Vacuum negative pressure device for LNG (Liquefied Natural Gas) tank body

Abstract

The invention relates to the technical field of LNG tanks, in particular to a vacuum negative pressure device for an LNG tank. The LNG tank body vacuum negative pressure device solves the technical problem that an LNG tank body in the prior art is prone to deformation. An LNG tank vacuum negative pressure device comprises a base and a tank fixed to the base. The first buffer cavity and the second buffer cavity are sequentially arranged outside the tank body, the vacuum degree of the tank body is larger than that of the first buffer cavity, the vacuum degree of the first buffer cavity is larger than that of the second buffer cavity, and the pressure difference between the air pressure in the tank body and the air pressure of the atmosphere is sequentially divided through the first buffer cavity and the second buffer cavity; therefore, the tank body and the outer tank bear small gas pressure, and the tank body is not prone to deformation. The pumping tank and the outer tank are arranged, the inner tank and the outer tank are both used for protecting the tank body, the tank body cannot be directly collided in the long-term use process or the transportation process, then the tank body is not prone to damage, and the service life of the tank body is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of LNG tanks, and in particular to a vacuum negative pressure device for an LNG tank. Background Art

[0002] LNG storage equipment often uses storage tanks, which are generally coated with silver paint on the outer surface to reflect light, heat, etc., so that the heat absorption inside the storage tank becomes slow.

[0003] Since natural gas is flammable and explosive, the storage tank needs to have a high explosion-proof performance and shield all forms of heat transfer as much as possible to prevent the temperature inside the storage tank from rising. In the prior art, LNG tank bodies usually use reinforcing ribs to increase the strength of the tank body to optimize the explosion-proof performance of the tank body. However, although the LNG tank body in the prior art is provided with reinforcing ribs to improve the strength, the pressure difference between the internal and external air pressure of the LNG tank body is large, which makes the tank body easy to deform or damage.

[0004] Therefore, the LNG tank body in the prior art has the technical problem of being easily deformed. Summary of the invention

[0005] The invention provides a LNG tank vacuum negative pressure device, which solves the technical problem of easy deformation of the LNG tank in the prior art.

[0006] Some implementation plans adopted to solve the above technical problems include: An LNG tank vacuum negative pressure device comprises a base and a tank body fixed to the base; An inner tank and an outer tank are arranged outside the tank body to protect the tank body, the inner tank is located between the outer tank and the tank body, a first buffer cavity is formed between the inner tank and the tank body, the first buffer cavity is sealed, and a second buffer cavity is formed between the outer tank and the inner tank, the second buffer cavity is sealed; The LNG tank vacuum negative pressure device also includes a negative pressure assembly, which includes a first vacuum generator for evacuating the tank, a second vacuum generator for generating negative pressure in the first buffer chamber, and a third vacuum generator for generating negative pressure in the second buffer chamber; The vacuum degree in the tank body is greater than the vacuum degree in the first buffer chamber, and the vacuum degree in the first buffer chamber is greater than the vacuum degree in the second buffer chamber; The negative pressure component is vacuumed by the following steps: Determine the required vacuum level for the tank, Determining the vacuum degree of the first buffer chamber according to the vacuum degree required by the tank body, wherein the vacuum degree of the first buffer chamber is 1 / 2 of the vacuum degree required by the tank body; Determining the vacuum degree of the second buffer cavity according to the vacuum degree of the first buffer cavity, wherein the vacuum degree of the second buffer cavity is 1 / 2 of the vacuum degree of the first buffer cavity; The first vacuum generator, the second vacuum generator and the third vacuum generator are used to evacuate the tank body, the first buffer cavity and the second buffer cavity at the same time, and the first vacuum generator, the second vacuum generator and the third vacuum generator make the air pressure drop speed of the tank body, the first buffer cavity and the second buffer cavity equal.

[0007] Preferably, the tank body is provided with reinforcing ribs for improving the strength of the tank body, the reinforcing ribs and the tank body are an integral structure, and the side of the reinforcing ribs away from the tank body is in contact with the inner wall of the inner tank.

[0008] Preferably, the reinforcing ribs include longitudinal ribs arranged along the axial direction of the tank body and annular ribs arranged along the circumferential direction of the tank body, and the annular ribs are provided with first through holes, which are arranged along the axial direction of the annular ribs.

[0009] Preferably, the cross-sectional shape of the longitudinal ribs is polygonal, and the longitudinal ribs are arranged on the tank body through the annular ribs.

[0010] Preferably, a support frame is provided in the second buffer cavity, the inner side of the support frame contacts the outer wall of the inner tank, and the outer side of the support frame contacts the inner wall of the outer tank.

[0011] Preferably, the support frame includes annular ribs arranged around the inner tank and strip ribs arranged along the length direction of the inner tank, and the annular ribs and the strip ribs are an integrated structure.

[0012] Preferably, the cross-sectional shape of the strip rib is polygonal, and the strip rib does not contact the outer tank or the inner tank.

[0013] Preferably, the annular rib is provided with a second through hole, and the second through hole passes through the annular rib.

[0014] Preferably, the outer wall of the outer tank is provided with protective ribs, the protective ribs are arranged in the outer tank in a grid shape, and the protective ribs and the outer tank are an integrated structure.

[0015] Preferably, the tank body is provided with a first vacuum tube, the first vacuum tube is communicated with the tank body, the first vacuum generator vacuums the tank body through the first vacuum tube, the inner tank is provided with a second vacuum tube, the second vacuum tube is communicated with the first buffer chamber, the second vacuum generator vacuums the first buffer chamber through the second vacuum tube, the outer tank is provided with a third vacuum tube, the third vacuum tube is communicated with the second buffer chamber, and the third vacuum generator vacuums the second buffer chamber through the third vacuum tube.

[0016] Compared with the prior art, the present invention has the following advantages: By sequentially arranging the first buffer chamber and the second buffer chamber outside the tank body, the vacuum degree of the tank body is greater than that of the first buffer chamber, and the vacuum degree of the first buffer chamber is greater than that of the second buffer chamber. The pressure difference between the air pressure in the tank body and the atmospheric pressure is sequentially divided by the first buffer chamber and the second buffer chamber, so that the tank body and the outer tank are subjected to smaller gas pressure, thereby making the tank body less likely to deform.

[0017] By setting up a suction tank and an outer tank, both the inner tank and the outer tank are used to protect the tank body. During long-term use or transportation, the tank body will not be directly collided, making the tank body less likely to be damaged, extending the service life of the tank body and improving the safety of the tank body.

[0018] By making the air pressure drop rates of the tank body, the first buffer cavity, and the second buffer cavity equal, the forces acting on the tank body, the inner tank, and the outer tank change evenly, so that the tank body, the inner tank, and the outer tank are not easily deformed or damaged during the vacuuming process, thereby improving the stability of the vacuuming process. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] For the purpose of explanation, several embodiments of the present invention technology are described in the following drawings. The following drawings are incorporated into this text and constitute a part of the specific embodiment. In some cases, well-known structures and components are shown in block diagram form to avoid obscuring the concept of the present invention subject technology.

[0020] Figure 1 It is a schematic diagram of the internal structure of the present invention.

[0021] Figure 2 It is a schematic diagram of the present invention.

[0022] Figure 3 A schematic diagram of the base.

[0023] Figure 4 A schematic diagram of the outer tank.

[0024] Figure 5 A schematic diagram of the tank.

[0025] Figure 6 Schematic diagram of the inner tank.

[0026] Figure 7 A schematic diagram of the support frame.

[0027] Figure 8 Process flow chart for evacuating negative pressure components.

[0028] As shown in the figure: 1. Base.

[0029] 2. tank body, 21. reinforcing ribs, 211. longitudinal ribs, 212. annular ribs, 2121. first through hole, 23. first vacuum tube.

[0030] 3. Inner tank, 31. Second vacuum tube.

[0031] 4. outer tank, 41. protective ribs, 42. third vacuum tube.

[0032] 5. The first buffer chamber.

[0033] 6. The second buffer chamber.

[0034] 7. Support frame, 71. Ring rib, 711. Second through hole, 72. Strip rib. DETAILED DESCRIPTION

[0035] The specific embodiments shown below are intended to be descriptions of various configurations of the subject technology of the present invention, and are not intended to represent the only configuration that the subject technology of the present invention can be put into practice. The specific embodiments include specific details intended to provide a thorough understanding of the subject technology of the present invention. However, it will be clear and obvious to those skilled in the art that the subject technology of the present invention is not limited to the specific details shown herein, and can be put into practice without these specific details.

[0036] It can be understood that, in this document, relational terms such as “first” and “second” are intended to distinguish one entity or operation from another entity or operation, and are not intended to express or imply any actual relationship or order between these entities or operations.

[0037] The terms "comprises," "comprising," or any other variation thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0038] Reference Figures 1 to 8 As shown, a LNG tank vacuum negative pressure device comprises a base 1 and a tank body 2 fixed to the base 1; The tank body 2 is provided with an inner tank 3 and an outer tank 4 for protecting the tank body 2, the inner tank 3 is located between the outer tank 4 and the tank body 2, a first buffer cavity 5 is formed between the inner tank 3 and the tank body 2, the first buffer cavity 5 is sealed, and a second buffer cavity 6 is formed between the outer tank 4 and the inner tank 3, the second buffer cavity 6 is sealed; The LNG tank vacuum negative pressure device also includes a negative pressure assembly, which includes a first vacuum generator for evacuating the tank body 2, a second vacuum generator for generating negative pressure in the first buffer chamber 5, and a third vacuum generator for generating negative pressure in the second buffer chamber 6; The vacuum degree in the tank body 2 is greater than the vacuum degree in the first buffer chamber 5, and the vacuum degree in the first buffer chamber 5 is greater than the vacuum degree in the second buffer chamber 6; The negative pressure component is vacuumed by the following steps: Determine the required vacuum level for tank 2, The vacuum degree of the first buffer chamber 5 is determined according to the vacuum degree required by the tank body 2, and the vacuum degree of the first buffer chamber 5 is 1 / 2 of the vacuum degree required by the tank body 2; The vacuum degree of the second buffer chamber 6 is determined according to the vacuum degree of the first buffer chamber 5, and the vacuum degree of the second buffer chamber 6 is 1 / 2 of the vacuum degree of the first buffer chamber 5; The first vacuum generator, the second vacuum generator and the third vacuum generator are used to evacuate the tank body 2, the first buffer chamber 5 and the second buffer chamber 6 at the same time, and the first vacuum generator, the second vacuum generator and the third vacuum generator make the air pressure drop speed of the tank body 2, the first buffer chamber 5 and the second buffer chamber equal.

[0039] In some embodiments, the pressure difference between the first buffer chamber 5 and the second buffer chamber 6, and the pressure difference between the tank body 2 and the first buffer chamber 5 are not limited and can be reasonably determined as needed.

[0040] In some embodiments, the first vacuum generator is a first vacuum pump, the second vacuum generator is a second vacuum pump, and the third vacuum generator is a third vacuum pump.

[0041] Reference Figures 1 to 7 As shown, in some embodiments, the outer tank 4 can be fixed to the base 1 in any manner, for example, the outer tank 4 can be directly welded to the base 1, or the outer tank 4 can be fixed to the base 1 by screws.

[0042] In some embodiments, the tank body 2 is provided with a reinforcing rib 21 for improving the strength of the tank body 2 , the reinforcing rib 21 and the tank body 2 are an integral structure, and the side of the reinforcing rib 21 away from the tank body 2 contacts the inner wall of the inner tank 3 .

[0043] The provision of the reinforcing ribs 21 makes the tank body 2 have higher strength, and the tank body 2 is not easily damaged or deformed.

[0044] In some embodiments, the reinforcing ribs 21 include longitudinal ribs 211 arranged along the axial direction of the tank body 2 and annular ribs 212 arranged along the circumferential direction of the tank body 2 , and the annular ribs 212 are provided with first through holes 2121 , which are arranged along the axial direction of the annular ribs 212 .

[0045] The longitudinal ribs 211 and the annular ribs 212 further improve the strength of the tank body 2. The first through holes 2121 are used to interconnect the grid-like cavities formed between the longitudinal ribs 211 and the transverse ribs, so that the first buffer chamber 5 can be easily operated when it is necessary to evacuate the first buffer chamber 5.

[0046] In some embodiments, the cross-sectional shape of the longitudinal rib 211 is polygonal, and the longitudinal rib 211 is disposed on the tank body 2 through the annular rib 212 .

[0047] The cross-sectional shape of the longitudinal rib 211 may be a regular hexagon.

[0048] In some embodiments, a support frame 7 is disposed in the second buffer cavity 6 , the inner side of the support frame 7 contacts the outer wall of the inner tank 3 , and the outer side of the support frame 7 contacts the inner wall of the outer tank 4 .

[0049] The support frame 7 has no fixed relationship with the inner tank 3 and the outer tank 4, and the support ribs independently bear the pressure applied by the outer tank 4 or the inner tank 3. This makes the negative pressure vacuum device of the LNG tank body not easy to be damaged or deformed.

[0050] In some embodiments, the support frame 7 includes an annular rib 212 disposed around the inner tank 3 and a strip rib 72 disposed along the length direction of the inner tank 3 , and the annular rib 212 and the strip rib 72 are an integrated structure.

[0051] In some embodiments, the cross-sectional shape of the strip rib 72 is polygonal, and the strip rib 72 does not contact the outer tank 4 or the inner tank 3 .

[0052] The cross-sectional shape of the strip rib 72 may be a regular hexagon.

[0053] In some embodiments, the annular rib 212 is provided with a second through hole 711, and the second through hole 711 passes through the annular rib 212. The second through hole 711 is provided to connect the space enclosed by the annular rib 212 and the strip rib 72, so that the second buffer chamber 6 is easy to operate when evacuating the vacuum.

[0054] In some embodiments, the outer wall of the outer tank 4 is provided with protective ribs 41 , and the protective ribs 41 are arranged in a grid shape on the outer tank 4 , and the protective ribs 41 and the outer tank 4 are an integrated structure.

[0055] In some embodiments, the tank body 2 is provided with a first vacuum tube 23, the first vacuum tube 23 is communicated with the tank body 2, the first vacuum generator vacuums the tank body 2 through the first vacuum tube 23, the inner tank 3 is provided with a second vacuum tube 31, the second vacuum tube 31 is communicated with the first buffer chamber 5, the second vacuum generator vacuums the first buffer chamber 5 through the second vacuum tube 31, the outer tank 4 is provided with a third vacuum tube 42, the third vacuum tube 42 is communicated with the second buffer chamber 6, and the third vacuum generator vacuums the second buffer chamber 6 through the third vacuum tube 42.

[0056] In some embodiments, the first vacuum generator, the second vacuum generator and the third vacuum generator can all be controlled by PLC, and the first vacuum generator can detect the vacuum degree in the tank body 2, the second vacuum generator can detect the vacuum degree in the first buffer chamber 5, and the third vacuum generator can detect the vacuum degree in the second buffer chamber 6.

[0057] For example, the first vacuum generator, the second vacuum generator and the third vacuum generator may each include an air pressure sensor, and the PLC communicates with the air pressure sensor and controls the first vacuum generator, the second vacuum generator and the third vacuum generator to operate according to parameters detected by the air pressure sensor.

[0058] The above describes the subject technical solution and corresponding details of the present invention. It can be understood that the above description is only some implementation plans of the subject technical solution of the present invention, and some details may be omitted during the specific implementation.

[0059] In addition, in some embodiments of the above invention, multiple embodiments may be implemented in combination, and various combinations are not listed one by one due to space limitations. Those skilled in the art can freely combine and implement the above embodiments as needed in specific implementation to obtain a better application experience.

[0060] When implementing the subject technical solution of the present invention, those skilled in the art can obtain other detailed configurations or drawings based on the subject technical solution of the present invention and the drawings. Obviously, these details still fall within the scope covered by the subject technical solution of the present invention without departing from the subject technical solution of the present invention.

Claims

1. A LNG tank vacuum negative pressure device, characterized in that: The LNG tank vacuum negative pressure device comprises a base (1), and a tank body (2) fixed to the base (1); an inner tank (3) and an outer tank (4) for protecting the tank body (2) are arranged outside the tank body (2); the inner tank (3) is located between the outer tank (4) and the tank body (2); a first buffer chamber (5) is formed between the inner tank (3) and the tank body (2); the first buffer chamber (5) is sealed; a second buffer chamber (6) is formed between the outer tank (4) and the inner tank (3); the second buffer chamber (6) is sealed; the LNG tank vacuum negative pressure device also comprises a negative pressure assembly, the negative pressure assembly comprises a first vacuum generator for evacuating the tank body (2), a second vacuum generator for generating negative pressure in the first buffer chamber (5), and a third vacuum generator for generating negative pressure in the second buffer chamber (6); the vacuum degree in the tank body (2) is greater than the vacuum degree in the first buffer chamber (5); the vacuum degree in the first buffer chamber (5) is greater than the vacuum degree in the second buffer chamber (6); The vacuum degree of the buffer chamber (6); wherein the negative pressure component is vacuumed by the following steps: determining the vacuum degree required for the tank body (2), determining the vacuum degree of the first buffer chamber (5) according to the vacuum degree required for the tank body (2), the vacuum degree of the first buffer chamber (5) being 1 / 2 of the vacuum degree required for the tank body (2); determining the vacuum degree of the second buffer chamber (6) according to the vacuum degree of the first buffer chamber (5), the vacuum degree of the second buffer chamber (6) being 1 / 2 of the vacuum degree of the first buffer chamber (5); and utilizing the first vacuum generator, the second vacuum generator and the third vacuum generator to simultaneously vacuum the tank body (2), the first buffer chamber (5) and the second buffer chamber (6), and the first vacuum generator, the second vacuum generator and the third vacuum generator to make the air pressure drop speeds of the tank body (2), the first buffer chamber (5) and the second buffer chamber equal.

2. The LNG tank vacuum negative pressure device according to claim 1 is characterized in that: The tank body (2) is provided with a reinforcing rib (21) for improving the strength of the tank body (2); the reinforcing rib (21) and the tank body (2) are an integral structure; a side of the reinforcing rib (21) away from the tank body (2) contacts the inner wall of the inner tank (3).

3. The LNG tank vacuum negative pressure device according to claim 2 is characterized in that: The reinforcing ribs (21) comprise longitudinal ribs (211) arranged along the axial direction of the tank body (2) and annular ribs (212) arranged along the circumferential direction of the tank body (2); the annular ribs (212) are provided with first through holes (2121); and the first through holes (2121) are arranged along the axial direction of the annular ribs (212).

4. The LNG tank vacuum negative pressure device according to claim 3 is characterized in that: The cross-sectional shape of the longitudinal rib (211) is polygonal, and the longitudinal rib (211) is arranged on the tank body (2) via the annular rib (212).

5. The LNG tank vacuum negative pressure device according to claim 1, characterized in that: A support frame (7) is arranged in the second buffer cavity (6), the inner side of the support frame (7) contacts the outer wall of the inner tank (3), and the outer side of the support frame (7) contacts the inner wall of the outer tank (4).

6. The LNG tank vacuum negative pressure device according to claim 5, characterized in that: The support frame (7) comprises an annular rib (212) arranged around the inner tank (3) and a strip rib (72) arranged along the length direction of the inner tank (3); the annular rib (212) and the strip rib (72) are an integrated structure.

7. The LNG tank vacuum negative pressure device according to claim 6, characterized in that: The cross-sectional shape of the strip rib (72) is polygonal, and the strip rib (72) does not contact the outer tank (4) or the inner tank (3).

8. The LNG tank vacuum negative pressure device according to claim 7, characterized in that: The annular rib (212) is provided with a second through hole (711), and the second through hole (711) passes through the annular rib (212).

9. The LNG tank vacuum negative pressure device according to claim 1, characterized in that: The outer wall of the outer tank (4) is provided with protective ribs (41), the protective ribs (41) are arranged in a grid pattern on the outer tank (4), and the protective ribs (41) and the outer tank (4) are an integrated structure.

10. The LNG tank vacuum negative pressure device according to claim 1, characterized in that: The tank body (2) is provided with a first vacuum pumping pipe (23), the first vacuum pumping pipe (23) being in communication with the tank body (2), the first vacuum generator evacuating the tank body (2) through the first vacuum pumping pipe (23), the inner tank (3) is provided with a second vacuum pumping pipe (31), the second vacuum pumping pipe (31) being in communication with the first buffer chamber (5), the second vacuum generator evacuating the first buffer chamber (5) through the second vacuum pumping pipe (31), and the outer tank (4) is provided with a third vacuum pumping pipe (42), the third vacuum pumping pipe (42) being in communication with the second buffer chamber (6), the third vacuum generator evacuating the second buffer chamber (6) through the third vacuum pumping pipe (42).

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