An LNG vacuum cryogenic liquid storage tank

Abstract

The present invention provides an LNG vacuum cryogenic liquid storage tank, which relates to the technical field of storage tanks. The LNG vacuum cryogenic liquid storage tank includes: a tank body, a heat insulation cavity, a heat dissipation cavity, an LNG storage cavity, two through pipes, a liquid nitrogen tank, a switch structure, an elastic member and a safety valve. When in use, LNG is placed into the LNG storage cavity in the tank body. When the heat outside the LNG storage tank enters the LNG storage tank, it will cause the volatilization of LNG, thereby increasing the air pressure in the storage tank. Once the air pressure exceeds the safety value of the safety valve, the safety valve opens, and the gas is discharged from the air outlet end of the safety valve and pushes the switch structure to open the channels of the two through pipes. Furthermore, the liquid nitrogen in the liquid nitrogen tank will enter the heat dissipation cavity through the through pipe communicated with it. Since the boiling point of liquid nitrogen is lower than that of LNG, the liquid nitrogen will absorb the heat of LNG and volatilize, and then be discharged along the other through pipe, thereby achieving the purpose of cooling LNG, inhibiting the volatilization of LNG and inhibiting the increase of the air pressure in the storage tank, and reducing the risk of tank explosion.

Description

Technical Field

[0001] The present invention relates to the technical field of storage tanks, and specifically relates to an LNG vacuum cryogenic liquid storage tank. Background Art

[0002] LNG, namely liquefied natural gas, is natural gas that is obtained by purifying the natural gas produced in a gas field and then undergoing a series of ultra-low temperature liquefactions to become a liquid under normal pressure. It is recognized as the cleanest fossil energy on earth. The LNG manufacturing process first purifies the natural gas produced in the gas field, and after a series of ultra-low temperature liquefactions, it is transported by LNG carriers. The combustion of liquefied natural gas causes very little air pollution and releases a large amount of heat, so it is a relatively advanced energy source. The main component of LNG is methane, which is colorless, odorless, non-toxic and non-corrosive.

[0003] LNG storage tanks are used to store LNG (liquefied natural gas). Currently, the domestic technology for large LNG fuel storage tanks in China has been basically mature. They are mainly dedicated to LNG storage and transportation, and generally adopt the low-temperature and normal-pressure mode.

[0004] In the prior art, when an LNG storage tank stores and transports LNG, due to the low temperature of the liquid natural gas, the heat outside the LNG storage tank will be transmitted into the LNG storage tank. Moreover, when the heat insulation effect of the storage tank is accidentally lost (such as when the heat insulation layer of the storage tank is damaged in a car accident), the heat outside the LNG storage tank will be transmitted into the LNG storage tank even more quickly. This is likely to cause a large amount of LNG to volatilize, thereby increasing the air pressure inside the storage tank and increasing the risk of explosion. Summary of the Invention

[0005] The purpose of the present invention is to provide an LNG vacuum cryogenic liquid storage tank, aiming to solve the problem in the prior art that the heat outside the LNG storage tank is easily transmitted into the LNG storage tank, causing the volatilization of LNG, thereby increasing the air pressure inside the storage tank and increasing the risk of explosion.

[0006] To achieve the above purpose, the present invention adopts the following technical solutions: The LNG vacuum cryogenic liquid storage tank includes:

[0007] A tank body, which is sequentially divided into a heat insulation cavity, a heat dissipation cavity and an LNG storage cavity from outside to inside;

[0008] Two through pipes, which are hermetically connected to the heat dissipation cavity and lead to the outside of the tank;

[0009] A liquid nitrogen tank, which is hermetically connected to one of the through pipes and is used to contain liquid nitrogen;

[0010] A switch structure, which is arranged on the tank body and the two through pipes and is used to open or close the channels of the two through pipes;

[0011] An elastic member is provided on the switch structure and the tank body and is used to drive the switch structure to close the channels of the two through pipes.

[0012] A safety valve, the intake end of the safety valve is hermetically connected to the LNG storage cavity, the outlet end of the safety valve extends outside the tank and corresponds to the switch structure, and the gas released by the safety valve can push the switch structure to open the channels of the two through pipes.

[0013] A further technical solution of the present invention is that the switch structure includes two slots respectively opened on the two through pipes. The inner walls of the two slots are both slidably connected with sliding plates. Both of the two sliding plates are provided with a blocking part and a communicating part. A transmission member corresponding to the intake end of the safety valve is provided between the two sliding plates. The gas released by the safety valve can push the transmission member to move. The movement of the transmission member can drive the two sliding plates to move. When the two blocking parts respectively move into the two slots, the channels of the two through pipes are closed; when the two communicating parts respectively move into the two slots, the channels of the two through pipes are opened.

[0014] A further technical solution of the present invention is that the transmission member includes a connecting plate fixedly arranged with the two sliding plates, and a receiving plate corresponding to the intake end of the safety valve is arranged on the connecting plate.

[0015] A further technical solution of the present invention is that the transmission member includes two connecting rods respectively hinged to the two sliding plates. One ends of the two connecting rods are hinged with a receiving plate corresponding to the intake end of the safety valve. A guide hole is opened on the receiving plate, and a guide rod is slidably connected to the inner wall of the guide hole.

[0016] A further technical solution of the present invention is that the receiving plate is in a concave arc shape with an opening facing the intake end of the safety valve.

[0017] A further technical solution of the present invention is that the heat insulation cavity is set to be vacuum.

[0018] A further technical solution of the present invention is that the elastic member is a rubber band.

[0019] A further technical solution of the present invention is that a first material pipe is hermetically connected to the LNG storage cavity and leads to the outside of the tank.

[0020] A further technical solution of the present invention is that a second material pipe is hermetically connected to the LNG storage cavity and leads to the outside of the tank.

[0021] A further technical solution of the present invention is that a bracket is provided at the bottom of the tank body.

[0022] The beneficial effects of the present invention are as follows: By setting up the cooperation of the tank body, the heat insulation cavity, the heat dissipation cavity, the LNG storage cavity, two through pipes, the liquid nitrogen tank, the switch structure, the elastic member and the safety valve, when in use, LNG is placed into the LNG storage cavity in the tank body. When the heat outside the LNG storage tank enters the LNG storage tank, it will cause the volatilization of LNG, thus increasing the air pressure in the storage tank. Once the air pressure exceeds the safety value of the safety valve, the safety valve opens, and the gas is discharged from the air outlet end of the safety valve and pushes the switch structure to open the channels of the two through pipes. Furthermore, the liquid nitrogen in the liquid nitrogen tank will enter the heat dissipation cavity through the through pipe connected to it. Since the boiling point of liquid nitrogen is lower than that of LNG, the liquid nitrogen will absorb the heat of LNG and volatilize, and then be discharged along the other through pipe, thereby achieving the purpose of cooling LNG, inhibiting the volatilization of LNG and suppressing the increase of the air pressure in the storage tank, and reducing the risk of tank explosion. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic structural diagram of a specific embodiment of the present invention.

[0024] Figure 2 is a cross-sectional view of a specific embodiment of the present invention.

[0025] Figure 3 is a specific embodiment of the present invention Figure 2 schematic enlarged structural diagram at A in

[0026] Figure 4 is a schematic structural diagram of the tank body of a specific embodiment of the present invention.

[0027] Figure 5 is an exploded view of the outer tank, the middle tank and the inner tank of a specific embodiment of the present invention.

[0028] Figure 6 is a schematic structural diagram of an embodiment of the transmission member of a specific embodiment of the present invention.

[0029] Figure 7 is a schematic structural diagram of another embodiment of the transmission member of a specific embodiment of the present invention.

[0030] In the figure: 1 - tank body, 101 - outer tank, 102 - middle tank, 103 - inner tank, 104 - connecting strip, 2 - heat insulation cavity, 3 - heat dissipation cavity, 4 - LNG storage cavity, 5 - through pipe, 6 - liquid nitrogen tank, 7 - switch structure, 701 - slot, 702 - sliding plate, 7021 - blocking part, 7022 - communicating part, 703 - transmission member, 7031 - connecting plate, 7032 - receiving plate, 7033 - connecting rod, 7034 - guide rod, 8 - elastic member, 9 - safety valve, 10 - first material pipe, 11 - second material pipe, 12 - bracket. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present disclosure clearer, the following will clearly and completely describe the technical solutions of the embodiments of the present disclosure in conjunction with the accompanying drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present disclosure without creative efforts belong to the scope of protection of the present disclosure.

[0032] As Figure 1-7 shown, in an embodiment of the present invention, an LNG vacuum cryogenic liquid storage tank includes:

[0033] Referring to Figure 1 , Figure 2 and Figure 5 shown, a tank body 1, the tank body 1 includes an outer tank 101, a middle tank 102, an inner tank 103, and a plurality of connecting bars 104. The outer tank 101 is arranged on the outermost side of the tank body 1, the middle tank 102 is arranged between the outer tank 101 and the inner tank 103. An insulation cavity 2 is formed between the outer tank 101 and the middle tank 102. The insulation cavity 2 can isolate heat and keep the space inside the middle tank 102 warm. In this embodiment, the insulation cavity 2 is set to be vacuum. In some other embodiments, the insulation cavity 2 is filled with heat insulation cotton. A heat dissipation cavity 3 is formed between the middle tank 102 and the inner tank 103, and a storage cavity 4 is formed inside the inner tank 103. The plurality of connecting bars 104 are respectively fixedly arranged between the outer tank 101 and the middle tank 102, and between the middle tank 102 and the inner tank 103, for respectively supporting the middle tank 102 and the inner tank 103. A first material pipe 10 is hermetically connected to the LNG storage cavity 4 and leads to the outside of the tank body 1. A second material pipe 11 is hermetically connected to the LNG storage cavity 4 and leads to the outside of the tank body 1. The first material pipe 10 and the second material pipe 11 can respectively serve as channels for LNG inlet and discharge, facilitating use;

[0034] Referring to Figure 2 shown, two through pipes 5 are hermetically connected to the heat dissipation cavity 3 and lead to the outside of the tank body 1, forming two channels for the heat dissipation cavity 3 to communicate with the outside;

[0035] Referring to Figure 1 and Figure 2 shown, a liquid nitrogen tank 6 is hermetically connected to one of the through pipes 5 for containing liquid nitrogen;

[0036] Referring to Figure 1 shown, a switch structure 7 is arranged on the tank body 1 and the two through pipes 5 for opening or closing the channels of the two through pipes 5;

[0037] Referring to Figure 4As shown, an elastic member 8 is disposed on the switch structure 7 and the tank body 1. The elastic force of the elastic member 8 is used to drive the switch structure 7 to close the channels of the two through pipes 5. In this embodiment, the elastic member 8 is a rubber band. In some other embodiments, the elastic member 8 is a tension spring;

[0038] Reference Figure 2 、 Figure 4 and Figure 5 As shown, a safety valve 9. When the air pressure in the tank body 1 exceeds the safety value of the safety valve, the safety valve 9 will open, so that the gas in the LNG storage cavity 4 is discharged and released, thereby reducing the air pressure in the LNG storage cavity 4. The intake end of the safety valve 9 is hermetically connected to the LNG storage cavity 4. The outlet end of the safety valve 9 extends outside the tank body 1 and corresponds to the switch structure 7. The gas released by the safety valve 9 can push the switch structure 7 to open the channels of the two through pipes 5;

[0039] A bracket 12 is provided at the bottom of the tank body 1. The bracket 12 can support and lift the tank body 1 to improve the stability of the tank body 1;

[0040] In this embodiment, the switch structure 7 includes two slots 701 respectively opened on the two through pipes 5. The inner walls of the two slots 701 are both slidably connected with sliding plates 702. A blocking portion 7021 and a communicating portion 7022 are provided on each of the two sliding plates 702 (as shown in Figure 3 ). A transmission member 703 corresponding to the intake end of the safety valve 9 is provided between the two sliding plates 702. The gas released by the safety valve 9 can push the transmission member 703 to move. The movement of the transmission member 703 can drive the two sliding plates 702 to move. When the two blocking portions 7021 respectively move into the two slots 701, the channels of the two through pipes 5 are closed; when the two communicating portions 7022 respectively move into the two slots 701 and the two communicating portions 7022 are respectively communicated with the two through pipes 5, the channels of the two through pipes 5 are opened;

[0041] Reference Figure 6 As shown, in this embodiment, the transmission member 703 includes a connecting plate 7031 fixedly arranged with the two sliding plates 702. A receiving plate 7032 corresponding to the intake end of the safety valve 9 is provided on the connecting plate 7031. In this embodiment, the receiving plate 7032 is in a concave arc shape with an opening facing the intake end of the safety valve 9, which can better receive the impact force of the gas ejected from the intake end of the safety valve 9. The gas ejected by the safety valve 9 will push the receiving plate 7032 to move. The movement of the receiving plate 7032 drives the two sliding plates 702 to move through the connecting plate 7031, and the two communicating portions 7022 are respectively communicated with the two through pipes 5, so as to open the channels of the two through pipes 5.

[0042] In this specific embodiment, during use, LNG is placed into the LNG storage cavity 4 within the tank body 1. When heat outside the LNG storage tank enters the LNG storage tank, it will cause the volatilization of LNG, thereby increasing the air pressure within the storage tank. Once the air pressure exceeds the safety value of the safety valve 9, the safety valve 9 opens, and the gas is discharged from the air outlet end of the safety valve 9 and pushes the switch structure 7 to open the channels of the two through pipes 5. Furthermore, the liquid nitrogen in the liquid nitrogen tank 6 will enter the heat dissipation cavity 3 through the through pipe 5 connected to it. Since the boiling point of liquid nitrogen is lower than that of LNG, the liquid nitrogen will absorb the heat of LNG and volatilize, and then be discharged along the other through pipe 5, thereby achieving the purpose of cooling LNG, inhibiting the volatilization of LNG and suppressing the increase in the air pressure within the storage tank, and reducing the risk of tank explosion.

[0043] Reference Figure 7 As shown, as another embodiment of the transmission member 703, the difference lies in the structure of the transmission member 703. In this embodiment, the transmission member 703 includes two connecting rods 7033 respectively hinged to the two sliding plates 702. Both of the two sliding plates 702 are hinged to the two connecting rods 7033 through hinges. One end of the two connecting rods 7033 is hinged with a receiving plate 7032 corresponding to the air inlet end of the safety valve 9. Both of the two connecting rods 7033 are hinged to the receiving plate 7032 through hinges. A guide hole is formed on the receiving plate 7032, and a guide rod 7034 is slidably connected to the inner wall of the guide hole. During use, the gas ejected from the safety valve 9 will push the receiving plate 7032 to move along the guide rod 703. The receiving plate 7032 will drive the included angle formed by the two connecting rods 7033 to shrink, and then drive the two sliding plates 702 to approach each other, so that the two communicating parts 7022 are respectively communicated with the two through pipes 5, thereby realizing the opening of the channels of the two through pipes 5.

Claims

1. An LNG vacuum cryogenic liquid storage tank, characterized in that, Including: A tank body (1), which is successively divided into a heat insulation cavity (2), a heat dissipation cavity (3) and an LNG storage cavity (4) from outside to inside; Two through pipes (5), which are hermetically connected to the heat dissipation cavity (3) and lead to the outside of the tank body (1); A liquid nitrogen tank (6), which is hermetically connected to one of the through pipes (5) and is used for containing liquid nitrogen; A switch structure (7), which is arranged on the tank body (1) and the two through pipes (5) and is used for opening or closing the channels of the two through pipes (5); An elastic member (8), which is arranged on the switch structure (7) and the tank body (1) and is used for driving the switch structure (7) to close the channels of the two through pipes (5); A safety valve (9), the intake end of the safety valve (9) is hermetically connected to the LNG storage cavity (4), the outlet end of the safety valve (9) extends to the outside of the tank body (1) and corresponds to the switch structure (7), and the gas released by the safety valve (9) can push the switch structure (7) to open the channels of the two through pipes (5); The switch structure (7) includes two slots (701) respectively opened on the two through pipes (5), the inner walls of the two slots (701) are both slidably connected with sliding plates (702), a blocking part (7021) and a communicating part (7022) are arranged on each of the two sliding plates (702), a transmission member (703) corresponding to the intake end of the safety valve (9) is arranged between the two sliding plates (702), the gas released by the safety valve (9) can push the transmission member (703) to move, and the movement of the transmission member (703) can drive the two sliding plates (702) to move. When the two blocking parts (7021) respectively move into the two slots (701), the channels of the two through pipes (5) are closed; When the two communicating parts (7022) respectively move into the two slots (701), the channels of the two through pipes (5) are opened. The transmission member (703) includes a connecting plate (7031) fixedly arranged with the two sliding plates (702), a receiving plate (7032) corresponding to the intake end of the safety valve (9) is arranged on the connecting plate (7031), and the receiving plate (7032) is in the shape of a concave arc with an opening facing the intake end of the safety valve (9).

2. The LNG vacuum cryogenic liquid storage tank according to claim 1, characterized in that, The transmission member (703) includes two connecting rods (7033) respectively hinged to the two sliding plates (702), a receiving plate (7032) corresponding to the intake end of the safety valve (9) is hinged to one end of the two connecting rods (7033), a guide hole is opened on the receiving plate (7032), and a guide rod (7034) is slidably connected to the inner wall of the guide hole.

3. The LNG vacuum cryogenic liquid storage tank according to claim 1, characterized in that, The inside of the heat insulation cavity (2) is set to be vacuum.

4. The LNG vacuum cryogenic liquid storage tank according to claim 1, characterized in that, The elastic member (8) is a rubber band.

5. The LNG vacuum cryogenic liquid storage tank according to claim 1, characterized in that, A first material pipe (10) is hermetically connected to the LNG storage cavity (4) and leads to the outside of the tank body (1).

6. The LNG vacuum cryogenic liquid storage tank according to claim 5, characterized in that, A second material pipe (11) is hermetically connected to the LNG storage cavity (4) and leads to the outside of the tank body (1).

7. The LNG vacuum cryogenic liquid storage tank according to claim 1, characterized in that, A bracket (12) is arranged at the bottom of the tank body (1).

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