Low-temperature gas cylinder and preparation method thereof

Abstract

The invention relates to the technical field of heat preservation structures, and discloses a low-temperature gas cylinder and a preparation method thereof.The low-temperature gas cylinder comprises an inner cylinder suitable for storing low-temperature liquid; the outer cylinder is wrapped outside the inner cylinder, and a vacuum cavity is formed between the outer cylinder and the inner cylinder; the first heat preservation layer is arranged between the inner cylinder and the outer cylinder, and the first heat preservation layer wraps the outer portion of the inner cylinder; the coil pipe surrounds the outer side of the first heat preservation layer, one end of the coil pipe communicates with an inner cavity of the inner barrel, the low-temperature liquid is suitable for evaporating and absorbing heat in the coil pipe, and the other end of the coil pipe penetrates out of the outer barrel. According to the low-temperature gas cylinder, the coil pipe is arranged outside the inner cylinder, low-temperature liquid evaporates and absorbs heat in the coil pipe, heat transfer of the outer cylinder to the inner cylinder is reduced, and therefore evaporation loss of the low-temperature liquid in the inner cylinder is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of thermal insulation structures, and in particular to a cryogenic gas cylinder and a preparation method thereof. Background Art

[0002] Hydrogen energy is a clean energy source with abundant resource reserves and zero pollution in energy conversion (the reaction product is only water vapor). Compared with other forms of hydrogen storage, liquid hydrogen is currently the only energy carrier that meets the International Energy Agency (IEA)'s density standards for on-board hydrogen storage systems. This ultra-low temperature fuel has not only been maturely applied in cutting-edge fields such as aerospace, national defense and military, but its application scenarios are also gradually extending to the civilian market, such as hydrogen energy vehicles. Due to the extremely low storage temperature of liquid hydrogen (about -253°C), in order to reduce the evaporation loss of liquid hydrogen, the storage and transportation technology of liquid hydrogen is crucial. At present, on-board liquid hydrogen cylinders, as containers for storing liquid hydrogen, are usually double-layer structures. Vacuum is drawn between the inner and outer layers, and multiple layers of insulation material are wrapped around the inner cylinder to insulate the inner cylinder. However, this form of insulation has a simple structure, poor insulation performance, and large evaporation losses of liquid hydrogen, so the insulation performance needs to be further strengthened. Summary of the invention

[0003] In view of this, the present invention provides a cryogenic gas cylinder and a preparation method thereof, so as to solve the problem that the current vehicle-mounted liquid hydrogen gas cylinder has poor thermal insulation performance and a large evaporation loss of liquid hydrogen.

[0004] In a first aspect, the present invention provides a cryogenic gas cylinder, comprising:

[0005] An inner cylinder suitable for storing cryogenic liquid;

[0006] The outer cylinder is wrapped around the outside of the inner cylinder to form a vacuum chamber between the outer cylinder and the inner cylinder;

[0007] A first thermal insulation layer is disposed between the inner tube and the outer tube, and the first thermal insulation layer is wrapped around the outside of the inner tube;

[0008] The coil surrounds the outside of the first insulation layer, one end of the coil is connected to the inner cavity of the inner tube, the low-temperature liquid is suitable for evaporating and absorbing heat in the coil, and the other end of the coil passes through the outside of the outer tube.

[0009] Beneficial effects: By arranging a coil outside the inner tube, the low-temperature liquid is used to evaporate and absorb heat inside the coil, and the temperature of the inner tube is reduced through heat transfer. At the same time, the heat transfer from the outer tube to the inner tube is reduced, thereby reducing the evaporation loss of the low-temperature liquid inside the inner tube; and a first insulation layer is arranged between the coil and the inner tube to prevent the coil from rigidly colliding with the inner tube while playing a role in heat insulation, thereby protecting the inner tube and the coil.

[0010] In an optional embodiment, the outside of the coil is further wrapped with a second thermal insulation layer, and the second thermal insulation layer is arranged between the outer tube and the coil.

[0011] Beneficial effect: By setting a second insulation layer outside the coil, the coil and the outer tube are insulated, thereby further enhancing the insulation effect on the inner tube. The coil is sandwiched between the first insulation layer and the second insulation layer to further prevent the movement of the coil, thereby improving safety and durability.

[0012] In an optional embodiment, the thickness of the first thermal insulation layer is less than the thickness of the second thermal insulation layer.

[0013] In an optional embodiment, the pitch of the coil is 200mm-300mm.

[0014] In an optional embodiment, the outer diameter of the coil is 12 mm-14 mm, and the inner diameter of the coil is 9 mm-10 mm.

[0015] In an optional embodiment, the vacuum degree of the vacuum chamber is ≤1×10 -3 Pa.

[0016] Beneficial effect: reduce the vacuum degree to 1×10 -3 Pa, by setting the coil, the thermal insulation performance of the cryogenic gas cylinder of this solution is improved by more than 30% compared with the related art which only sets the thermal insulation layer.

[0017] In an optional embodiment, as shown in the figure, a heat-conducting section is provided on the outer cylinder, and the other end of the coil extends to the outside of the outer cylinder through the heat-conducting section.

[0018] In an optional embodiment, a first supporting structure and a second supporting structure are respectively provided at both ends of the inner cylinder, and the inner cylinder is connected to the outer cylinder via the first supporting structure and the second supporting structure.

[0019] Beneficial effect: The inner cylinder is connected to the outer cylinder via the first supporting structure and the second supporting structure to reduce the contact area between the inner cylinder and the outer cylinder, thereby reducing contact heat transfer, which is beneficial to thermal insulation of the inner cylinder.

[0020] In an optional embodiment, a temperature sensor is provided inside the inner tube and / or inside the coil; an opening regulating valve is provided on the coil, and the opening regulating valve is electrically connected to the temperature sensor so as to increase the opening when an increase in the rate of temperature increase is detected by the temperature sensor, or to decrease the opening when a decrease in the rate of temperature increase is detected by the temperature sensor.

[0021] Beneficial effect: By arranging the temperature sensor and the opening regulating valve, the fluctuation range of the heating rate of the inner tube can be reduced, which is beneficial to improving the stability of the thermal insulation effect of the inner tube.

[0022] In a second aspect, the present invention also provides a preparation method, comprising: wrapping a first insulation layer on the outside of an inner tube; winding a coil on the first insulation layer, and connecting one end of the coil to the inner tube; wrapping a second insulation layer on the side of the coil away from the first insulation layer; installing the inner tube inside the outer tube through a first supporting structure and a second supporting structure; extending the other end of the coil out of the outer tube through a heat-conducting section; evacuating the space between the inner tube and the outer tube; arranging a temperature sensor inside the inner tube and / or the coil; and arranging an opening regulating valve inside the coil, wherein the opening regulating valve is electrically connected to the temperature sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 This is a schematic structural diagram of a cryogenic gas cylinder according to an embodiment of the present invention;

[0025] Figure 2 for Figure 1 A partial enlarged schematic diagram of B in the middle;

[0026] Figure 3 for Figure 1 Schematic diagram of the AA section;

[0027] Figure 4 for Figure 1 A side view of the cryogenic cylinder is shown;

[0028] Figure 5 for Figure 1 A cross-sectional view of the second support structure is shown.

[0029] Description of reference numerals:

[0030] 1. Inner tube; 2. Outer tube; 3. First insulation layer; 4. Vacuum chamber; 5. Coil; 6. Exhaust joint; 7. Second insulation layer; 8. Heat transfer section; 81. First cavity; 82. Second cavity; 9. First supporting structure; 91. Outer tube; 92. First inner tube; 10. Second supporting structure; 101. Second inner tube; 102. Connecting part; 103; Third inner tube; 104. Cylindrical space; 105. Fixing part; 106. Limiting part. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0032] Combine the following Figures 1 to 5 , describing an embodiment of the present invention.

[0033] According to an embodiment of the present invention, on the one hand, a cryogenic gas cylinder is provided, comprising:

[0034] An inner cylinder 1, suitable for storing cryogenic liquid;

[0035] The outer tube 2 is wrapped around the outside of the inner tube 1 to form a vacuum chamber 4 between the outer tube 2 and the inner tube 1;

[0036] The first thermal insulation layer 3 is arranged between the inner tube 1 and the outer tube 2, and the first thermal insulation layer 3 is wrapped around the outer part of the inner tube 1;

[0037] The coil 5 surrounds the outside of the first insulation layer 3 , one end of the coil 5 is connected to the inner cavity of the inner tube 1 , the low-temperature liquid is suitable for evaporating and absorbing heat in the coil 5 , and the other end of the coil 5 passes through the outside of the outer tube 2 .

[0038] The cryogenic gas cylinder provided in this embodiment is provided with a coil 5 outside the inner tube 1, so as to utilize the low-temperature liquid to evaporate and absorb heat inside the coil 5, and reduce the temperature of the inner tube through heat transfer. At the same time, the heat transfer from the outer tube 2 to the inner tube 1 is reduced, thereby reducing the evaporation loss of the low-temperature liquid inside the inner tube 1; and a first thermal insulation layer 3 is provided between the coil 5 and the inner tube 1, so as to prevent the coil 5 from rigidly colliding with the inner tube 1 while playing a role in thermal insulation, thereby playing a role in protecting the inner tube 1 and the coil 5.

[0039] Specifically, the cryogenic gas cylinder is constructed as a double-layer structure, including an inner cylinder 1 and an outer cylinder 2. The outer cylinder 2 is made of high-strength stainless steel material so as to have good mechanical properties and impact resistance. The wall thickness of the inner cylinder 1 is 1.5 mm, and the wall thickness of the outer cylinder 2 is 2 mm, wherein there is a spacing between the outer wall of the inner cylinder 1 and the inner wall of the outer cylinder 2. The space between the inner cylinder 1 and the outer cylinder 2 is evacuated to form a vacuum chamber 4, thereby improving the thermal insulation effect of the inner cylinder 1. The outer cylinder 2 is provided with an exhaust joint 6, which is used to connect to the vacuum equipment to evacuate the space between the inner cylinder 1 and the outer cylinder 2.

[0040] A liquid-using device is provided outside the cryogenic gas cylinder, and the inner tube 1 is connected to the liquid-using device through a delivery pipeline, and the delivery pipeline is used to provide vaporized cryogenic liquid to the liquid-using device. The other end of the coil 5 extends out of the outer tube 2 and is connected to the liquid-using device. The cryogenic liquid is evaporated inside the coil 5 to absorb the heat around the coil 5, and the temperature of the inner tube 1 is reduced by heat transfer to avoid wasting the cryogenic liquid. The inner tube 1 and the coil 5 are separated by the first thermal insulation layer 3, which can avoid direct contact between the coil 5 and the inner tube 1 and avoid structural damage to the coil 5 and the inner tube 1 caused by rigid collision in a vibration environment. Taking a liquid hydrogen vehicle as an example, the cryogenic gas cylinder is installed on the vehicle, and the liquid hydrogen is stored inside the inner tube 1 as a cryogenic liquid. After absorbing heat and vaporizing in the coil 5, it is transported to the fuel cell of the liquid hydrogen vehicle. During the movement of the vehicle, the cryogenic gas cylinder is in a vibration environment, and the first thermal insulation layer 3 is used to avoid rigid collision between the coil 5 and the inner tube 1.

[0041] In one embodiment, in combination Figure 1 and Figure 2 As shown, the outside of the coil 5 is also wrapped with a second thermal insulation layer 7 , and the second thermal insulation layer 7 is arranged between the outer tube 2 and the coil 5 .

[0042] The cryogenic gas cylinder provided in this embodiment has a second thermal insulation layer 7 disposed outside the coil 5 to provide thermal insulation between the coil 5 and the outer cylinder 2 , thereby further enhancing the thermal insulation of the inner cylinder 1 .

[0043] In one embodiment, the thickness of the first thermal insulation layer 3 is smaller than the thickness of the second thermal insulation layer 7 .

[0044] Specifically, the first thermal insulation layer 3 includes at least two layers of thermal radiation reflective film, and the second thermal insulation layer 7 includes at least one hundred layers of thermal radiation reflective film. The thermal radiation reflective film includes a multilayer structure formed by alternating deposition of aluminum layers and silicon oxide layers. The thickness of the aluminum layer is 20nm-50nm, and the thickness of the silicon oxide layer is 100nm-150nm.

[0045] In one embodiment, the pitch of the coil 5 is 200 mm-300 mm.

[0046] Exemplarily, in some embodiments, the pitch of the coil 5 can be 200 mm or 210 mm or 220 mm or 230 mm or 240 mm or 250 mm or 260 mm or 270 mm or 280 mm or 290 mm or 300 mm, etc., or can be an interval range formed by any two of the above values.

[0047] In one embodiment, the outer diameter of the coil 5 is 12 mm-14 mm, and the inner diameter of the coil 5 is 9 mm-10 mm.

[0048] For example, in some embodiments, the outer diameter of the coil 5 can be 12 mm, 13 mm, 14 mm, etc., or a range formed by any two of the above values; the inner diameter of the coil 5 can be 9 mm, 9.5 mm, 10 mm, etc., or a range formed by any two of the above values.

[0049] In one embodiment, the vacuum degree of the vacuum chamber 4 is ≤1×10 -3 Pa.

[0050] Exemplarily, in some embodiments, the pitch of the coil 5 can be 200 mm or 210 mm or 220 mm or 230 mm or 240 mm or 250 mm or 260 mm or 270 mm or 280 mm or 290 mm or 300 mm, etc., or can be an interval range formed by any two of the above values.

[0051] Specifically, compared with the structure in the related art in which only one insulation layer is arranged on the outside of the inner cylinder 1, the cryogenic gas cylinder provided in the present solution can improve the thermal insulation performance by more than 30% by evacuating the space between the inner cylinder 1 and the outer cylinder 2 and sequentially arranging the first insulation layer 3, the coil 5 and the second insulation layer 7 on the outside of the inner cylinder 1.

[0052] In one embodiment, in combination Figure 1 and Figure 2 As shown, a heat-conducting section 8 is provided on the outer tube 2 , and the other end of the coil 5 extends to the outside of the outer tube 2 through the heat-conducting section 8 .

[0053] Specifically, the heat conducting section 8 is provided on the shell of the outer tube 2, and the coil 5 is provided inside the heat conducting section 8. A second cavity 82 wrapping the coil 5 and a first cavity 81 surrounding the second cavity 82 are formed inside the heat conducting section 8. The first cavity 81 and the second cavity 82 are connected to the vacuum chamber 4, so that two layers of vacuum areas are formed between the coil 5 and the heat conducting section 8. Since the temperature difference between the inside and outside of the outer tube 2 is large, the heat conducting section 8 is provided to avoid excessive temperature difference between the coil 5 and the inside and outside of the outer tube 2.

[0054] In one embodiment, in combination Figure 1 and Figure 5 As shown, a first supporting structure 9 and a second supporting structure 10 are respectively provided at both ends of the inner cylinder 1 , and the inner cylinder 1 is connected to the outer cylinder 2 via the first supporting structure 9 and the second supporting structure 10 .

[0055] In the cryogenic gas cylinder provided in this embodiment, the inner cylinder 1 is connected to the outer cylinder 2 via the first support structure 9 and the second support structure 10 to reduce the contact area between the inner cylinder 1 and the outer cylinder 2, thereby reducing contact heat transfer, which is beneficial to thermal insulation of the inner cylinder 1.

[0056] Specifically, the first supporting structure 9 includes an outer tube 91 and a first inner tube 92 . The outer tube 91 is fixedly connected to the inner wall of the outer tube 2 . The first inner tube 92 is arranged corresponding to the outer tube 91 and fixedly connected to the inner tube 1 . The first inner tube 92 is slidably arranged inside the outer tube 91 .

[0057] The second support structure 10 includes a second inner tube 101 fixedly connected to the inner wall of the outer tube 2, the inner tube 1 is recessed corresponding to the second inner tube 101 to form a cylindrical space 104, a third inner tube 103 is fixedly connected inside the cylindrical space 104, and the third inner tube 103 is fixedly connected to the second inner tube 101 through a connecting portion 102. Since the cylindrical space 104 is recessed into the inner tube 1, relative to the connecting portion 102 being directly arranged between the inner tube 1 and the outer tube 2, the connecting portion 102 is suitable for having a longer strain generating area, so that in a vibration environment, it has a better vibration absorbing effect, which is conducive to reducing the vibration amplitude of the inner tube 1. Furthermore, a fixing portion 105 is fixedly connected to the outside of the connecting portion 102, and a plurality of limiting portions 106 are fixedly connected to the inner wall of the cylindrical space 104. The plurality of limiting portions 106 are respectively located at both ends of the fixing portion 105 along the length direction of the connecting portion 102. The limiting portions 106 are suitable for abutting against the fixing portion 105, thereby improving the stability of the connection between the second inner tube 101 and the third inner tube 103 through the connecting portion 102.

[0058] In one embodiment, a temperature sensor is provided inside the inner tube 1 and / or inside the coil 5; an opening regulating valve is provided on the coil 5, and the opening regulating valve is electrically connected to the temperature sensor so as to increase the opening when an increase in the temperature rise rate is detected by the temperature sensor, or to decrease the opening when a decrease in the temperature rise rate is detected by the temperature sensor.

[0059] The cryogenic gas cylinder provided in this embodiment is provided with a temperature sensor and an opening regulating valve so as to reduce the fluctuation amplitude of the heating rate of the inner cylinder 1 , which is beneficial to improving the stability of the heat preservation effect of the inner cylinder 1 .

[0060] Specifically, if the flow rate of cryogenic liquid entering the coil 5 remains unchanged, when the ambient temperature outside the cryogenic gas cylinder changes significantly in a short period of time, the temperature inside the vacuum chamber 4 may change significantly, thereby affecting the temperature change stability inside the inner tube 1. The flow rate of cryogenic liquid entering the coil 5 is adjusted by the opening regulating valve to adjust the heat absorption effect of the coil 5, thereby improving the temperature change amplitude of the inner tube 1.

[0061] According to an embodiment of the present invention, on the other hand, a preparation method is also provided, comprising: wrapping a first insulation layer 3 on the outside of an inner tube 1; winding a coil 5 on the first insulation layer 3, and connecting one end of the coil 5 to the inner tube 1; wrapping a second insulation layer 7 on the side of the coil 5 away from the first insulation layer 3; installing the inner tube 1 inside the outer tube 2 through a first support structure 9 and a second support structure 10; a heat conduction section 8 is provided on the outer tube 2, and the other end of the coil 5 extends out of the outer tube 2 through the heat conduction section 8; evacuating the space between the inner tube 1 and the outer tube 2; providing a temperature sensor inside the inner tube 1 and / or the coil 5; and providing an opening regulating valve inside the coil 5, and the opening regulating valve is electrically connected to the temperature sensor.

[0062] Specifically, the first thermal insulation layer 3 is formed by wrapping at least two layers of heat radiation reflection film, and the second thermal insulation layer 7 is formed by wrapping at least one hundred layers of heat radiation reflection film. The space between the inner tube 1 and the outer tube 2 is evacuated using a vacuum device, and the vacuum degree is less than or equal to 1×10 -3 Pa. The first insulation layer 3, the coil 5 and the second insulation layer 7 are sequentially arranged outside the inner tube 1 to improve the insulation effect of the cryogenic gas cylinder, and the opening regulating valve and the temperature sensor are arranged to improve the stability of the insulation effect.

[0063] Obviously, the above embodiments are only examples for clear explanation, and are not intended to limit the implementation methods. Although the embodiments of the present invention are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the present invention.

Claims

1. A cryogenic gas cylinder, characterized in that: include: An inner cylinder (1) suitable for storing cryogenic liquid; An outer cylinder (2) is arranged to wrap around the outside of the inner cylinder (1) and to form a vacuum chamber (4) between the outer cylinder (2) and the inner cylinder (1); A first thermal insulation layer (3) is arranged between the inner tube (1) and the outer tube (2), and the first thermal insulation layer (3) is wrapped around the outside of the inner tube (1); A coil (5) surrounds the outside of the first thermal insulation layer (3), one end of the coil (5) is connected to the inner cavity of the inner tube (1), the low-temperature liquid is suitable for evaporating and absorbing heat in the coil (5), and the other end of the coil (5) passes through the outside of the outer tube (2).

2. The cryogenic gas cylinder according to claim 1, characterized in that: The coil (5) is also wrapped with a second thermal insulation layer (7) on the outside, and the second thermal insulation layer (7) is arranged between the outer cylinder (2) and the coil (5).

3. The cryogenic gas cylinder according to claim 2, characterized in that: The thickness of the first thermal insulation layer (3) is smaller than the thickness of the second thermal insulation layer (7).

4. The cryogenic gas cylinder according to claim 1, characterized in that: The pitch of the coil (5) is 200mm-300mm.

5. The cryogenic gas cylinder according to claim 4, characterized in that: The outer diameter of the coil (5) is 12 mm-14 mm, and the inner diameter of the coil (5) is 9 mm-10 mm.

6. The cryogenic gas cylinder according to claim 1, characterized in that: The vacuum degree of the vacuum chamber (4) is ≤1×10 -3 Pa.

7. The cryogenic gas cylinder according to any one of claims 1 to 6, characterized in that: The outer cylinder (2) is provided with a heat-conducting section (8), and the other end of the coil (5) extends to the outside of the outer cylinder (2) through the heat-conducting section (8).

8. The cryogenic gas cylinder according to any one of claims 1 to 6, characterized in that: A first supporting structure (9) and a second supporting structure (10) are respectively provided at both ends of the inner cylinder (1), and the inner cylinder (1) is connected to the outer cylinder (2) via the first supporting structure (9) and the second supporting structure (10).

9. The cryogenic gas cylinder according to any one of claims 1 to 6, characterized in that: A temperature sensor is arranged inside the inner tube (1) and / or inside the coil (5); an opening regulating valve is arranged on the coil (5), and the opening regulating valve is electrically connected to the temperature sensor so as to increase the opening when the temperature sensor detects that the temperature rise rate increases, or decrease the opening when the temperature sensor detects that the temperature rise rate decreases.

10. A method for preparing a cryogenic gas cylinder, for preparing a cryogenic gas cylinder as claimed in any one of claims 1 to 9, characterized in that: include: A first thermal insulation layer (3) is wrapped around the outside of the inner tube (1); a coil (5) is wound around the first thermal insulation layer (3), and one end of the coil (5) is connected to the inner tube (1); a second thermal insulation layer (7) is wrapped around the side of the coil (5) facing away from the first thermal insulation layer (3); the inner tube (1) is installed inside the outer tube (2) through a first supporting structure (9) and a second supporting structure (10); a heat conduction section (8) is provided on the outer tube 2, and the other end of the coil (5) extends out of the outer tube (2) through the heat conduction section (8); the space between the inner tube (1) and the outer tube (2) is evacuated; a temperature sensor is provided inside the inner tube (1) and / or the coil (5); an opening regulating valve is provided on the coil (5), and the opening regulating valve is electrically connected to the temperature sensor.

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