An LNG storage device with recovery function

Abstract

The present invention discloses an LNG storage device with a recovery function, which relates to the technical field of LNG storage, and comprises: a sealing seat, on which an outer tank body is fixed; an inner tank body, which is fixed on the sealing seat and located inside the outer tank body, and a sealing cover is provided on the upper part of the inner tank body, and a through groove is opened in the middle of the sealing cover; a micro-deformable plate, which is sealed and connected in the through groove by a sealing elastic ring; a downward pressure buffer component, which is connected to the inner top of the outer tank body and is used to provide downward pressure buffer for the micro-deformable plate; a suction pipe, an air suction pipe, an air suction pump, a first pipe body, a heat exchange pipe, a second pipe body, a refrigeration component, and a liquid return pipe, which are connected in series in sequence and form a loop, wherein the suction pipe is located at the inner top of the inner tank body, and the heat exchange pipe is located at the inner bottom of the inner tank body; by recovering and liquefying BOG, the reuse of LNG resources is realized, and the waste of resources is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of LNG storage, in particular to an LNG storage device with a recovery function. Background Art

[0002] LNG is produced by cooling natural gas to a liquid state under cryogenic conditions. This transformation greatly reduces the volume, making LNG an ideal choice for long-distance transportation and large-scale storage. However, this storage condition is also accompanied by a series of technical challenges, including how to build an efficient insulation system to reduce heat penetration, how to effectively prevent LNG from gasification losses to maintain storage efficiency, and how to ensure the safety of operations throughout the process.

[0003] Although traditional LNG storage devices have met the basic needs of the industry to a certain extent, their limitations have gradually emerged in practical applications. These shortcomings not only limit the improvement of LNG storage efficiency, but also restrict the pace of the LNG industry's expansion into a wider range of fields.

[0004] Specifically, in traditional LNG storage devices, due to the imperfect recovery and treatment mechanism of boil-off gas (BOG), some BOG is directly discharged into the atmosphere. When processing BOG, existing technologies often consume a lot of energy to reduce its temperature and pressure to achieve liquefaction conditions. This not only increases operating costs, but also reduces overall energy efficiency. At the same time, due to low processing efficiency, more equipment and manpower may be required, further pushing up the overall cost. This, to a certain extent, limits the application of LNG storage devices in a wider range of fields.

[0005] In addition, the LNG storage devices in the prior art are often difficult to maintain stable operation when the gas pressure fluctuates. This not only affects the storage quality of LNG, but also may shorten the service life of the storage device. The problem of poor system stability mainly stems from the lack of adaptability to gas pressure changes and the lack of effective buffering and regulation mechanisms.

[0006] Therefore, it is necessary to provide an LNG storage device with a recovery function to solve the above problems. Summary of the invention

[0007] In order to solve the above problems, the present invention provides the following technical solution: an LNG storage device with a recovery function, comprising:

[0008] A sealing seat, on which the outer tank body is fixed;

[0009] An inner tank body is fixed on the sealing seat and is located inside the outer tank body. A sealing cover is provided on the upper part of the inner tank body, and a through groove is provided in the middle of the sealing cover.

[0010] A micro-deformable plate, which is sealed and connected in the through groove by a sealing elastic ring;

[0011] A downward pressure buffer assembly, which is connected to the inner top of the outer tank body and is used to provide downward pressure buffering for the micro-deformation plate;

[0012] A suction pipe, an air suction pipe, an air suction pump, a first pipe body, a heat exchange pipe, a second pipe body, a refrigeration component, and a liquid return pipe are sequentially connected in series and form a loop, wherein the suction pipe is located at the inner top of the inner tank body, and the heat exchange pipe is located at the inner bottom of the inner tank body;

[0013] Wherein, a first valve body is provided on the air intake pipe;

[0014] A second valve body is provided on the liquid return pipe;

[0015] The suction tube is provided with micropores.

[0016] Further, preferably, the elastic modulus of the micro-deformable plate is smaller than the elastic modulus of the sealing elastic ring.

[0017] Further, preferably, the downward pressure buffer assembly comprises:

[0018] A base, the bottom of which is connected to the micro-deformable plate by a connecting frame;

[0019] A plurality of hangers distributed at intervals, one end of each hanger being connected to the base, and the other end of each hanger being connected to the inner top of the outer tank body by a steel wire rope;

[0020] A plurality of legs distributed at intervals, one end of which is hinged to the base and the other end of which is rotatably provided with a roller;

[0021] A return spring is connected between the legs and the base.

[0022] Further, preferably, the refrigeration component comprises:

[0023] A refrigeration tank, the bottom of which is connected to the second tube body, and the top of which is connected to the liquid return pipe;

[0024] A liquid pump, the liquid inlet of which is connected to the liquid outlet of the refrigerator, and the liquid outlet of the liquid pump is connected to the refrigeration tank;

[0025] A micro tank is connected to the liquid inlet end of the refrigerator, and liquid natural gas is contained in the micro tank.

[0026] Furthermore, preferably, a temperature measuring instrument is also provided on one side of the refrigeration tank.

[0027] Further, as a preference, a base is arranged below the sealing seat, a plurality of partition plates are connected between the sealing seat and the base, a plurality of grid spaces are formed between the plurality of partition plates, and a support assembly is arranged in each grid space for supporting the sealing seat.

[0028] Further, preferably, the support assembly comprises:

[0029] A trough body, which is fixed on the base, and a clamping shoulder is provided at the opening of the trough body;

[0030] A piston rod, one end of which is sealingly slidably connected to the groove body, and the other end of which is sealingly slidably extended out of the shoulder so as to be connected to the sealing seat;

[0031] The air supply hole is opened at the bottom of the tank body, and the air supply hole has a first one-way valve and a hole plug.

[0032] Further, as a preference, an elliptical ring frame is fixed to the inner bottom of the trough body, a plurality of springs are installed in the middle of the elliptical ring frame, and a plurality of ventilation holes are opened in the middle of the elliptical ring frame.

[0033] Furthermore, preferably, the length of the heat exchange tube satisfies: being able to accommodate the gas generated by the LNG storage device at a full load state and a 5% evaporation rate.

[0034] Compared with the prior art, the present invention provides an LNG storage device with a recovery function, which has the following beneficial effects:

[0035] The present invention processes BOG through two stages of precooling and refrigeration, thereby improving liquefaction efficiency, reducing processing time, realizing BOG recovery, reducing more energy consumption and emission costs caused by processing BOG, and further reducing overall operating costs.

[0036] In the present invention, the micro-deformation plate and the downward pressure buffer assembly cooperate with each other so that the LNG storage device can maintain stable operation when the gas pressure changes, thereby enhancing the stability and durability of the LNG storage device.

[0037] The present invention can effectively protect the entire LNG storage device from damage and extend its service life through a shock-absorbing and buffering mechanism combining gas and springs. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a schematic diagram of the structure of an LNG storage device with a recovery function;

[0039] Figure 2 for Figure 1 The right half of the enlarged structural diagram;

[0040] Figure 3 for Figure 1 The enlarged structural diagram at A in the middle;

[0041] Figure 4 A schematic diagram of the structure of a support assembly in an LNG storage device with a recovery function;

[0042] In the figure: 1. base; 2. partition plate; 3. support assembly; 4. outer tank body; 5. inner tank body; 6. sealing elastic ring; 7. micro-deformation plate; 8. downward pressure buffer assembly; 9. suction pipe; 10. air intake pipe; 101. first valve body; 11. suction pump; 12. first tube body; 13. heat exchange tube; 14. second tube body; 15. refrigeration tank; 16. liquid pump; 17. micro tank; 18. liquid return pipe; 181. second valve body; 19. refrigerator; 31. trough body; 32. shoulder; 33. piston rod; 34. air supplement hole; 35. vent hole; 36. spring; 81. base; 82. support leg; 83. roller; 84. hanger; 85. wire rope; 86. connecting frame. DETAILED DESCRIPTION

[0043] The terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned description of the drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the terms used in this way can be interchangeable under appropriate circumstances, which is merely a way of distinguishing the objects of the same attributes when describing them in the embodiments of the present application. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, so that the process, method, system, product or equipment comprising a series of units need not be limited to those units, but may include other units that are not clearly listed or inherent to these processes, methods, products or equipment.

[0044] Example: Please refer to Figure 1-Figure 4 In an embodiment of the present invention, there is provided an LNG storage device with a recovery function, comprising:

[0045] A sealing seat, on which the outer tank body 4 is fixed;

[0046] The inner tank body 5 is fixed on the sealing seat and is located inside the outer tank body 4. A sealing cover is provided on the upper part of the inner tank body 5. A through groove is provided in the middle of the sealing cover. Of course, a gap is reserved between the inner tank body 5 and the outer tank body 4 for placing a temperature control component / temperature control liquid / protective component. The specific structures of the inner tank body 5 and the outer tank body 4 are not described in detail here.

[0047] A micro-deformation plate 7, which is sealed and connected in the through groove by a sealing elastic ring 6;

[0048] A downward pressure buffer assembly 8, which is connected to the inner top of the outer tank body 4 and is used to provide downward pressure buffering for the micro-deformation plate 7;

[0049] A suction pipe 9, an air intake pipe 10, an air pump 11, a first tube body 12, a heat exchange tube 13, a second tube body 14, a refrigeration assembly, and a liquid return pipe 18 are sequentially connected in series and form a loop, wherein the suction pipe 9 is located at the inner top of the inner tank body 5, and the heat exchange tube 13 is located at the inner bottom of the inner tank body 5;

[0050] Wherein, the air intake pipe 10 is provided with a first valve body 101;

[0051] The liquid return pipe 18 is provided with a second valve body 181;

[0052] The suction tube 9 is provided with micropores;

[0053] The length of the heat exchange tube 13 is sufficient to accommodate the gas generated by the LNG storage device at a full load state and a 5% evaporation rate.

[0054] It is important to note that no matter what measures are taken, evaporation in LNG storage devices cannot be completely avoided. The gas produced by evaporation (BOG, Boil Off Gas, flash gas) is an inevitable part of the LNG storage process.

[0055] In this embodiment, by providing a suction pipe 9, an air intake pipe 10, an air pump 11, a first tube body 12, a heat exchange tube 13, a second tube body 14, a refrigeration assembly, and a liquid return pipe 18 which are sequentially connected in series and form a loop, this problem can be effectively addressed. Specifically, during implementation, the following steps are included:

[0056] S1. When LNG naturally evaporates in the inner tank 5 to produce BOG, these gases will gather at the top of the inner tank 5.

[0057] S2. Start the first valve body 101 and the vacuum pump 11 (while closing the second valve body 181 and the refrigeration assembly), and suck BOG through the suction pipe 9 and the micropores thereon; the collected BOG is sent to the heat exchange pipe 13, and is pre-cooled by the low-temperature LNG in the inner tank body 5 to reduce its temperature.

[0058] S4. After precooling is completed, the first valve body 101 and the vacuum pump 11 are closed, and the second valve body 181 and the refrigeration component are opened at the same time.

[0059] The refrigeration component further reduces the temperature of the BOG to reach the liquefaction point, and the BOG flows back to the suction pipe 9 through the return pipe 18 and is sprayed into the inner tank body 5, thereby realizing the recovery and utilization of the BOG.

[0060] Among them, by recovering and liquefying BOG, the reuse of LNG resources is achieved, resource waste is reduced, and the environmental pollution that may be caused by directly discharging BOG into the atmosphere is avoided.

[0061] In addition, in this embodiment, the micro-deformation plate 7 and the downward pressure buffer assembly 8 cooperate with each other to enable the LNG storage device to adapt to the changes in the air pressure in the inner tank body 5. As BOG is generated and collected, the air pressure in the inner tank body 5 will rise, and the micro-deformation plate 7 will be slightly deformed under the action of the air pressure, and the downward pressure buffer assembly 8 will provide buffering to prevent the sudden change in air pressure from causing damage to the LNG storage device.

[0062] In this embodiment, the elastic modulus of the micro-deformable plate 7 is smaller than the elastic modulus of the sealing elastic ring 6 .

[0063] Among them, the sealing elastic ring 6, as a component connecting the micro-deformable plate 7 and the through groove, needs to have a high elastic modulus to ensure that it can tightly seal the through groove to prevent leakage of LNG or BOG. ​​The low elastic modulus of the micro-deformable plate 7 allows it to deform more easily when the air pressure inside the inner tank changes, so that it can adaptively adjust its shape and position to maintain a good sealing state with the sealing elastic ring 6. This design ensures that the sealing performance can be maintained even in the case of air pressure fluctuations.

[0064] In this embodiment, the downward pressure buffer assembly 8 includes:

[0065] The base 81, the bottom of which is connected to the micro-deformable plate 7 by a connecting frame 86;

[0066] A plurality of hangers 84 are arranged at intervals, one end of each hanger 84 is connected to the base 81, and the other end of each hanger 84 is connected to the inner top of the outer tank body 4 by a steel wire rope 85;

[0067] A plurality of legs 82 are spaced apart, one end of which is hinged to the base 81 and the other end of which is rotatably provided with a roller 83;

[0068] A return spring is connected between the support leg 82 and the base 81 .

[0069] The base 81 is tightly connected to the micro-deformable plate 7 via the connecting frame 86, so that when the micro-deformable plate 7 is deformed by the air pressure inside the inner tank, the base 81 will move along with it and provide buffering energy through the reset spring.

[0070] In addition, one end of the leg 82 is hinged to the base 81, which allows the leg to deflect freely within a certain range. The other end is rotatably provided with a roller 83, which contacts the inner wall of the outer tank 4, further increasing the flexibility of the leg movement. When the base 81 moves upward, the leg 82 will deflect accordingly, and the roller 83 will roll on the inner wall, reducing friction and resistance.

[0071] Therefore, in the case of a sudden change in air pressure, the downward pressure buffer assembly 8 can stably support the micro-deformable plate 7 and slow down its movement speed, thereby reducing the safety risks caused by air pressure fluctuations.

[0072] In this embodiment, the refrigeration component includes:

[0073] A refrigeration tank 15, the bottom of which is connected to the second tube body 14, and the top of the refrigeration tank 15 is connected to the liquid return pipe 18. In addition, a second one-way valve is provided at a position of the second tube body 14 close to the refrigeration tank 15, and the second one-way valve prevents the fluid in the refrigeration tank 15 from flowing back to the heat exchange tube 13;

[0074] A liquid pump 16, whose liquid inlet end is connected to the liquid outlet end of the refrigerator 19, and the liquid outlet end of the liquid pump 16 is connected to the refrigeration tank 15;

[0075] The micro tank 17 is connected to the liquid inlet end of the refrigerator 19, and the micro tank 17 contains liquid natural gas.

[0076] In addition, a temperature measuring instrument is also provided on one side of the refrigeration tank 15 .

[0077] During implementation, the pre-cooled BOG enters the second pipe body 14 and flows into the refrigeration tank 15 .

[0078] The liquefied natural gas in the micro tank 17 is sent to the refrigerator 19 for cooling.

[0079] The cooled liquefied natural gas is pumped into the refrigeration tank 15 by the liquid pump 16 and mixed with the BOG to further reduce the temperature of the BOG.

[0080] As the temperature decreases, BOG gradually liquefies.

[0081] The liquefied LNG is returned to the LNG storage system through the liquid return pipe 18 to achieve the recovery and utilization of BOG.

[0082] In addition, a thermometer is installed on one side of the refrigeration tank 15 to monitor the temperature in the refrigeration tank 15 in real time to ensure that the BOG can be effectively cooled to a liquefied state. The data from the thermometer can be used to adjust the working state of the refrigerator 19 and the liquid pump 16 to maintain the best refrigeration effect.

[0083] In this embodiment, a base 1 is arranged below the sealing seat, and a plurality of partition plates 2 are connected between the sealing seat and the base 1, and a plurality of grid spaces are formed between the plurality of partition plates 2. A support assembly 3 is arranged in each grid space for supporting the sealing seat and providing a certain amount of shock absorption and buffering for the entire LNG storage device, wherein the base 1 is the supporting foundation of the entire LNG storage device, and its stability is of vital importance. The design of the base should take into account the bearing capacity of the ground and possible geological conditions to ensure that it will not sink or deform during long-term use, wherein a plurality of partition plates 2 are arranged between the base 1 and the sealing seat to form a plurality of grid spaces. These grid spaces not only help to disperse the weight and improve the overall stability, but also provide an installation position for the support assembly 3, making the shock absorption and buffering effect more uniform.

[0084] Specifically, the support assembly 3 includes:

[0085] A slot body 31 is fixed on the base 1, and a clamping shoulder 32 is provided at the opening of the slot body 31;

[0086] A piston rod 33, one end of which is sealingly slidably connected to the groove body 31, and the other end of which is sealingly slidably extended out of the shoulder 32 so as to be connected to the sealing seat;

[0087] The air supply hole 34 is opened at the bottom of the groove body 31, and the air supply hole 34 has a first one-way valve and a hole plug, that is, the support component 3 mainly relies on gas as the basis of shock absorption and buffering.

[0088] In addition, an elliptical ring frame is fixed to the inner bottom of the tank body 31 , a plurality of springs 36 are installed in the middle of the elliptical ring frame, and a plurality of vent holes 35 are opened in the middle of the elliptical ring frame, so as to allow the gas to flow freely in the tank body 31 .

[0089] Then, when the LNG storage device is subjected to external vibration or impact, the sealing seat will drive the piston rod 33 to move slightly up and down in the groove body 31. At this time, the gas in the groove body 31 will be compressed or expanded, thereby absorbing and dispersing the impact energy. At the same time, the spring 36 on the elliptical ring frame will also deform to further absorb the impact energy. This shock-absorbing and buffering mechanism combining gas and spring can effectively protect the entire LNG storage device from damage and extend its service life.

[0090] In addition, the oval ring frame has good structural stability. Its oval shape can disperse stress more effectively when under pressure, reduce local stress concentration, and thus extend the service life of the component.

[0091] What is described above is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An LNG storage device with a recovery function, characterized in that: include: A sealing seat, on which the outer tank body (4) is fixed; an inner tank body (5) fixed on the sealing seat and located inside the outer tank body (4), and a sealing cover is provided above the inner tank body (5), a through groove being provided in the middle of the sealing cover; A micro-deformation plate (7) which is sealed and connected in the through groove by means of a sealing elastic ring (6); A downward pressure buffer assembly (8), which is connected to the inner top of the outer tank body (4) and is used to provide downward pressure buffering for the micro-deformation plate (7); A suction pipe (9), an air intake pipe (10), an air pump (11), a first tube body (12), a heat exchange tube (13), a second tube body (14), a refrigeration component, and a liquid return pipe (18) are sequentially connected in series to form a loop, wherein the suction pipe (9) is located at the inner top of the inner tank body (5), and the heat exchange tube (13) is located at the inner bottom of the inner tank body (5); Wherein, a first valve body (101) is provided on the air intake pipe (10); The liquid return pipe (18) is provided with a second valve body (181); The suction tube (9) is provided with micropores; The downward pressure buffer assembly (8) comprises: A base (81), the bottom of which is connected to the micro-deformable plate (7) by a connecting frame (86); a plurality of hangers (84) distributed at intervals, one end of each hanger (84) being connected to the base (81), and the other end of each hanger (84) being connected to the inner top of the outer tank body (4) by a steel wire rope (85); A plurality of legs (82) distributed at intervals, one end of which is hinged to the base (81) and the other end of which is rotatably provided with a roller (83); a return spring connected between the supporting leg (82) and the base (81); A base (1) is arranged at intervals below the sealing seat, a plurality of partition plates (2) are connected between the sealing seat and the base (1), a plurality of grid spaces are formed between the plurality of partition plates (2), and a support assembly (3) is arranged in each grid space for supporting the sealing seat; The support assembly (3) comprises: A trough body (31) fixed on the base (1), and a clamping shoulder (32) is provided at the opening of the trough body (31); A piston rod (33), one end of which is sealingly slidably connected to the groove body (31), and the other end of which is sealingly slidably extended out of the clamping shoulder (32) so as to be connected to the sealing seat; An air supply hole (34) is provided at the bottom of the tank body (31), and the air supply hole (34) has a first one-way valve and a hole plug; An elliptical ring frame is fixed to the inner bottom of the trough body (31), a plurality of springs (36) are installed in the middle of the elliptical ring frame, and a plurality of ventilation holes (35) are opened in the middle of the elliptical ring frame.

2. The LNG storage device with recovery function according to claim 1, characterized in that: The elastic modulus of the micro-deformation plate (7) is smaller than the elastic modulus of the sealing elastic ring (6).

3. The LNG storage device with recovery function according to claim 1, characterized in that: The refrigeration assembly comprises: A refrigeration tank (15), the bottom of which is connected to the second tube body (14), and the top of which is connected to the liquid return pipe (18); A liquid pump (16), the liquid inlet end of which is connected to the liquid outlet end of the refrigerator (19), and the liquid outlet end of the liquid pump (16) is in communication with the refrigeration tank (15); A micro tank (17) is connected to the liquid inlet end of the refrigerator (19), and liquid natural gas is contained in the micro tank (17).

4. The LNG storage device with recovery function according to claim 3 is characterized in that: A temperature measuring instrument is also provided on one side of the refrigeration tank (15).

5. The LNG storage device with recovery function according to claim 1, characterized in that: The length of the heat exchange tube (13) satisfies the requirement of being able to accommodate the gas generated by the LNG storage device in a fully loaded state with a 5% evaporation rate.

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