A top liquid inlet pipe structure for a cryogenic liquid tank

Abstract

The present invention discloses a top liquid inlet pipe structure of a cryogenic liquid tank box. The liquid tank box is provided with an outer tank body, an inner tank body, and a liquid inlet pipe. The liquid inlet end is located at the upper part of the inner tank body and above the highest liquid level that the inner tank body is allowed to contain. The liquid inlet end is provided with an impact dispersion structure that meets the requirement of large flow rate liquid inlet and disperses the liquid flowing through in the upper space of the inner tank body. The impact dispersion structure increases the contact surface of the inflowing liquid with the gas phase at the top of the inner tank body and enhances the mass transfer effect through the collision between the fluid and the collision surface of a specific shape or the mutual collision between the fluids, so that the gas in the gas phase space is reliquefied. The guiding semi-enclosed plate and the collision surface arranged at the outlet end can realize multiple collision deflections for the inflowing liquid flow, so that the liquid dispersion increases the contact area with the gas phase in the tank, so that the gas in the gas phase space can be cooled, so as to realize the gas in the gas phase space to be reliquefied, reduce the internal pressure of the tank body, and thus reduce the emission of gas.

Description

Technical Field

[0001] The invention relates to the technical field of cryogenic transport tank containers, and in particular to a top liquid inlet pipe structure of a cryogenic liquid tank container. Background Art

[0002] Cryogenic tanks are containers specially designed for transporting and storing cryogenic liquids. These liquids usually include liquefied natural gas (LNG), liquid oxygen, liquid nitrogen, liquid argon, etc. The design of cryogenic tanks requires special consideration of material selection and the application of insulation technology to ensure that the extremely low temperature of the internal materials can be maintained during long-term transportation to prevent evaporation losses.

[0003] When using high vacuum multi-layer insulated cryogenic liquid tank trucks for transportation, the tank needs to be filled with liquid before transportation. A top liquid inlet pipe is provided on the upper part of the container inside the tank. Patent application number: 201910717553.1 provides a marine storage tank, which includes a tank body and an outer liquid inlet pipe and an inner liquid inlet pipe arranged on the tank body. The inner liquid inlet pipe is located inside the inner tank, the top of the inner liquid inlet pipe is connected to the outer liquid inlet pipe, and the inner liquid inlet pipe extends along the top of the inner tank to the bottom of the inner tank. The inner liquid inlet pipe is bent along the contour of the inner wall of the inner tank, and the degree of bending of the inner liquid inlet pipe is adapted to the contour of the inner wall of the inner tank; the central angle corresponding to the inner liquid inlet pipe is greater than 180 degrees. It adopts the method of extending the liquid inlet pipe into the bottom of the liquid of the cryogenic tank container for liquid filling operation. Although it can avoid disturbing the upper liquid, this method also has some obvious disadvantages and potential risks; specifically: 1. It is easy to damage the bottom of the tank: especially for cryogenic tank containers for special transportation operations, the impact force during liquid filling may cause physical damage to the bottom of the tank if the bottom is impacted at the same position for a long time. 2. Local supercooling caused by the flushing of cryogenic liquid: When the cryogenic liquid is sprayed directly onto the bottom of the tank, it may cause a sudden drop in the local temperature of the tank bottom, which will not only affect the thermal stress distribution of the tank material, but may also increase the cold brittleness of the material, thereby causing cracks and other problems. 3. Increased evaporation rate: Although direct liquid inlet from the bottom reduces the disturbance of the liquid surface, this method of liquid inlet may cause the risk of instantaneous increase in the pressure in the tank, thereby increasing the evaporation rate, especially when handling volatile cryogenic liquids.

[0004] In view of the above, it is necessary to propose a top liquid inlet pipe structure of a cryogenic liquid tank to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects in the prior art and provide a top liquid inlet pipe structure for a cryogenic liquid tank.

[0006] To achieve the above-mentioned purpose, the technical scheme of the present invention is as follows: a top liquid inlet pipe structure of a cryogenic liquid tank box, the liquid tank box is provided with an outer tank body and an inner tank body, a liquid inlet pipe is provided from the outside of the liquid tank box through the outer tank body and the inner tank body in sequence, the end of the liquid inlet pipe located at the inner tank body is the liquid inlet end, the liquid inlet end is located at the upper part of the inner tank body and is located above the highest liquid level allowed to be contained in the inner tank body; the liquid inlet end is provided with an impact dispersion structure that meets the large flow rate of liquid inlet and disperses the liquid flowing through in the upper space of the inner tank body; the impact dispersion structure increases the gas phase contact surface of the inflowing liquid with the top of the inner tank body and enhances the mass transfer effect through the collision surface of the fluid with a specific shape or the mutual collision between the fluids, so as to reliquefy the gas in the gas phase space.

[0007] Furthermore, the impact dispersion structure includes a guide semi-closed plate, and the liquid inlet end is processed to form a first bevel cut and a second bevel cut, and the first bevel cut and the second bevel cut are respectively located on the upper and lower sides of the end of the liquid inlet pipe, the first bevel cut is on the lower side and forms an angle a with the horizontal plane, and the second bevel cut is on the upper side and forms an angle b with the horizontal plane; the guide semi-closed plate is arranged on the first bevel cut, so that the second bevel cut is an opening, so that the liquid inlet end forms a semi-closed opening, and the liquid flow is deflected and turned to be ejected through the second bevel cut after hitting the guide semi-closed plate, and the second bevel cut faces the inner wall of the top of the inner tank body. The liquid flow is deflected downward again after the second impact on the top wall of the inner tank body and is scattered in the upper space of the tank body.

[0008] Furthermore, the angle range of the angle a and the angle b is 30° to 60°; a flow gap is left between the lower end of the guide semi-enclosed plate and the lower end of the first oblique cut; the upper half of the circular surface of the straight tube portion close to the liquid inlet end is provided with injection holes at intervals along the circumferential direction; and a U-shaped tube portion bent downward is provided on the horizontally arranged straight tube portion in the middle of the liquid inlet pipe.

[0009] Furthermore, the liquid inlet pipe is provided with a straight pipe portion along the axial direction of the tank body, and rib pipes are respectively branched on both sides of the straight pipe portion. The ends of the rib pipes on both sides are liquid inlet ends, and the ends of the rib pipes on both sides are arranged opposite to each other, so that the liquid flows sprayed from the ends of the rib pipes on both sides collide with each other to form an impact dispersion structure.

[0010] Furthermore, the height position of the liquid inlet end is at a middle position between the highest liquid level and the inner top surface of the inner tank body.

[0011] Furthermore, the impact dispersion structure includes an air intake chamber, one end of which is connected to a liquid inlet pipe and the other end is provided with a throat. The liquid inlet pipe is connected to a nozzle that passes through the air intake chamber, the end of the nozzle points to the throat, and the other end of the throat is provided with a conical diffuser with a gradually expanding diameter; the circumferential side wall of the air intake chamber is provided with an air inlet.

[0012] Furthermore, the impact surface includes an arc-shaped dispersion base arranged on the top wall of the inner tank body at the liquid injection impact position, and the arc-shaped dispersion base is provided with an arc-shaped concave surface on the side facing the liquid inlet end.

[0013] Furthermore, a conical tip portion protruding toward the liquid outlet end is provided in the middle of the arc-shaped concave surface.

[0014] Furthermore, the liquid inlet pipe is provided with a float valve structure on the side of the U-shaped tube portion away from the liquid inlet end to prevent the liquid flow from moving in the opposite direction. The float valve structure includes a connecting tube, and both ends of the connecting tube are provided with threaded connecting ends for connecting the liquid inlet pipes at the front and rear ends. A valve core structure is provided inside the connecting tube, and the valve core structure includes a sealing member and a floating core portion that can move freely along the axial direction. The floating core portion moves toward the sealing member under the push of the liquid retained in the U-shaped tube portion and cooperates with the sealing member to close the liquid inlet pipe.

[0015] Furthermore, a chamber with an enlarged diameter is provided in the middle of the connecting tube, and the floating core moves in the enlarged chamber. The floating core includes an axial guide rod and an inclined conical surface. The axial guide rod is arranged along the axis to pass through the inclined conical surface, and the inclined conical surface cooperates with the sealing member. The floating valve structure also includes a guide frame, and the guide frame is provided with a guide hole for the axial guide rod to pass through at least at the center of the connecting tube.

[0016] The advantages and beneficial effects of the present invention are as follows: compared with the traditional liquid inlet pipe, the top liquid inlet pipe structure of the cryogenic liquid tank box of the present invention can realize multiple impact deflections of the inflowing liquid flow by the guiding semi-enclosed plate and the impact surface arranged at the outlet end, so that the liquid is dispersed to increase the contact area with the gas phase in the tank, so that the gas in the gas phase space can be cooled, thereby realizing the re-liquefaction of the gas in the gas phase space, reducing the internal pressure of the tank body, and thus reducing the emission of gas.

[0017] The opposing structure design of fin tubes can realize the collision of liquids, avoid the liquids hitting the surface of the inner tank, and thus avoid the influence on the width of the inner tank. Multiple groups of fin tubes can be arranged in an array, and arranged in the tank body so that when feeding, the gas phase space inside the tank body can be connected with the incoming liquid phase at all places, further increasing the heat exchange area with the gas phase.

[0018] The float valve structure is set to effectively prevent the reverse flow of liquid from affecting the feed pipeline, feed pump and other facilities when the pressure in the tank increases abnormally. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of a top liquid inlet pipe structure of a cryogenic liquid tank container of the present invention; Figure 2 It is a detailed diagram of the top liquid inlet pipe in the present invention; Figure 3 The present invention Figure 2A partial enlarged view of the middle circle; Figure 4 The present invention Figure 3 Front view from the middle A direction; Figure 5 The present invention Figure 4 Structural diagram of the middle BB section; Figure 6 It is one of the structural schematic diagrams of the arc-shaped dispersion base in the present invention; Figure 7 This is the second structural schematic diagram of the arc-shaped dispersion base in the present invention; Figure 8 is a front view of the ribbed tubular top liquid inlet pipe structure of the present invention; Fig. 9 is a side view of the ribbed tubular top liquid inlet pipe structure of the present invention; Fig.10 is a schematic structural diagram of an impact dispersion structure in a fourth embodiment of the present invention; Fig.11 is a schematic structural diagram of a fifth embodiment of the present invention; Fig.12 is a schematic diagram of the float valve structure of the present invention; Fig.13 The present invention Fig.12 Structural diagram of the AA section; In the figure: 1, inner tank; 2, liquid inlet pipe; 3, liquid inlet end; 4, impact dispersion structure; 5, impact surface; 6, guide semi-enclosed plate; 7, first oblique cut; 8, second oblique cut; 9, angle a; 10, angle b; 11, flow gap; 12, injection hole; 13, U-shaped pipe; 14, straight pipe; 15, rib pipe; 16, suction chamber; 17, throat; 18, nozzle; 19, diffuser; 2 0. Air inlet; 21. Arc-shaped dispersion base; 22. Arc-shaped concave surface; 23. Conical tip; 24. Float valve structure; 25. Connecting pipe; 26. Threaded connection end; 27. Seal; 28. Floating core; 29. ​​Enlarged chamber; 30. Axial guide rod; 31. Oblique cone surface; 32. Guide frame; 33. Guide hole; 34. Pressure measuring tube; 35. Pressure gauge gas phase tube; 36. Outer ring; 37. Support rod. DETAILED DESCRIPTION

[0020] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0021] Embodiment 1: A top liquid inlet pipe structure of a cryogenic liquid tank container, wherein the liquid tank container is provided with an outer tank body and an inner tank body 1, such as Figure 1As shown, a liquid inlet pipe 2 is provided from the outside of the liquid tank box, passing through the outer tank body and the inner tank body 1 in sequence. The end of the liquid inlet pipe 2 located at the inner tank body 1 is a liquid inlet end 3. The liquid inlet end 3 is located at the upper part of the inner tank body 1 and is located above the highest liquid level allowed to be contained in the inner tank body 1; the liquid inlet end 3 is provided with an impact dispersion structure 4 that meets the large flow rate of liquid inlet and disperses the liquid flowing through in the upper space of the inner tank body 1; the impact dispersion structure 4 increases the gas phase contact surface of the inflowing liquid with the top of the inner tank body 1 and enhances the mass transfer effect through the collision between the fluid and the collision surface 5 of a specific shape or the mutual collision between the fluids, so that the gas in the gas phase space is reliquefied.

[0022] Specifically, Figure 3 As shown, the impact dispersion structure 4 includes a guide semi-enclosed plate 6, and the liquid inlet end 3 is processed to form a first oblique cut 7 and a second oblique cut 8. The first oblique cut 7 and the second oblique cut 8 are respectively located at the upper and lower sides of the end of the liquid inlet pipe 2. The first oblique cut 7 is on the lower side and forms an angle a9 with the horizontal plane, and the second oblique cut 8 is on the upper side and forms an angle b10 with the horizontal plane. The guide semi-enclosed plate 6 is arranged on the first oblique cut 7, so that the second oblique cut 8 is an opening, so that the liquid inlet end 3 forms a semi-enclosed opening, and the liquid flow is deflected and turned after hitting the guide semi-enclosed plate 6 to be ejected through the second oblique cut 8, as shown in FIG. Figure 2 , 3 As shown, when the fluid enters the inner tank body 1 through the liquid inlet pipe 2 and reaches the liquid inlet end 3, it first collides with the guide semi-enclosed plate 6 on the first oblique cut 7. The guide semi-enclosed plate 6 can perform a first deflection and guide on the fluid, and form a release and pressure reduction at the outlet end. After the first collision, a certain dispersion and diffusion effect can be formed; the second oblique cut 8 is toward the inner wall of the top of the inner tank body 1. In order to meet the larger flow rate of fluid entering, the liquid inlet pipe 2 is not pressed at the liquid inlet end 3. The second oblique cut 8 on the upper side expands the opening area for the fluid to flow out, so that more fluid can enter the inner tank body 1. Figure 1 As shown, the second impact of the liquid flow through the top wall of the inner tank body 1 is deflected downward again and scattered in the upper space of the tank body. In this embodiment, the top wall of the inner tank body 1 forms an impact surface 5 for collision. At this time, the fluid is deflected downward after the impact, thereby contacting the gas phase in the gas phase space inside the tank body, and after two collisions, the fluid entering the inner tank body 1 through the liquid inlet pipe 2 is further impacted and dispersed, further increasing the contact surface with the gas phase, forming a better contact effect with the gas phase.

[0023] A top liquid inlet pipe 2 is arranged at the upper part of the container in the tank body. During the filling process of the liquid, since there is about 5-10% of gas phase space at the top, the gas in the gas phase space can be effectively cooled by filling the liquid into the top, thereby realizing the reliquefaction of the gas in the gas phase space, reducing the internal pressure of the container in the tank body, and reducing gas emissions; the top liquid inlet pipe 2 ends are semi-blocked sealing plate opening design, and the liquid entering through the top liquid inlet pipe 2 is sprayed into the inner container in a timely manner; Figure 1 As shown, in actual use, the inner tank body 1 is also provided with a pressure gauge 34 for connecting a pressure gauge, and a pressure gauge gas phase pipe 35 is provided in the inner tank body 1, so as to facilitate observation of the internal pressure of the inner container during transportation. In the design, the port of the liquid inlet pipe 2 faces the end of the pressure gauge gas phase pipe 35, so that liquid is easily splashed into the pressure gauge 34 when the liquid is inlet. The traditional sealing plate directly blocks it, which will cause inaccurate readings of the pressure gauge set at the front head, thereby affecting the safety of the tank tank truck. In view of the problems, this embodiment optimizes the design of the liquid outlet at the top liquid inlet end by changing the liquid flow direction, adopts an oblique structure, solves the influence of the liquid in the pressure gauge gas phase pipe 35 on the pressure gauge, and after multiple deflections, not only avoids the port of the pressure gauge 34, but also makes the fluid distribution more dispersed in the collision, increasing the gas phase contact area; reduces the internal pressure of the container in the tank body during filling, and reduces gas emissions.

[0024] In some embodiments, the angle a9 and the angle b10 range from 30° to 60°; as a preferred embodiment, Figure 3 As shown in the above figure, the angle a9 and the angle b10 are both designed to be 45°, and a flow gap 11 is left between the lower end of the guide semi-enclosed plate 6 and the lower end of the first oblique cut 7; Figure 4 As shown, specifically, a 3mm gap is left at the bottom of the pipe mouth to prevent impurities in the liquid coming from the top, so that it can flow out from the bottom gap. According to the flow direction arrow of the pipe mouth, it can be seen that after the liquid flows out, the liquid will not directly enter the gas phase pipe 35 of the pressure gauge, which is convenient for protecting the pressure gauge and making the pressure gauge reading more accurate. Figure 2 , 5 As shown, the upper half of the circular surface of the straight tube portion 14 near the liquid inlet end 3 is provided with injection holes 12 at intervals along the circumferential direction. In addition to providing a guiding semi-enclosed plate 6 at the end of the liquid inlet pipe 2, the addition of the upwardly opening injection holes 12 can not only increase the flow rate entering the tank body, but also allow the fluid to be sprayed upward and hit the top wall of the inner tank body 1 to form collision diffusion. In actual use, in order to avoid wear on the surface of the inner tank body 1 caused by fluid impact, a thickened plate can be provided at the fluid collision position.

[0025] Embodiment 2: As an improvement of the thickened plate described in the above embodiment, Figure 6As shown, the impact surface 5 includes an arc-shaped dispersion base 21 arranged on the top wall of the inner tank body 1 at the liquid ejection impact position, and the arc-shaped dispersion base 21 is provided with an arc-shaped concave surface 22 on the side facing the liquid inlet end 3. In this embodiment, the setting range of the arc-shaped concave surface 22 should cover the area formed by the fluid after being ejected from the liquid inlet end 3 when the fluid changes within a certain pressure range, and the middle part of the arc-shaped concave surface 22 is arched upward, and the edge position is relatively low, so that the ejected liquid is covered in the diffusion range along the direction of the tangent line of the edge of the arc-shaped concave surface 22 after being deflected by the arc-shaped concave surface 22, forming a curtain-like diffusion, which increases the gas phase contact area while effectively avoiding the gas phase pipe 35 of the pressure gauge.

[0026] Further, as a preferred embodiment, Figure 7 As shown, the middle part of the arc-shaped concave surface 22 is provided with a conical tip portion 23 which is raised toward the liquid outlet end. The conical tip portion 23 is formed in the middle part of the concave surface so that the injected liquid can first hit the conical tip portion 23 to form a preliminary dispersion. It can be understood that the conical tip portion 23 can be point-shaped or prismatic. When the fluid passes through the first deflection of the semi-enclosed plate 6 guided by the liquid inlet end 3, a jet with a certain fan-shaped expansion angle can be formed. In this way, the prismatic conical tip portion 23 can be used to cover the fan-shaped expansion angle of the jet.

[0027] Preferably, a U-shaped tube portion 13 bent downward is provided on a horizontally arranged straight tube portion 14 in the middle of the liquid inlet pipe 2. In actual use, a certain amount of liquid can be held in the U-shaped tube portion 13, and the sealing effect of the liquid inlet pipe 2 can be enhanced after the feeding is completed.

[0028] Embodiment three: The liquid inlet pipe 2 is provided with a straight pipe portion 14 along the axial direction of the tank body, and rib tubes 15 are respectively branched on both sides of the straight pipe portion 14. In actual use, a pair of rib tubes 15 on both sides constitute a group, and only one group or multiple groups can be provided. Figure 8 , 9 As shown, the ends of the rib tubes 15 on both sides are the liquid inlet ends 3, and the ends of the rib tubes 15 on both sides are arranged opposite to each other, so that the liquid flows sprayed from the ends of the rib tubes 15 on both sides collide with each other to form an impact dispersion structure 4. Figure 8 As shown, a plurality of groups of rib tubes 15 are sequentially arranged at intervals along the straight tube portion 14. Fig. 9 As shown, the ends of the fin tubes 15 on both sides are arranged opposite to each other. When liquid is fed in, the liquid is sprayed out from the liquid inlet end 3 opposite to each other, so that the liquids collide with each other, and then diffuse and increase the contact area with the gas phase.

[0029] Preferably, the height position of the liquid inlet end 3 is in the middle position between the highest liquid level and the inner top surface of the inner tank body 1. Fig. 9As shown, the liquid inlet pipe 2 extends downward into the inner tank body 1 to a certain depth, so that the straight tube portion 14 can be located in the inner tank body 1 and at a certain distance from the top. Therefore, when liquid is introduced, as the liquid level rises, the liquid level can submerge the straight tube portion 14. During the process of the fluid passing through the straight tube portion 14 for feeding, due to the immersion design of the straight tube portion 14, the original low-temperature liquid in the inner tank body 1 can exchange heat with the incoming fluid. It can be understood that the temperature of the liquid flowing in from the outside is slightly increased or a small amount of fluid is vaporized outside the tank body due to the influence of the external temperature. After cooling and heat exchange by the immersed straight tube portion 14, the liquid inlet temperature can be maintained at a relatively low state, and some gas entrained by the incoming fluid can be liquefied in the straight tube portion 14, and no gas-like spray will be formed. It can be understood that in the present embodiment, the straight tube portion 14 does not have to be arranged at a lower position, because in the initial stage of feeding, the space in the inner tank body 1 is relatively large, and the tank pressure caused by the liquid inflow rises slowly; and as the feed increases, the liquid level rises, and the top space in the tank is greatly reduced. At this time, it is necessary to pay attention to controlling the pressure in the tank. Therefore, after the liquid level rises to a certain position, the liquid level is immersed in the straight tube portion 14, which can effectively deal with the problem of rapid increase in tank pressure when liquid is inflow.

[0030] Embodiment 4: The impact dispersion structure 4 includes an air suction chamber 16, one end of which is connected to the liquid inlet pipe 2, and the other end is provided with a throat 17. The liquid inlet pipe 2 is connected with a nozzle 18 passing through the air suction chamber 16, and the end of the nozzle 18 points to the throat 17. The other end of the throat 17 is provided with a conical diffuser 19 with a gradually increasing diameter; the circumferential side wall of the air suction chamber 16 is provided with an air inlet 20. Fig.10 As shown, in this embodiment, the throat 17 and the diffuser 19 are arranged to form a Venturi injection tube structure. When the fluid is sprayed into the throat 17 by the nozzle 18 and then forms a sudden pressure drop through the diffuser 19, a relative negative pressure area is formed in the suction chamber 16. In this way, the gas phase medium in the gas phase space above the liquid surface can be absorbed into the gas phase space through the air inlet 20 arranged around, so that the gas phase and the fluid form a mutual extrusion and collision mixture at the throat 17 and the diffuser 19. In this process, the temperature is transferred, so that the inhaled gas phase is converted into the liquid phase in the process, and then the pressure in the gas phase space inside the tank body is reduced, reducing the emission of gas during the feeding process. It can be understood that this embodiment can be applied to the position of the liquid inlet end 3 in the aforementioned embodiments.

[0031] Embodiment five: like Fig.11 As shown, the liquid inlet pipe 2 is provided with a float valve structure 24 on the side of the U-shaped tube portion 13 away from the liquid inlet end 3 to prevent the liquid flow from moving in the opposite direction. The float valve structure 24 prevents the liquid from flowing back and avoids the reverse flow of the liquid from impacting the front end equipment of the liquid inlet pipe 2.

[0032] The float valve structure 24 includes a connecting tube 25, and the two ends of the connecting tube 25 are provided with threaded connection ends 26 for connecting the liquid inlet pipe 2 at the front and rear ends. A valve core structure is provided inside the connecting tube 25, and the valve core structure includes a sealing member 27 and a floating core 28 that moves freely along the axial direction. The floating core 28 moves toward the sealing member 27 under the push of the liquid retained in the U-shaped tube 13 and seals the liquid inlet pipe 2 with the sealing member 27. Figure 11-13 As shown, when liquid is introduced, the liquid pushes the floating core 28 to move to the left. At this time, the float valve structure 24 is in the open state. If the internal pressure of the tank increases, the floating core 28 is pushed to move only by the reverse flow of gas, and the driving force formed by the gas is relatively small. In this embodiment, the float valve structure 24 is combined with the U-shaped tube portion 13. When the internal pressure increases, the liquid inside the U-shaped tube is squeezed first. When the liquid moves in the liquid inlet pipe 2, the force it exerts on the floating core 28 is relatively large, and the floating core 28 can be firmly pressed against the seal 27, thereby forming a better sealing performance.

[0033] Specifically, a chamber 29 with an enlarged diameter is provided in the middle of the connecting tube 25, and the floating core 28 moves in the enlarged chamber 29. The enlarged chamber 29 can meet the needs of large flow rate feeding, so that it will not reduce the effective feeding cross-sectional area of ​​the liquid inlet pipe 2 during feeding. The floating core 28 includes an axial guide rod 30 and an inclined cone surface 31. The axial guide rod 30 is arranged along the axis through the inclined cone surface 31, and the inclined cone surface 31 cooperates with the seal 27; the float valve structure 24 also includes a guide frame 32, and the guide frame 32 is provided with a guide hole 33 for the axial guide rod 30 to pass through at least at the center of the connecting tube 25. Through the cooperation of the guide rod and the guide frame 32, the movement position of the floating core 28 can be accurate and strictly moved along the axis, so that the inclined cone surface 31 and the seal 27 are in perfect contact and sealing. Fig.13 As shown, the guide frame 32 includes an outer ring 36 and a support rod 37. The outer ring 36 is concentrically arranged with the guide hole 33, and a plurality of support rods 37 are arranged between the two for fixing. In actual use, an internal thread can be formed on the inner wall of the connecting tube 25, and an external thread can be formed on the outer wall of the outer ring 36, so that the guide frame 32 can be installed in the float valve structure 24 in a threaded connection manner, which can achieve the advantages of easy installation and easy adjustment of the axial position, so that the moving stroke of the floating core 28 can be controlled and adjusted.

[0034] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A top liquid inlet pipe structure of a cryogenic liquid tank, wherein the liquid tank is provided with an outer tank body and an inner tank body (1), and a liquid inlet pipe (2) is provided from the outside of the liquid tank through the outer tank body and the inner tank body (1) in sequence, characterized in that: The end of the liquid inlet pipe (2) located in the inner tank body (1) is the liquid inlet end (3), and the liquid inlet end (3) is located in the upper part of the inner tank body (1) and is located above the highest liquid level that the inner tank body (1) is allowed to contain; the liquid inlet end (3) is provided with an impact dispersion structure (4) that satisfies the requirement of large flow rate liquid inlet and disperses the liquid flowing through in the upper space of the inner tank body (1); the impact dispersion structure (4) increases the gas phase contact surface of the inflowing liquid with the top of the inner tank body (1) and enhances the mass transfer effect through the collision between the fluid and the collision surface (5) of a specific shape or between the fluids, thereby reliquefying the gas in the gas phase space.

2. The top liquid inlet pipe structure of a cryogenic liquid tank container according to claim 1, characterized in that: The impact dispersion structure (4) comprises a guide semi-enclosed plate (6), the liquid inlet end (3) is processed to form a first oblique cut (7) and a second oblique cut (8), the first oblique cut (7) and the second oblique cut (8) are respectively located at the upper and lower sides of the end of the liquid inlet pipe (2), the first oblique cut (7) is at the lower side and forms an angle a (9) with the horizontal plane, and the second oblique cut (8) is at the upper side and forms an angle b (10) with the horizontal plane; the guide semi-enclosed plate (6) is arranged on the first oblique cut (7), so that the second oblique cut (8) is an opening, so that the liquid inlet end (3) forms a semi-enclosed opening, after the liquid flow hits the guide semi-enclosed plate (6), it is deflected and turned to spray out through the second oblique cut (8), the second oblique cut (8) faces the inner wall of the top of the inner tank body (1), and the liquid flow is deflected downward again after a second impact on the top wall of the inner tank body (1) and is scattered and distributed in the upper space of the tank body.

3. The top liquid inlet pipe structure of a cryogenic liquid tank container according to claim 2, characterized in that: The angles a (9) and b (10) are in the range of 30° to 60°; a flow gap (11) is left between the lower end of the guide semi-enclosed plate (6) and the lower end of the first oblique cutout (7); injection holes (12) are provided at intervals along the circumferential direction on the upper half of the circular surface of the straight tube portion (14) close to the liquid inlet end (3); and a U-shaped tube portion (13) bent downward is provided on the horizontally arranged straight tube portion (14) in the middle of the liquid inlet pipe (2).

4. The top liquid inlet pipe structure of a cryogenic liquid tank container according to claim 1, characterized in that: The liquid inlet pipe (2) is provided with a straight pipe portion (14) along the axial direction of the tank body, and rib pipes (15) are respectively branched on both sides of the straight pipe portion (14). The ends of the rib pipes (15) on both sides are liquid inlet ends (3). The ends of the rib pipes (15) on both sides are arranged opposite to each other, so that the liquid flows ejected from the ends of the rib pipes (15) on both sides collide with each other to form an impact dispersion structure (4).

5. The top liquid inlet pipe structure of a cryogenic liquid tank container according to claim 4, characterized in that: The height position of the liquid inlet end (3) is at a midpoint between the highest liquid level and the inner top surface of the inner tank body (1).

6. A top liquid inlet pipe structure of a cryogenic liquid tank container according to any one of claims 1, 4 or 5, characterized in that: The impact dispersion structure (4) comprises an air intake chamber (16), one end of the air intake chamber (16) is connected to a liquid inlet pipe (2), and the other end is provided with a throat pipe (17), the liquid inlet pipe (2) is connected to a nozzle (18) passing through the air intake chamber (16), the end of the nozzle (18) points to the throat pipe (17), and the other end of the throat pipe (17) is provided with a conical diffuser (19) with a gradually increasing diameter; the circumferential side wall of the air intake chamber (16) is provided with an air inlet (20).

7. The top liquid inlet pipe structure of a cryogenic liquid tank container according to claim 2, characterized in that: The impact surface (5) comprises an arc-shaped dispersion base (21) arranged on the top wall of the inner tank body (1) at a position where the liquid is ejected and impacted, and the arc-shaped dispersion base (21) is provided with an arc-shaped concave surface (22) on the side facing the liquid inlet end (3).

8. The top liquid inlet pipe structure of a cryogenic liquid tank container according to claim 7, characterized in that: A conical tip portion (23) that bulges toward the liquid outlet end is provided in the middle of the arc-shaped concave surface (22).

9. The top liquid inlet pipe structure of a cryogenic liquid tank container according to claim 3, characterized in that: The liquid inlet pipe (2) is provided with a float valve structure (24) on the side of the U-shaped pipe portion (13) away from the liquid inlet end (3) to prevent the liquid flow from moving in the reverse direction. The float valve structure (24) comprises a connecting pipe (25). Both ends of the connecting pipe (25) are provided with threaded connecting ends (26) for connecting the liquid inlet pipe (2) at the front and rear ends. A valve core structure is provided inside the connecting pipe (25). The valve core structure comprises a sealing member (27) and a floating core (28) that is freely movable in the axial direction. The floating core (28) moves toward the sealing member (27) under the push of the liquid retained in the U-shaped pipe portion (13) and seals the liquid inlet pipe (2) with the sealing member (27).

10. The top liquid inlet pipe structure of a cryogenic liquid tank container according to claim 9, characterized in that: A chamber (29) with an enlarged diameter is provided in the middle of the connecting tube (25), and the floating core (28) moves in the enlarged chamber (29). The floating core (28) comprises an axial guide rod (30) and an inclined conical surface (31). The axial guide rod (30) is arranged along the axis through the inclined conical surface (31), and the inclined conical surface (31) cooperates with the sealing member (27). The floating valve structure (24) further comprises a guide frame (32), and the guide frame (32) is provided with a guide hole (33) for the axial guide rod (30) to pass through at least at the center of the connecting tube (25).

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