A LNG gas cylinder

Abstract

The present invention provides an LNG gas cylinder, the gas cylinder comprises an inner liner and an outer liner, the two ends of the outer liner are independently reduced in diameter by 4 to 5 mm, a first reinforcement ring is provided at the reduced diameter position of the outer wall of the outer liner, the first reinforcement ring is fixedly connected to the outer wall of the outer liner, and a second reinforcement ring is independently provided at the two ends of the outer wall of the inner liner, the second reinforcement ring is fixedly connected to the outer wall of the inner liner. While reducing the weight of the LNG gas cylinder, by reducing the diameter of the two ends of the outer liner, the welding quality of the reinforcement ring is improved, the problem of stress concentration at the position of the outer liner reinforcement ring is avoided, and the strength of the LNG gas cylinder is ensured.

Description

Technical Field

[0001] The invention belongs to the field of gas cylinder design and relates to an LNG gas cylinder. Background Art

[0002] LNG—Liquefied Natural Gas, is formed by liquefying natural gas at -162℃. Its main component is alkane (CH4). It is recognized as one of the clean energy sources in the world. Its pollution to the environment is far less than that of oil and coal. Density 430-470 (kg / m 3 ), which is three times that of CNG. It has a large storage capacity and a long driving range. Taking the current mainstream 1000L gas cylinder as an example, it can last for 1800-2500 kilometers. It has a price advantage over diesel and is currently favored by long-distance logistics vehicles.

[0003] From 2015 to 2019, sales of natural gas commercial vehicles increased from 22,285 units to 87,869 units, with an average annual compound growth rate of 40.91%. With the gradual introduction of industrial policies and the improvement of natural gas infrastructure construction, the supply capacity of natural gas has gradually increased, the supply and demand relationship of natural gas has tended to be stable, and the market prospects for natural gas vehicles are optimistic.

[0004] However, the existing LNG cylinders are heavy and do not meet the requirements of today's lightweight technology. How to reduce the weight of the LNG cylinders while ensuring the strength of the LNG cylinders while ensuring the volume of the LNG cylinders is a technical problem that needs to be solved urgently. Summary of the invention

[0005] In order to solve the technical problems existing in the prior art, the present invention provides an LNG gas cylinder. While reducing the weight, the LNG gas cylinder improves the welding quality of the reinforcement ring by reducing the diameter of the two ends of the outer liner, avoids the problem of stress concentration at the position of the outer liner reinforcement ring, and ensures the strength of the LNG gas cylinder.

[0006] In order to achieve the above technical effects, the present invention adopts the following technical solutions:

[0007] The present invention provides an LNG gas cylinder, which includes an inner liner and an outer liner. The two ends of the outer liner are independently reduced in diameter by 4 to 5 mm. A first reinforcement ring is provided at the reduced diameter position of the outer wall of the outer liner, and the first reinforcement ring is fixedly connected to the outer wall of the outer liner. Second reinforcement rings are independently provided at the two ends of the outer wall of the inner liner, and the second reinforcement ring is fixedly connected to the outer wall of the inner liner.

[0008] Among them, the two ends of the outer liner can independently shrink inward by 4mm, 4.1mm, 4.2mm, 4.3mm, 4.4mm, 4.5mm, 4.6mm, 4.7mm, 4.8mm, 4.9mm or 5mm, etc., but are not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0009] In the present invention, if the reinforcement ring is set on the inner wall of the outer liner, both sides of the ring need to be welded, and the welding process needs to be completed inside the outer liner, resulting in the welding quality cannot be guaranteed. If the reinforcement ring is set on the outer wall of the outer liner, the reinforcement ring contacts the ground first during the collision test, and the outer liner surface of the gas cylinder itself cannot contact the ground to withstand the collision stress, which can easily cause stress concentration problems at the ring. By adopting a reduction method, the outer surface of the reinforcement ring and the outer wall of the outer liner are in the same plane, avoiding the stress concentration problem of the reinforcement ring during the collision test, and the welding can be mechanized, which improves the welding quality and further improves the strength of the gas cylinder.

[0010] As a preferred technical solution of the present invention, the width of the reduced diameter portion of the outer liner is 35-50mm, such as 35mm, 36mm, 37mm, 38mm, 39mm, 40mm, 41mm, 42mm, 43mm, 44mm, 45mm, 46mm, 47mm, 48mm, 49mm or 50mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0011] In the present invention, the width of the reduced diameter portion of the outer bladder is equal to or slightly wider than the width of the reinforcement ring.

[0012] As a preferred technical solution of the present invention, the thickness of the first reinforcement ring is 4 to 5 mm, such as 4 mm, 4.1 mm, 4.2 mm, 4.3 mm, 4.4 mm, 4.5 mm, 4.6 mm, 4.7 mm, 4.8 mm, 4.9 mm or 5 mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0013] Preferably, the width of the first reinforcement ring is 35-45 mm, such as 35 mm, 36 mm, 37 mm, 38 mm, 39 mm, 40 mm, 41 mm, 42 mm, 43 mm, 44 mm or 45 mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0014] As a preferred technical solution of the present invention, the thickness of the second reinforcement ring is 4 to 5 mm, such as 4 mm, 4.1 mm, 4.2 mm, 4.3 mm, 4.4 mm, 4.5 mm, 4.6 mm, 4.7 mm, 4.8 mm, 4.9 mm or 5 mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0015] Preferably, the width of the second reinforcement ring is 35-45 mm, such as 35 mm, 36 mm, 37 mm, 38 mm, 39 mm, 40 mm, 41 mm, 42 mm, 43 mm, 44 mm or 45 mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0016] As a preferred technical solution of the present invention, the thickness of the outer liner is 2.5-3.5 mm, such as 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm, 3.0 mm, 3.1 mm, 3.2 mm, 3.3 mm, 3.4 mm or 3.5 mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0017] As a preferred technical solution of the present invention, the length of the outer bladder is 1650-1700mm, such as 1650mm, 1660mm, 1670mm, 1680mm, 1690mm or 1700mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0018] Preferably, the inner diameter of the outer liner is 900-910mm, such as 900mm, 901mm, 902mm, 903mm, 904mm, 905mm, 906mm, 907mm, 908mm, 909mm or 910mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0019] As a preferred technical solution of the present invention, the thickness of the inner liner is 3.5-4.5 mm, such as 3.5 mm, 3.6 mm, 3.7 mm, 3.8 mm, 3.9 mm, 4.0 mm, 4.1 mm, 4.2 mm, 4.3 mm, 4.4 mm or 4.5 mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0020] As a preferred technical solution of the present invention, the length of the inner liner is 1400-1450mm, such as 1400mm, 1410mm, 1420mm, 1430mm, 1440mm or 1450mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0021] Preferably, the inner diameter of the liner is 840-850 mm, such as 840 mm, 841 mm, 842 mm, 843 mm, 844 mm, 845 mm, 846 mm, 847 mm, 848 mm, 849 mm or 850 mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0022] As a preferred technical solution of the present invention, the material of the outer liner and the outer liner are independently stainless steel.

[0023] As a preferred technical solution of the present invention, the materials of the first reinforcement ring and the second reinforcement ring are independently stainless steel.

[0024] In the present invention, the stainless steel material of the outer liner, the inner liner, the first reinforcement ring and the second reinforcement ring is preferably 304 stainless steel.

[0025] In the present invention, the first reinforcement ring and the second reinforcement ring are independently connected to the inner liner or the outer liner by welding.

[0026] Compared with the prior art, the present invention has at least the following beneficial effects:

[0027] The present invention provides an LNG gas cylinder, which is about 30% lighter than the original LNG gas cylinder. However, the strength of the LNG gas cylinder is ensured by the provision of a reinforcement ring, and the welding quality of the reinforcement ring is improved by reducing the diameter of both ends of the outer liner, thereby avoiding the problem of stress concentration at the position of the outer liner reinforcement ring. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of the outer liner structure of an LNG gas cylinder provided in a specific embodiment of the present invention;

[0029] Figure 2 A cross-sectional view of the outer liner of an LNG gas cylinder provided in a specific embodiment of the present invention;

[0030] Figure 3 A schematic diagram of the inner liner structure of an LNG gas cylinder provided in a specific embodiment of the present invention;

[0031] Figure 4 A cross-sectional view of the inner liner of an LNG gas cylinder provided in a specific embodiment of the present invention.

[0032] The present invention is further described in detail below. However, the following examples are only simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims. DETAILED DESCRIPTION

[0033] To better illustrate the present invention and facilitate understanding of the technical solution of the present invention, typical but non-limiting embodiments of the present invention are as follows:

[0034] Example 1

[0035] This embodiment provides an LNG gas cylinder, such as Figure 1-4 As shown, the gas cylinder includes an inner liner and an outer liner, the outer liner has a thickness of 3mm, a length of 1670mm, and an inner diameter of 904mm, the inner liner has a thickness of 4mm, a length of 1430mm, and an inner diameter of 842mm; the two ends of the outer liner are independently reduced in diameter by 4mm, the width of the reduced diameter portion is 42mm, and a first reinforcement ring is provided at the reduced diameter position of the outer wall of the outer liner; a second reinforcement ring is provided at each of the two top ends of the outer wall of the inner liner; the first reinforcement ring has a thickness of 4mm and a width of 40mm; the second reinforcement ring has a thickness of 4mm and a width of 40mm.

[0036] Example 2

[0037] The present embodiment provides an LNG gas cylinder, which includes an inner liner and an outer liner. The outer liner has a thickness of 2.5 mm, a length of 1650 mm, and an inner diameter of 900 mm. The inner liner has a thickness of 3.5 mm, a length of 1400 mm, and an inner diameter of 840 mm. The two ends of the outer liner are independently reduced inward by 4.5 mm, and the width of the reduced diameter portion is 35 mm. A first reinforcement ring is provided at the reduced diameter position of the outer wall of the outer liner; a second reinforcement ring is provided at each of the two top ends of the outer wall of the inner liner; the first reinforcement ring has a thickness of 4.5 mm and a width of 35 mm; the second reinforcement ring has a thickness of 4.5 mm and a width of 35 mm.

[0038] Example 3

[0039] This embodiment provides an LNG gas cylinder, which includes an inner liner and an outer liner, wherein the outer liner has a thickness of 3.5 mm, a length of 1700 mm, and an inner diameter of 910 mm, and the inner liner has a thickness of 4.5 mm, a length of 1450 mm, and an inner diameter of 850 mm; the two ends of the outer liner are independently reduced inward by 5 mm, and the width of the reduced diameter portion is 48 mm, and a first reinforcement ring is provided at the reduced diameter position of the outer wall of the outer liner; a second reinforcement ring is provided at each of the two top ends of the outer wall of the inner liner; the first reinforcement ring has a thickness of 5 mm and a width of 45 mm; the second reinforcement ring has a thickness of 5 mm and a width of 45 mm. The cross section of the first reinforcement ring is an isosceles triangle, and the cross section of the second reinforcement ring is a rectangle.

[0040] Comparative Example 1

[0041] This comparative example provides an LNG gas cylinder, which is the same as Example 1 except that the reinforcement ring is not provided.

[0042] Comparative Example 2

[0043] This comparative example provides an LNG gas cylinder, except that the inner liner is not provided with a reinforcement ring, the other conditions are the same as those of Example 1.

[0044] Comparative Example 3

[0045] This comparative example provides an LNG gas cylinder, except that the outer liner is not provided with a reinforcement ring, the other conditions are the same as those of Example 1.

[0046] Comparative Example 4

[0047] This comparative example provides an LNG gas cylinder, except that the two ends of the outer liner are not reduced in diameter, and the other conditions are the same as those of Example 1.

[0048] Comparative Example 5

[0049] This comparative example provides an LNG gas cylinder, except that the outer liner does not shrink in diameter and a reinforcement ring is provided on the corresponding inner wall, the other conditions are the same as those of Example 1.

[0050] In Examples 1-3 and Comparative Examples 1-5, the inner liner, the outer liner, the first reinforcement ring and the second reinforcement ring are made of 304 stainless steel, and the cross-sections of the first reinforcement ring and the second reinforcement ring are rectangular.

[0051] A drop test was conducted on an LNG gas cylinder provided in Example 1-5 and Comparative Example 1-4. The drop height was 10 meters. The stress and displacement of the inner liner and the outer liner were tested. The specific test method was GB / T34510-2017. The results are shown in Table 1.

[0052] Table 1

[0053] External bladder stress Inner tank stress Outer bladder displacement Liner displacement Example 1 493MPa 432MPa 7.90％ 3.71％ Example 2 528MPa 514MPa 10.39％ 9.31％ Example 3 468MPa 467MPa 6.36％ 6.44％ Comparative Example 1 567MPa 667MPa 12.59％ 17.92％ Comparative Example 2 501MPa 475MPa 8.01％ 8.97％ Comparative Example 3 515MPa 502MPa 8.38％ 7.29％ Comparative Example 4 509MPa 451MPa 8.35％ 4.90％ Comparative Example 5 502MPa 466MPa 8.29％ 4.82％

[0054] It can be seen from the test results in Table 1 that the drop test results of the LNG cylinders provided in Examples 1-3 of the present application are excellent, indicating that the LNG cylinders have high strength. Comparative Examples 1-3 do not have a reinforcement ring, the inner liner does not have a reinforcement ring, and the outer liner does not have a reinforcement ring, and the drop test results of the LNG cylinders are worse, and the strength of the LNG cylinders is reduced; Comparative Example 4 does not perform a diameter reduction treatment, resulting in stress concentration at the reinforcement ring during the drop test, and the drop test results are worse; Comparative Example 5 has a reinforcement ring on the inner wall of the outer liner, and its drop test results are slightly lower than those of Example 1.

[0055] The applicant declares that the present invention illustrates the detailed structural features of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed structural features, that is, it does not mean that the present invention must rely on the above-mentioned detailed structural features to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the components selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0056] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0057] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0058] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. An LNG cylinder, characterized in that: The gas cylinder comprises an inner liner and an outer liner, the two ends of the outer liner are independently reduced in diameter by 4 to 5 mm, a first reinforcement ring is provided at the reduced diameter position of the outer wall of the outer liner, the first reinforcement ring is fixedly connected to the outer wall of the outer liner, the thickness of the first reinforcement ring is 4 to 5 mm, and the two ends of the outer wall of the inner liner are independently provided with second reinforcement rings, the second reinforcement ring is fixedly connected to the outer wall of the inner liner; The width of the reduced diameter portion of the outer liner is 35-50 mm; The width of the first reinforcement ring is 35-45 mm.

2. The LNG cylinder according to claim 1, characterized in that: The thickness of the second reinforcement ring is 4-5 mm.

3. The LNG cylinder according to claim 1, characterized in that: The width of the second reinforcement ring is 35-45 mm.

4. The LNG cylinder according to claim 1, characterized in that: The thickness of the outer liner is 2.5-3.5 mm.

5. The LNG cylinder according to claim 1, characterized in that: The length of the outer bladder is 1650-1700 mm.

6. The LNG cylinder according to claim 1, characterized in that: The inner diameter of the outer bladder is 900-910 mm.

7. The LNG cylinder according to claim 1, characterized in that: The thickness of the liner is 3.5-4.5 mm.

8. The LNG cylinder according to claim 1, characterized in that: The length of the inner liner is 1400-1450 mm.

9. The LNG cylinder according to claim 1, characterized in that: The inner diameter of the liner is 840-850 mm.

10. The LNG cylinder according to claim 1, characterized in that: The outer liner and the inner liner are made of stainless steel respectively and independently.

11. The LNG cylinder according to claim 1, characterized in that: The first reinforcement ring and the second reinforcement ring are independently made of stainless steel.

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