LNG (Liquefied Natural Gas) storage tank outer coil pipe cold insulation device utilizing BOG (Boil Off Gas) cold energy

Abstract

The utility model relates to the technical field of energy recovery, in particular to an LNG (Liquefied Natural Gas) storage tank outer coil pipe cold insulation device utilizing BOG (Boil Off Gas) cold energy. According to the technical scheme, the LNG storage tank comprises an LNG storage tank and a storage tank outer coil pipe, and further comprises an inner tank, an outer tank and a cold insulation material. The LNG storage tank, the inner tank, the outer tank, the cold insulation material, the storage tank outer coil pipe, the second vertical pipe, the annular pipe, the fins and other structures are matched, cold energy of BOG in the LNG storage tank is recycled and used for preventing cold loss of LNG in the storage tank, and more BOG is prevented from being generated due to permeation of heat in the atmospheric environment outside the storage tank. Meanwhile, the coil pipes are evenly distributed on the outer tank of the LNG storage tank and connected through the fins, the BOG is stored in the coil pipes, cold energy of the BOG is diffused to the surface of the outer tank through the fins, and the situation that due to the fact that the outer tank is heated, heat of outside air permeates into the tank, and more BOG is generated is prevented.

Description

Technical Field

[0001] The utility model relates to the technical field of energy recovery, in particular to an external coil cold preservation device for an LNG storage tank utilizing BOG cold energy. Background Art

[0002] At present, when the LNG storage tank stores liquefied natural gas (LNG) at -162℃, the heat from the external environment will be transmitted into the tank through the tank wall, tank top and tank bottom, causing the temperature of the LNG in the tank to rise continuously after absorbing heat, thus changing from liquid to gaseous boil-off gas (BOG), causing the LNG in the tank to stratify and roll over. The generation of BOG in the LNG storage tank will cause the operating pressure in the tank to exceed the safe range, so BOG must be discharged to the outside through a pipeline to ensure the safety of the LNG storage tank. When BOG is released from the LNG storage tank, its temperature is -162℃, while the gas transmission temperature required to enter the downstream pipeline is generally 15℃. In order to meet the downstream gas transmission temperature, BOG will be heated by a vaporizer. In this process, the cold energy stored in BOG will be abandoned, resulting in a large amount of waste of BOG cold energy. LNG storage tanks need to be kept cold to reduce the generation of BOG, while the -162℃ BOG released from the tank must be heated to meet the downstream gas transmission temperature. For this reason, it is considered to recover the cold energy of BOG to maintain the low temperature environment of the LNG storage tank. In addition, the ring pipe installed on the outer coil cooling device of the LNG storage tank is used to provide heat and cold insulation effects to prevent the medium in the pipeline from overheating or overcooling, thereby ensuring that the fluid remains within the required temperature range during transportation. However, when using mechanical equipment, transport vehicles or other mobile equipment, if the ring pipe is accidentally hit, it will cause collision damage. Utility Model Content

[0003] The utility model aims to solve the problems existing in the background technology and proposes an external coil cold preservation device for LNG storage tanks using BOG cold energy, which recovers BOG cold energy to maintain the low temperature environment of the LNG storage tank and reduce the generation of BOG in the tank.

[0004] The technical solution of the utility model is: an LNG storage tank outer coil cold preservation device utilizing BOG cold energy, comprising an LNG storage tank and an outer coil of the storage tank, and also comprising: the LNG storage tank comprising an inner tank, an outer tank and a cold preservation material; the outer coil of the storage tank comprising a second riser, an annular tube and fins; a protective mechanism installed on the outer tank for quickly opening to sheath the annular tube.

[0005] Optionally, a second riser and a third riser are symmetrically distributed on both sides of the outer tank, and the annular tube is a group of pipes equidistantly distributed along the annular direction of the outer tank, each of the annular tube surrounds the outer tank in a circle and is connected to the second riser and the third riser at both radial ends, and the annular tubes are connected by fin welding, and the fins are welded at the radial positions at both ends of the annular tube, and there is a gap between the fins and the surface of the outer tank.

[0006] Optionally, a first riser is provided at the top of the inner tank, a top pipe connected to the top of the first riser is provided on the upper surface of the inner tank, a safety pressure relief valve is provided on the top pipe, a horizontal pipe is fixedly connected to the top of the third riser, one end of the horizontal pipe away from the third riser is fixedly connected to the top pipe, and a shut-off valve is provided at the bottom of the second riser.

[0007] Optionally, the protective mechanism includes an arc-shaped sticking rod mounted on the top of the outer tank, with support plates fixedly connected to both ends of the arc-shaped sticking rod, a pair of fixed arc-shaped baffles fixedly connected to the bottom ends of the support plates, a plurality of linearly arranged telescopic arc-shaped baffles are provided at the bottom of the fixed arc-shaped baffle, the middle parts of the telescopic arc-shaped baffles and the fixed arc-shaped baffles are provided with pushing springs for pushing the telescopic arc-shaped baffles to block the corresponding ring tubes, and strap mechanisms are provided at both ends of the arc-shaped sticking rod for quickly installing the protective mechanism on the top of the outer tank.

[0008] Optionally, the protective mechanism also includes a pair of limiting clamping rods fixedly connected to both ends of the telescopic arc baffle for clamping the corresponding upper telescopic arc baffle and the fixed arc baffle, and the bottom of one of the telescopic arc baffles is provided with a clamping rod mechanism for clamping the telescopic arc baffle to extend downward.

[0009] Optionally, the clamping rod mechanism includes a rotating seat fixedly connected to one of the telescopic arc baffles, a sleeve rod rotatably connected to the rotating seat, a telescopic plug rod movably sleeved on the bottom end of the sleeve rod, a hook groove for clamping the fixed arc baffle is provided at the bottom end of the telescopic plug rod, and a return spring for pulling the telescopic plug rod back into the sleeve rod is provided inside the sleeve rod.

[0010] Optionally, a handle is fixedly connected to the bottom end of the telescopic rod.

[0011] Optionally, the binding mechanism includes a first connecting strap and a second connecting strap connected to both ends of the arc-shaped stick rod, and the first connecting strap and the second connecting strap are both provided with protrusions at the opposite ends close to each other, the protrusion on the first connecting strap is inlaid with a nut, and the protrusion on the second connecting strap is rotatably connected to a screw spirally connected to the nut.

[0012] Compared with the prior art, the utility model has the following beneficial technical effects:

[0013] The utility model utilizes the coordination of structures such as LNG storage tank, inner tank, outer tank, cold insulation material, outer coil of storage tank, second riser, ring pipe and fins to recycle the cold energy of BOG in LNG storage tank and use it to protect the cold loss of LNG in storage tank, and avoid more BOG generation due to the infiltration of heat from the atmospheric environment outside the storage tank. At the same time, coils are evenly distributed on the outer tank of LNG storage tank, and the coils are connected by fins. BOG is stored in the coils, and the cold energy of BOG is diffused to the surface of the outer tank through the fins, and the outer tank is prevented from being heated to cause the heat of the outside air to infiltrate the tank, causing more BOG to be generated.

[0014] Furthermore, through the design of structures such as protective mechanisms, arc-shaped sticking rods, support plates, telescopic arc-shaped baffles and fixed arc-shaped baffles, mechanical equipment, transport vehicles or other mobile equipment can be effectively prevented from accidentally colliding with the ring pipe, thereby protecting the ring pipe itself and the surrounding equipment and environment, and reducing the occurrence of accidental damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of the structure of an external coil cold preservation device for an LNG storage tank utilizing BOG cold energy is given in the utility model;

[0016] Figure 2 for Figure 1 The enlarged schematic diagram of point A in the middle;

[0017] Figure 3 for Figure 1 Schematic diagram of the structure of the middle protection mechanism;

[0018] Figure 4 for Figure 3 The enlarged schematic diagram of point B in the middle;

[0019] Figure 5 for Figure 3 The enlarged schematic diagram of the center C;

[0020] Figure 6 It is a schematic diagram of the cross-sectional structure of the connection between the rotating seat, the sleeve rod and the telescopic plug rod.

[0021] Figure numerals: 1. first vertical pipe; 2. horizontal pipe; 3. safety pressure relief valve; 4. inner tank; 5. cold insulation material; 6. outer tank; 61. support plate; 62. fixed arc baffle; 63. telescopic arc baffle; 64. limit clamp rod; 65. push spring; 66. arc sticking rod; 7. fin; 8. second vertical pipe; 9. third vertical pipe; 10. ring pipe; 11. top pipe; 12. shut-off valve; 13. first connecting belt; 14. second connecting belt; 15. nut; 16. screw; 17. rotating seat; 18. sleeve rod; 19. telescopic plug rod; 20. hook groove; 21. handle; 22. reset spring. DETAILED DESCRIPTION

[0022] The technical solution of the present utility model will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present utility model, rather than all of the embodiments.

[0023] The components of the embodiments of the present invention generally described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention.

[0024] Based on the embodiments of the present utility model, all other embodiments obtained by ordinary technicians in the field without making any creative work shall fall within the scope of protection of the present utility model.

[0025] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0026] It should be noted that the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0027] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] Example

[0029] like Figure 1-6 As shown, the utility model proposes an LNG storage tank outer coil cold insulation device using BOG cold energy, including an LNG storage tank and an outer coil of the storage tank, and also includes: the LNG storage tank includes an inner tank 4, an outer tank 6 and a cold insulation material 5, the cold insulation material 5 is made of foam glass, and the foam glass is a porous material formed by glass powder and bubbles, which has good thermal insulation performance and chemical stability and is commonly used in the thermal insulation layer of the LNG storage tank. It can also be polyurethane foam, which is a lightweight foam material with good thermal insulation performance and is commonly used in the thermal insulation layer of the LNG storage tank; the outer coil of the storage tank includes a second riser 8, a ring tube 10 and fins 7, and the fins 7 are usually used to enhance the transfer and dissipation of heat through conduction or convection. These fins 7 can help improve the cooling efficiency of the storage tank to ensure that the liquefied natural gas (LNG) inside the storage tank is kept within an appropriate temperature range; a protective mechanism is installed on the outer tank 6 for quickly opening the ring tube 10 to cover it.

[0030] Furthermore, the second riser 8 and the third riser 9 are symmetrically distributed on both sides of the outer tank 6. The annular tube 10 is a group of pipes equidistantly distributed along the annular direction of the outer tank 6. Each annular tube 10 surrounds the outer tank 6 in a circle and is connected to the second riser 8 and the third riser 9 at both radial ends. The annular tubes 10 are welded to each other by fins 7. The fins 7 are welded at the radial positions of the two ends of the annular tube 10, and there is a gap between the fins 7 and the surface of the outer tank 6.

[0031] Among them, a first riser 1 is provided at the top of the inner tank 4, and a top pipe 11 connected to the top of the first riser 1 is provided on the upper surface of the inner tank 4. A safety pressure relief valve 3 is provided on the top pipe 11. The safety pressure relief valve 3 is a device used to protect the storage tank or container from releasing pressure under overpressure. They are key components in the storage tank system, which can ensure that the system will not have accidents due to excessive pressure under abnormal circumstances. A horizontal pipe 2 is fixedly connected to the top of the third riser 9, and the end of the horizontal pipe 2 away from the third riser 9 is fixedly connected to the top pipe 11. A shut-off valve 12 is provided at the bottom of the second riser 8. The shut-off valve 12 is a commonly used valve type used to control the flow of fluid and can quickly close or open the flow of fluid in the pipeline. It is usually used to quickly cut off the flow of fluid in an emergency to prevent accidents or perform maintenance work.

[0032] Secondly, the protective mechanism includes an arc-shaped sticking rod 66 sleeved on the top of the outer tank 6, and the arc-shaped sticking rod 66 is closely attached to the outer wall of the outer tank 6. The two ends of the arc-shaped sticking rod 66 are fixedly connected with support plates 61, and the bottom ends of a pair of support plates 61 are fixedly connected with fixed arc-shaped baffles 62. The bottom of the fixed arc-shaped baffle 62 is provided with a plurality of linearly arranged telescopic arc-shaped baffles 63 for telescopic use. The middle of the telescopic arc-shaped baffle 63 and the fixed arc-shaped baffle 62 are both provided with a push spring 65 for pushing the telescopic arc-shaped baffle 63 to block the corresponding ring tube 10. The function of the push spring 65 is to make the fixed arc-shaped baffle 62 and the plurality of telescopic arc-shaped baffles 63 arranged in sequence have the same spacing. The two ends of the arc-shaped sticking rod 66 are provided with a strap mechanism for quickly installing the protective mechanism on the top of the outer tank 6, and the function of the strap mechanism is to quickly disassemble and assemble the protective mechanism on the outer tank 6. The protective mechanism also includes a pair of limiting clamping rods 64 fixedly connected to the two ends of the telescopic arc baffle 63 for clamping the corresponding upper telescopic arc baffle 63 and the fixed arc baffle 62, and the bottom of one of the telescopic arc baffles 63 is provided with a clamping rod mechanism for clamping the telescopic arc baffle 63 to extend downward.

[0033] Furthermore, the clamping rod mechanism includes a rotating seat 17 fixedly connected to one of the telescopic arc baffles 63, a sleeve rod 18 rotatably connected to the rotating seat 17, a telescopic plug rod 19 movably sleeved at the bottom end of the sleeve rod 18, a handle 21 fixedly connected to the bottom end of the telescopic plug rod 19, a hook groove 20 for clamping the fixed arc baffle 62 is provided at the bottom end of the telescopic plug rod 19, and the function of the hook groove 20 is to make one end of the telescopic plug rod 19 clamp the fixed arc baffle 62, thereby making the protective mechanism unable to automatically deploy. A reset spring 22 for pulling the telescopic plug rod 19 back into the sleeve rod 18 is provided inside the sleeve rod 18, and the function of the reset spring 22 is to make the hook groove 20 on the telescopic plug rod 19 extend to clamp the fixed arc baffle 62.

[0034] Furthermore, the binding mechanism includes a first connecting strap 13 and a second connecting strap 14 connected to both ends of the arc-shaped sticking rod 66, and the first connecting strap 13 and the second connecting strap 14 are close to opposite ends. Both ends are provided with protrusions, and the protrusions on the first connecting strap 13 are inlaid with nuts 15, and the protrusions on the second connecting strap 14 are rotatably connected to screws 16 spirally connected to the nuts 15.

[0035] In this embodiment, when the BOG generated in the LNG storage tank is transported outward through the first riser 1, the BOG in the tank is discharged to the atmosphere through the safety pressure relief valve 3 on the first riser 1 under emergency conditions. Under normal circumstances, the BOG in the tank flows into the horizontal pipe 2 after passing through the first riser 1, and then enters the third riser 9, and then merges into the second riser 8 along the annular pipe 10. At this time, the shut-off valve 12 is closed, and the second riser 8, the third riser 9 and the annular pipe 10 become containers for storing BOG. ​​The cold energy of BOG diffuses to the fins 7, and the heat from the atmospheric environment outside the LNG storage tank is prevented from penetrating through the fins 7, which plays a role in keeping the LNG storage tank cold. When the temperature and pressure of the BOG in the second riser 8, the third riser 9 and the annular pipe 10 reach a certain limit, the shut-off valve 12 opens, and the stored BOG is output to the outside for use by downstream gas users;

[0036] When it is necessary to retract the protective mechanism from the ring tube 10, Figure 1 As shown, use your fingers to pinch the handle 21 at the bottom of the telescopic plug rod 19, and then rotate it upward with the rotating seat 17 as the center, so that the telescopic plug rod 19 drives the sleeve rod 18 to rotate nearly 180 degrees. At this time, pull the sleeve rod 18 upward, and the sleeve rod 18 drives the rotating seat 17 to drive multiple telescopic arc baffles 63 to move upward from bottom to top in sequence, through the elastic thrust of the spring 65 between the fixed arc baffle 62 and the telescopic arc baffle 63, and at the same time, the upper fixed arc baffle 62 and the telescopic arc baffle 63 are clamped in sequence through the limit clamp rod 64 on the telescopic arc baffle 63, and finally the distance between the fixed arc baffle 62 and the telescopic arc baffle 63 is minimized. At this time, the hook groove 20 on the telescopic plug rod 19 clamps the fixed arc baffle 62, and the protective mechanism can be quickly retracted and the ring tube 10 can be leaked out. When the protection needs to be activated, the above operation can be reversed. By pushing the elastic thrust of the spring 65 between the fixed arc baffle 62 and the telescopic arc baffle 63, the distance between the telescopic arc baffle 63 is automatically opened to cover the corresponding annular tube 10, which is convenient and quick.

[0037] The preferred embodiments of the utility model of the above utility model are only used to help explain the utility model. The preferred embodiments do not describe all the details in detail, nor do they limit the utility model to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the utility model, so that technicians in the relevant technical field can well understand and use the utility model. The utility model is limited only by the claims and their full scope and equivalents.

Claims

1. A LNG storage tank outer coil cold preservation device using BOG cold energy, comprising an LNG storage tank and an outer coil of the storage tank, characterized in that: Also includes: The LNG storage tank comprises an inner tank (4), an outer tank (6) and a cold insulation material (5); The outer coil of the storage tank comprises a second riser (8), a ring pipe (10) and fins (7); The protection mechanism is installed on the outer tank (6) and is used to quickly open and cover the annular tube (10).

2. The LNG storage tank outer coil cold preservation device using BOG cold energy according to claim 1, characterized in that: The second vertical pipe (8) and the third vertical pipe (9) are symmetrically distributed on both sides of the outer tank (6); the annular pipe (10) is a group of pipes distributed at equal intervals along the annular direction of the outer tank (6); each of the annular pipes (10) surrounds the outer tank (6) in one circle and is connected to the second vertical pipe (8) and the third vertical pipe (9) at both ends in the radial direction; the annular pipes (10) are connected by welding through fins (7); the fins (7) are welded at the radial positions of the two ends of the annular pipe (10); and there is a gap between the fins (7) and the surface of the outer tank (6).

3. The LNG storage tank outer coil cold preservation device using BOG cold energy according to claim 2, characterized in that: A first vertical pipe (1) is provided at the top of the inner tank (4); a top pipe (11) connected to the top of the first vertical pipe (1) is provided on the upper surface of the inner tank (4); a safety pressure relief valve (3) is provided on the top pipe (11); a horizontal pipe (2) is fixedly connected to the top of the third vertical pipe (9); an end of the horizontal pipe (2) away from the third vertical pipe (9) is fixedly connected to the top pipe (11); and a shut-off valve (12) is provided at the bottom of the second vertical pipe (8).

4. The LNG storage tank outer coil cold preservation device using BOG cold energy according to claim 1, characterized in that: The protective mechanism comprises an arc-shaped sticking rod (66) sleeved on the top of the outer tank (6), the two ends of the arc-shaped sticking rod (66) are fixedly connected to support plates (61), the bottom ends of a pair of the support plates (61) are fixedly connected to fixed arc-shaped baffles (62), the bottom of the fixed arc-shaped baffle (62) is provided with a plurality of linearly arranged telescopic arc-shaped baffles (63) for telescoping, the middle parts of the telescopic arc-shaped baffles (63) and the fixed arc-shaped baffles (62) are both provided with a pushing spring (65) for pushing the telescopic arc-shaped baffles (63) to block the corresponding ring tube (10), and the two ends of the arc-shaped sticking rod (66) are provided with a binding mechanism for quickly installing the protective mechanism on the top of the outer tank (6).

5. The LNG storage tank outer coil cold preservation device using BOG cold energy according to claim 1, characterized in that: The protection mechanism also includes a pair of limit clamping rods (64) fixedly connected to the two ends of the telescopic arc baffle (63) for clamping the corresponding upper telescopic arc baffle (63) and the fixed arc baffle (62), and a clamping rod mechanism for clamping the telescopic arc baffle (63) to be retracted downward is provided at the bottom of one of the telescopic arc baffles (63).

6. The LNG storage tank outer coil cold preservation device using BOG cold energy according to claim 5, characterized in that: The clamping rod mechanism comprises a rotating seat (17) fixedly connected to one of the telescopic arc baffles (63), a sleeve rod (18) being rotatably connected to the rotating seat (17), a telescopic insertion rod (19) being movably sleeved at the bottom end of the sleeve rod (18), a hook groove (20) for clamping the fixed arc baffle (62) being provided at the bottom end of the telescopic insertion rod (19), and a return spring (22) for pulling the telescopic insertion rod (19) back into the sleeve rod (18) being provided inside the sleeve rod (18).

7. The LNG storage tank outer coil cold preservation device using BOG cold energy according to claim 6, characterized in that: The bottom end of the telescopic rod (19) is fixedly connected to a handle (21).

8. The LNG storage tank outer coil cold preservation device using BOG cold energy according to claim 4, characterized in that: The binding mechanism comprises a first connecting belt (13) and a second connecting belt (14) connected to both ends of an arc-shaped sticking rod (66); the first connecting belt (13) and the second connecting belt (14) are provided with protrusions at their respective opposite ends; the protrusions on the first connecting belt (13) are inlaid with nuts (15); and the protrusions on the second connecting belt (14) are rotatably connected to screws (16) which are spirally connected to the nuts (15).

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