer.

[0037] The radiation cooling film 14 is a micro-nanoparticle polymer film composed of a visible transparent polymer film, with randomly distributed silica microspheres wrapped inside. The radiation cooling film 14 can reflect radiation, has high emissivity in the entire atmospheric transmission window (8-13 μm), and can achieve continuous cooling in both day and night, indoors and outdoors, with few restrictions, low cost, relatively simple manufacturing process, and suitable for mass production and application.

[0038] In one specific embodiment, the hydrogen storage device 1 uses passive cooling technology, with the outermost layer attached to a radiation cooling film made of polymethylpentene as the base material and mixed with silica microspheres, using the atmospheric window as the cooling path to achieve the radiation of heat from the earth's surface to outer space. The reflectivity of the radiation cooling film to solar radiation can reach 96%, the infrared reflectivity in the atmospheric window band can reach 93%, and the passive cooling power of the radiation cooling film can reach 94 W / m 2 .

[0039] For conventional design, the radiation of the lower surface of the tank 11 is directed to the ground, and the radiation heat transfer is almost 0, so the effective radiation heat transfer area of the entire tank 11 is small. Therefore, as shown in Figure 1 , the shape of the reflecting member 2 is designed as a parabolic shape, and a reflecting material is coated on the side of the parabolic surface facing the focal point; the hydrogen storage device 1 is arranged on the side of the focal point of the reflecting member 2, i.e. in the open space of the parabolic surface, and the directional reflection of the radiation is realized by using the geometric properties of the parabolic surface.

[0040] In one specific embodiment, as shown in Figure 3As shown, the center of the sphere of the storage tank 11 is located at the focal point of the parabolic surface of the reflector 2. Due to symmetry, the emission point of the radiation energy emitted from the surface of the spherical storage tank 11 is equivalent to the center of the sphere. From the geometric properties of the parabola, the radiation, after reflection, is directed perpendicularly into outer space. In this embodiment, the lower surface of the storage tank 11 can achieve a temperature drop of 5°C, thereby increasing the effective heat exchange area of ​​the storage tank 11.

[0041] By combining radiative cooling technology and passive insulation technology, weight reduction in liquid hydrogen storage devices can be achieved. Under the same heat leakage conditions, radiative cooling films can lower the thermal boundary temperature, reduce the thickness of the inner glass microsphere layer, and decrease the number of layers in the variable-density multilayer material. In one specific embodiment, the thickness of the glass microsphere layer is 3 cm, and the average layer density of the variable-density vacuum multilayer insulation structure is 30 layers / cm, totaling 45 layers, with 7, 15, and 23 layers in the low, medium, and high-temperature sections, respectively.

[0042] like Figure 1 As shown, in this embodiment of the liquid hydrogen storage device, the outer side of the reflector 2 is provided with several diagonal braces, thereby supporting the reflector 2 on the ground or other locations, and making the opening direction of the reflector 2 face away from the ground; the inner side of the reflector 2 is provided with a support member, on which the hydrogen storage device 1 rests, thereby supporting the hydrogen storage device 1. In this embodiment, the support member is a frustum-shaped frame structure.

[0043] It should be noted that the storage device of the present invention can be used to store liquid oxygen, liquid nitrogen, liquid ammonia, liquid air, etc., in addition to storing liquid hydrogen. Moreover, these devices are structurally identical. Therefore, the scope of protection of the present invention is not limited to the medium it stores.

[0044] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, those skilled in the art can obtain the following results based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology.

Claims

1. A low-loss liquid hydrogen storage device utilizing directed radiation refrigeration technology, characterized by, The application relates to a liquid hydrogen storage tank, which comprises the following components: a storage tank for storing liquid hydrogen; a cover wrapped outside the storage tank; a thermal insulation layer wrapped outside the cover, capable of reducing heat transfer; a radiation cooling film wrapped outside the thermal insulation layer, capable of reflecting radiation; a reflector arranged on one side of the storage tank, capable of reflecting radiation towards the side of the storage tank; the reflector is parabolic, and the storage tank is located at the focal point side of the reflector; the radiation emitted by the surface of the storage tank is reflected by the reflector and vertically radiates to the outer space of the earth.

2. The low-loss liquid hydrogen storage device using the directed radiation refrigeration technique according to claim 1, wherein, The storage tank is spherical.

3. The low-loss liquid hydrogen storage device utilizing directed radiation refrigeration technology of claim 2, wherein, The cover is made of glass beads.

4. The low-loss liquid hydrogen storage device utilizing directed radiation refrigeration technology of claim 3, wherein, The thickness of the cover along the radial direction of the storage tank is 3 cm.

5. The low-loss liquid hydrogen storage device using the directed radiation refrigeration technique according to claim 3, wherein, The thermal insulation layer is a variable-density multilayer thermal insulation layer, the side close to the storage tank is a low-density layer, and the side far from the storage tank is a high-density layer.

6. The low-loss liquid hydrogen storage device utilizing directed radiation refrigeration technology of claim 5, wherein, The thermal insulation layer is composed of one or more of aluminum foil and aluminum-plated sheet and spacing material.

7. The low-loss liquid hydrogen storage device utilizing directed radiation refrigeration technology of claim 5, wherein, The inside of the thermal insulation layer is vacuumized.

8. The low-loss liquid hydrogen storage device utilizing directed radiation refrigeration technology of claim 5, wherein, The average layer density of the thermal insulation layer is 30 layers / cm, and the thermal insulation layer contains 45 layers, and the number of low-temperature, medium-temperature and high-temperature layers is 7, 15 and 23 respectively.

9. The low-loss liquid hydrogen storage device using the directed radiation refrigeration technique according to claim 2, wherein, The radiation cooling film is a visible transparent polymer film, and the polymer is wrapped with silica microspheres.

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