A rotary joint device for transporting cryogenic media

Abstract

The present invention relates to a rotary joint device for transporting cryogenic media. An annular first inner wall and a second inner wall are provided inside the rotary joint body. A cryogenic liquid-phase fluid channel flowing from top to bottom is formed inside the first inner wall, and a closed cryogenic gas-phase fluid channel is formed outside the second inner wall. A gas-phase fluid inlet pipe and a gas-phase fluid outlet pipe communicating with the inside of the cryogenic gas-phase fluid channel are fixedly connected to the outer shell of the rotary joint body. The fluid distribution and flow stabilization assembly includes a liquid-phase fluid distribution tube plate, a flow guiding assembly, and a backflow prevention assembly. The liquid-phase fluid distribution tube plate is horizontally fixed inside the top opening of the first inner wall, the flow guiding assembly is fixed inside the gas-phase fluid inlet pipe, and the backflow prevention assembly is fixed inside the gas-phase fluid outlet pipe. The present invention can complete the simultaneous transportation of cryogenic liquid-phase fluid and gas-phase fluid by using a single rotary joint device, and through the interaction of the liquid-phase fluid distribution tube plate, the flow guiding assembly, and the backflow prevention assembly, ensure stable flow inside the rotary joint and uniform fluid distribution.

Description

Technical Field

[0001] The present invention relates to the technical field of cryogenic medium transportation, and particularly relates to a rotary joint device for ultra-low temperature medium transportation. Background Art

[0002] A floating liquefied natural gas production storage and offloading unit (FLNG) is a floating production device used for the development of offshore gas fields. It is positioned offshore through a mooring system and has the functions of exploiting, processing, liquefying, storing, and loading and unloading natural gas. By cooperating with a liquefied natural gas (LNG) ship, it realizes the exploitation of offshore gas fields and the transportation of natural gas. The use of FLNG for offshore gas field development has ended the single mode of only using pipeline transportation to shore for offshore gas fields, saving transportation costs and not occupying onshore space.

[0003] An LNG unloading arm is a rigid articulated pipeline system installed on a wharf or FLNG for LNG unloading. Its main structure includes a rotary joint, an outer arm, an inner arm, a basic riser pipe, and process pipelines such as the rotary joint connecting the inner arm and the basic riser pipe, as well as its supporting structure and accessories. A large LNG unloading arm stands at the forefront of the LNG receiving terminal wharf area. As a key core equipment connecting the LNG ship with the onshore pipeline and storage facilities in the receiving terminal, it is the "throat" of the entire receiving terminal. When an LNG transport ship arrives at the dedicated wharf of the receiving terminal, through the liquid-phase unloading arm and the unloading pipeline, the LNG is sent into the storage tank of the receiving terminal by using the cryogenic pump on the ship. At the same time, the boil-off gas (BOG) in the storage tank returns to the LNG transport ship through the return gas pipeline and the gaseous return gas arm. During the operation of the LNG unloading arm, a towing line is used to guide the connection between the end of the unloading arm and the receiving end of the LNG ship to ensure accurate docking under relative movement conditions, and the hydraulic system of the unloading arm is controlled to enable it to withstand the influence of the speed and acceleration caused by the hull movement.

[0004] In view of the harsh sea conditions in the South China Sea of our country, if the existing mooring technology and traditional rigid unloading arms are difficult to effectively solve the problem of differential movement between the FLNG floating platform and the transport ship carrier, a specially designed cryogenic external unloading system is required to meet the stringent requirements of cryogenic and swaying working conditions. The cryogenic hose transportation system has obvious comprehensive advantages in terms of weight, flexibility, corrosion resistance, heat insulation, etc. When conducting FLNG external unloading operations, an effective method is to use tandem mooring, that is, to connect with the LNG transport ship through a mooring cable and use cryogenic hoses to achieve LNG unloading. It is required that the cryogenic hoses can withstand ultra-low temperatures and also overcome the influence of relative movement between the FLNG and the LNG transport ship.

[0005] In addition, the liquid hydrogen shipping test has been successfully implemented, providing a more economical and safe way for the liquid hydrogen industrial chain, which is of positive significance for the popularization and use of hydrogen energy globally and has strong development potential in the future. Liquid hydrogen has the characteristics of ultra-low temperature, easy volatilization, inflammability and explosiveness. The loading, unloading and transportation of liquid hydrogen between ship and shore are difficult, with high safety requirements and many technical barriers. The operating conditions of the liquid hydrogen ship-shore loading and unloading system are harsh, the action accuracy requirements are demanding, and the cooperation of the mechanical and electrical systems is complex. It is necessary to have functions such as quick docking, emergency disconnection, and automatic shutdown, and also withstand the long-term ultra-low temperature test of -253°C and automatically adapt to the influence of tidal drop.

[0006] In summary, the key technologies of cryogenic fluid transportation systems such as LNG rigid unloading arms, LNG cryogenic hose transmission systems, and liquid hydrogen ship-shore loading and unloading systems all involve many aspects such as the selection of cryogenic materials, forming manufacturing and sealing, and test verification. The material selection and structural design are difficult, the processing manufacturing and performance testing are difficult, the cryogenic sealing, connection and leakage monitoring are highly difficult, and the entire cryogenic transportation system has a complex structure and high safety requirements. Among them, the swivel joint is a key component, and its performance directly affects the safe and stable operation of the cryogenic fluid transportation system. As a key structural component for the flow of cryogenic media and providing steering, the swivel joint is required to prevent the leakage of cryogenic media, withstand high-intensity loads and pressures, and have low friction loss during rotation under ultra-low temperature dynamic conditions.

[0007] Currently, the swivel joint devices adopted in the existing technologies mainly have the following technical defects:

[0008] (1) When the swivel joint device adopted in the existing technology transports ultra-low temperature media, it is carried out separately for the liquid phase state and the gas phase state, that is, the corresponding swivel joints are configured for the liquid phase pipelines, and the same is true for the gas phase pipelines, making the ultra-low temperature transportation system more complex. Taking the above-mentioned LNG rigid unloading arm as an example, during the ship-shore loading and unloading of liquefied natural gas, LNG is transported from the transport ship to the onshore LNG storage facility through the liquid phase pipeline where the swivel joint is located. During this process, the BOG evaporation gas generated by the gasification of LNG still needs to be transported back to the transport ship along the opposite pipeline to balance the operating pressure between the ship and the shore. Therefore, multiple liquid phase pipeline swivel joints and gas phase pipeline swivel joints need to be set on the corresponding cryogenic transportation pipelines respectively, making the entire system structure complex and the system resources not being optimally configured;

[0009] (2) The prior art rotary joint device does not have corresponding insulation and cold-keeping protection measures during operation. Due to the ultra-low temperature working environment (for example, the LNG working temperature is -163°C, and the liquid hydrogen working temperature is -253°C), the temperature difference between the inside and outside of the flow-through components is large, which makes the external condensation and freezing of the rotary joint prominent. External freezing often occurs, resulting in mechanical failure of the rotary joint components (that is, external freezing causes the rotary joint device to get stuck and cannot work normally), seriously affecting the safe and stable operation of the cryogenic transportation system. At the same time, the large temperature difference between the inside and outside of the rotary joint also leads to high cold loss during the flow of LNG or liquid hydrogen, which manifests itself in that the liquid LNG inside the rotary joint is partially vaporized into gaseous natural gas, or liquid hydrogen is converted into gaseous hydrogen. This will lead to a very serious problem. During the vaporization process, the operating pressure inside the rotary joint rises sharply, causing the cryogenic transportation system to operate in an overpressure state, affecting the safe and stable operation of the system.

[0010] (3) It was found during the operation of the cryogenic transportation system that when LNG or liquid hydrogen flows inside the rotary joint, as well as during the transportation of gaseous natural gas or hydrogen, the flow of the cryogenic fluid inside the existing rotary joint is unstable, the flow distribution is uneven, the gas resistance is high, and the "backflow" phenomenon is serious. These are very unfavorable to the stable transportation of the system. The industry urgently needs to solve this key technical problem. Summary of the invention

[0011] The object of the present invention is to provide a rotary joint device for transporting ultra-low temperature media, so as to solve the above-mentioned problems existing in the prior art when using a rotary joint device to transport ultra-low temperature media.

[0012] To achieve the above object, the present invention adopts the following technical solutions:

[0013] The present invention provides a rotary joint device for transporting ultra-low temperature media, comprising:

[0014] A rotary joint body, wherein an annular first inner wall and a second inner wall are provided in the rotary joint body, a low-temperature liquid phase fluid channel flowing from top to bottom is formed in the first inner wall, the second inner wall is annularly arranged outside the first inner wall, and a closed low-temperature gas phase fluid channel is formed between the second inner wall and the outer shell of the rotary joint body, a gas phase fluid inlet pipe and a gas phase fluid outlet pipe connected to the low-temperature gas phase fluid channel are fixedly connected to the outer shell of the rotary joint body, and a vacuum layer is formed between the first inner wall and the second inner wall;

[0015] Fluid distribution and flow stabilization component, the fluid distribution and flow stabilization component includes a liquid-phase fluid distribution tube sheet, a flow guiding component, and a backflow prevention component. The liquid-phase fluid distribution tube sheet is horizontally fixed in the top opening of the first inner wall. The flow guiding component is fixed in the gas-phase fluid inlet pipe and is used for the intake air flow to enter the low-temperature gas-phase fluid channel in a swirling manner. The backflow prevention component is fixed in the gas-phase fluid discharge pipe.

[0016] Further, a first channel vertically penetrating up and down is provided in the middle of the liquid-phase fluid distribution tube sheet. A plurality of second channels vertically penetrating are provided on the liquid-phase fluid distribution tube sheet outside the first channel. The plurality of second channels are distributed along the circumferential direction of the first channel. A plurality of third channels vertically penetrating are provided on the liquid-phase fluid distribution tube sheet outside the second channel. The plurality of third channels are distributed along the circumferential direction of the first channel. An annular fourth channel is provided on the liquid-phase fluid distribution tube sheet outside the third channel. The fourth channel is vertically penetrating. The sum of the cross-sectional areas of several of the second channels is smaller than the cross-sectional area of the first channel. The sum of the cross-sectional areas of several of the third channels is smaller than the sum of the cross-sectional areas of several of the second channels. The cross-sectional area of the fourth channel is smaller than the sum of the cross-sectional areas of several of the third channels.

[0017] Further, the bottom of the liquid-phase fluid distribution tube sheet is a curved structure with a downward-opening longitudinal section.

[0018] Further, the flow guiding component includes a flow guiding cone and a plurality of flow guiding vanes fixedly connected to the outer wall of the flow guiding cone. The flow guiding cone is fixed in the gas-phase fluid inlet pipe through a bracket, and the cone end of the flow guiding cone faces the air inlet of the gas-phase fluid inlet pipe. The flow guiding vanes are fixedly arranged in an arc shape along the length direction of the flow guiding cone, and the plurality of flow guiding vanes are arranged in the same direction along the circumferential direction of the flow guiding cone.

[0019] Further, the angle between the vane of the flow guiding vane near the air inlet of the gas-phase fluid inlet pipe and the horizontal line at this position is 90°. The angle between the vane of the flow guiding vane near the air outlet of the gas-phase fluid inlet pipe and the horizontal line at this position ranges from 30° to 60°.

[0020] Further, the anti-backflow component includes an inlet section, a straight-through section, and a diffuser section that are sequentially defined on the inner wall of the gas-phase fluid discharge pipe from its inlet to its outlet. The inner diameter of the inlet section decreases sequentially from the inlet to the outlet of the gas-phase fluid discharge pipe. The inner diameter of the straight-through section remains unchanged. The inner diameter of the diffuser section increases sequentially from the inlet to the outlet of the gas-phase fluid discharge pipe. A plurality of annular grooves are formed on the inner wall of the gas-phase fluid discharge pipe from its inlet to its outlet. The annular grooves are inclined, so that the inner wall between two adjacent annular grooves forms an annular blade inclined in the direction of gas-phase fluid flow.

[0021] Further, the surface of the inlet section is an arc surface, the surface of the diffuser section is a conical surface. The width of the annular groove on the inlet section is greater than the width of the annular grooves on the straight-through section and the diffuser section. And the widths of several annular grooves on the diffuser section decrease sequentially from the inlet to the outlet of the gas-phase fluid discharge pipe. Wherein, the included angle between the concave surface or its tangent of the annular groove located in the straight-through section and the axis of the gas-phase fluid discharge pipe is set as angle C, and the included angle between the concave surface or its tangent of the annular groove located in the diffuser section and the conical surface in the diffuser section is set as angle D. The angle range of angle C and / or D is 40°-70°.

[0022] Further, an annular third inner wall is provided inside the rotary joint body. The third inner wall is circumferentially arranged outside the second inner wall. An annular and closed low-temperature gas-phase fluid channel is formed between the third inner wall and the second inner wall. An annular and closed heat-insulating filling layer is formed between the third inner wall and the outer shell of the rotary joint body. The heat-insulating filling layer is filled with heat-insulating materials.

[0023] Further, the rotary joint body includes an upper rotary joint and a lower rotary joint that are sequentially arranged from top to bottom. An annular first bearing jacket is fixedly connected to the outer edge of the bottom of the upper rotary joint. An annular second bearing jacket is fixedly connected to the outer edge of the top of the lower rotary joint. The first bearing jacket is arranged inside the second bearing jacket, and a ball bearing is clamped between the first bearing jacket and the second bearing jacket. Wherein, the first inner wall, the second inner wall, and the third inner wall are all interconnected by an annular upper cavity wall and an annular lower cavity wall. The upper cavity wall is fixed inside the upper rotary joint. The lower cavity wall is fixed inside the lower rotary joint. And a sealing ring is installed between the upper cavity wall and the lower cavity wall.

[0024] Due to the adoption of the above technical solutions, the present invention has the following beneficial effects:

[0025] 1. Through the innovative structural design of the rotary joint, by setting up the low-temperature liquid-phase fluid channel and the low-temperature gas-phase fluid channel, it is possible to complete the simultaneous transportation of low-temperature liquid-phase fluid and gas-phase fluid with one rotary joint device, featuring integrated integration and compact structure.

[0026] 2. By setting the vacuum layer between the first inner wall and the second inner wall, and the heat-insulating filling layer between the third inner wall and the outer shell of the rotary joint body, the rotary joint device of the present invention can effectively reduce the mechanical failure of the rotary joint components caused by ice formation due to the temperature difference inside and outside the flow-through components, and the problem that the ultra-low temperature liquid phase inside the rotary joint is vaporized into the gas phase, resulting in a sharp increase in the operating pressure inside the rotary joint, thus ensuring the safe and stable operation of the ultra-low temperature transportation system.

[0027] 3. Combining the principles of fluid mechanics and the analysis and practice of the prior art, through the matching setting and interaction of the liquid-phase fluid distribution tube plate, the flow guiding component, and the anti-backflow component, the internal flow of the rotary joint device is ensured to be stable, the fluid distribution is uniform, the gas resistance and the "backflow" phenomenon are reduced, and the defects of the prior art are overcome. Brief Description of the Drawings

[0028] By reading the detailed description of the preferred embodiments below, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention. Throughout the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0029] Figure 1 is the overall structural schematic diagram of a rotary joint device provided by an embodiment of the present invention;

[0030] Figure 2 is the structural schematic diagram of the liquid-phase fluid distribution tube plate of a rotary joint device provided by an embodiment of the present invention;

[0031] Figure 3 is the front view of the flow guiding component of a rotary joint device provided by an embodiment of the present invention;

[0032] Figure 4 is the top view of the flow guiding component of a rotary joint device provided by an embodiment of the present invention;

[0033] Figure 5 is the structural schematic diagram of the anti-backflow component of a rotary joint device provided by an embodiment of the present invention;

[0034] Figure 6 is the assembly structural schematic diagram of the sealing ring of a rotary joint device provided by an embodiment of the present invention.

[0035] The reference numerals in the drawings are represented as follows:

[0036] 1. Rotating joint body; 11. First inner wall; 111. First connecting flange; 112. Second connecting flange; 12. Second inner wall; 13. Low-temperature liquid-phase fluid channel; 14. Low-temperature gas-phase fluid channel; 15. Gas-phase fluid inlet pipe; 151. Third connecting flange; 16. Gas-phase fluid discharge pipe; 161. Fourth connecting flange; 17. Vacuum layer; 18. Third inner wall; 19. Heat-insulating filling layer; 2. Fluid distribution and flow stabilization assembly; 21. Liquid-phase fluid distribution tube sheet; 211. First channel; 212. Second channel; 213. Third channel; 214. Fourth channel; 22. Flow guiding assembly; 221. Flow guiding cone; 222. Flow guiding vane; 23. Anti-backflow assembly; 231. Inlet section; 232. Straight-through section; 233. Diffusion section; 234. Annular groove; 235. Annular vane; 3. Upper rotating joint; 31. First bearing housing; 4. Lower rotating joint; 41. Second bearing housing; 5. Ball bearing; 6. Sealing ring; 7. Sealing groove; 8. Receiving groove; 9. Compression spring. Detailed implementation mode

[0037] The exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0038] When using a traditional rotating joint device to transport cryogenic media, there are technical defects. The present invention provides a rotating joint device for transporting cryogenic media, including a rotating joint body and a fluid distribution and flow stabilization assembly. The rotating joint body is provided with independent low-temperature liquid-phase fluid channels and low-temperature gas-phase fluid channels, so that a rotating joint device can complete the simultaneous transportation of low-temperature liquid-phase fluid and gas-phase fluid. The fluid distribution and flow stabilization assembly includes a liquid-phase fluid distribution tube sheet, a flow guiding assembly, and an anti-backflow assembly. Through the matching setting and interaction of the liquid-phase fluid distribution tube sheet, the flow guiding assembly, and the anti-backflow assembly, the internal flow of the rotating joint device is ensured to be stable, the fluid distribution is uniform, and the gas resistance and "backflow" phenomenon are reduced.

[0039] The solution of the present invention will be described in detail below through examples.

[0040] Embodiment

[0041] As Figure 1 shown, the present invention provides a rotating joint device for transporting cryogenic media, including a rotating joint body 1 and a fluid distribution and flow stabilization assembly 2, and the specific settings are as follows:

[0042] An annular first inner wall 11 and a second inner wall 12 are provided inside the rotary joint body 1. A low-temperature liquid-phase fluid channel 13 flowing from top to bottom is formed inside the first inner wall 11. The second inner wall 12 is circumferentially arranged outside the first inner wall 11, and a closed low-temperature gas-phase fluid channel 14 is formed between the second inner wall 12 and the outer shell of the rotary joint body 1. A gas-phase fluid inlet pipe 15 and a gas-phase fluid outlet pipe 16 communicating with the inside of the low-temperature gas-phase fluid channel 14 are fixedly connected to the outer shell of the rotary joint body 1. Among them, a first connection flange 111 fixed to the top of the rotary joint body 1 is provided at the top opening of the first inner wall 11 for interconnecting with the upstream liquid-phase fluid pipeline; a second connection flange 112 fixed to the bottom of the rotary joint body 1 is provided at the bottom opening of the first inner wall 11 for interconnecting with the downstream liquid-phase fluid pipeline, so that low-temperature liquid-phase media such as LNG or liquid hydrogen from the upstream enter the inside of the rotary joint device along the low-temperature liquid-phase fluid channel 13 and enter the downstream pipeline. In addition, a third connection flange 151 is connected to the gas inlet of the gas-phase fluid inlet pipe 15 for interconnecting with the return pipeline of the gas-phase medium in the low-temperature transportation system; a fourth connection flange 161 is fixed at the gas outlet of the gas-phase fluid outlet pipe 16 for interconnecting with the downstream pipeline, so that the gas-phase medium that needs to be returned in the low-temperature transportation system enters the low-temperature gas-phase fluid channel 14 inside the rotary joint device through the gas-phase fluid inlet pipe 15 and is discharged through the gas-phase fluid outlet pipe 16 into the downstream pipeline connected thereto. Thus, by using one rotary joint device, the simultaneous transportation of low-temperature liquid-phase fluid and gas-phase fluid can be completed.

[0043] As described above, a vacuum layer 17 is formed between the first inner wall 11 and the second inner wall 12. Through the setting of this structure, the annular area formed between the first inner wall 11 and the second inner wall 12 is used as the vacuum layer 17 area, and the cryogenic liquid-phase medium is insulated by vacuum insulation. Vacuum is one of the most effective ways of cryogenic insulation, especially suitable for the technical conditions involved in the present invention. For example, the temperature of LNG is -163°C and the temperature of liquid hydrogen is -253°C. Thus, the ultra-low temperature inside the rotary joint device can be prevented from conducting to the outside, the vaporization of cryogenic liquids can be reduced, and the safety problems caused by internal overpressure can be effectively prevented.

[0044] Furthermore, an annular third inner wall 18 is provided in the rotary joint body 1. The third inner wall 18 is circumferentially arranged outside the second inner wall 12, so that an annular and closed low-temperature gas-phase fluid channel 14 is formed between the third inner wall 18 and the second inner wall 12, and an annular and closed heat-insulating filling layer 19 is formed between the third inner wall 18 and the outer shell of the rotary joint body 1. The heat-insulating filling layer 19 is filled with heat-insulating material. Among them, the heat-insulating material is preferably one of aerogel, three-polyester, elastic felt or glass wool. Since the temperature of the returned gas-phase medium is relatively low, usually the temperature of BOG or low-temperature hydrogen at this time is about -50 °C, so there is no need to adopt the vacuum heat-insulating method, and the piled heat insulation, that is, filling with the above-mentioned heat-insulating material, can meet the effect of cold insulation. Through this design, the filled cold-insulating material does not contact the low-temperature liquid-phase fluid, and the gas-phase medium is relatively safe, thus avoiding problems such as erosion and cold brittleness of the cold-insulating material caused by the existence of the low-temperature liquid-phase medium. Therefore, through the combined matching of the above-mentioned vacuum layer 17 and the heat-insulating filling layer 19, it is possible to prevent the internal and external temperature difference of the flow-through components from freezing and causing mechanical failures of the rotary joint components, and further ensure the safe and reliable operation of the low-temperature transportation system.

[0045] Combined Figure 2As shown, the fluid distribution and flow stabilization assembly 2 includes a liquid-phase fluid distribution tube sheet 21, a flow guiding assembly 22, and a backflow prevention assembly 23. The liquid-phase fluid distribution tube sheet 21 is horizontally fixed in the top opening of the first inner wall 11. Specifically, according to the law of fluid flow phenomena inside the rotary joint body 1, it is known that when LNG or liquid hydrogen flows inside the rotary joint body, the flow velocity along the axial direction close to the middle region is high and unstable, and the flow velocity along the edge region is relatively low but the flow is uneven. Therefore, according to the law of the flow, fluid distribution devices need to be set in the corresponding regions respectively. That is, a first channel 211 penetrating vertically up and down is provided in the middle of the liquid-phase fluid distribution tube sheet 21. A plurality of second channels 212 penetrating vertically are opened on the liquid-phase fluid distribution tube sheet 21 outside the first channel 211. The plurality of second channels 212 are distributed along the circumferential direction of the first channel 211. A plurality of third channels 213 penetrating vertically are opened on the liquid-phase fluid distribution tube sheet 21 outside the second channel 212. The plurality of third channels 213 are distributed along the circumferential direction of the first channel 211, and the cross-sections of the third channels 213 and the second channels 212 are both circular hole structures. An annular fourth channel 214 is opened on the liquid-phase fluid distribution tube sheet 21 outside the third channel 213. The fourth channel 214 is arranged to penetrate vertically. Among them, the sum of the cross-sectional areas of several second channels 212 is smaller than the cross-sectional area of the first channel 211, the sum of the cross-sectional areas of several third channels 213 is smaller than the sum of the cross-sectional areas of several second channels 212, and the cross-sectional area of the fourth channel 214 is smaller than the sum of the cross-sectional areas of several third channels 213. That is, the cross-sectional areas of the first channel 211 to the fourth channel 214 decrease in sequence. Since the fluid velocity is inversely proportional to the flow area, the setting of this structure can achieve a better flow velocity uniformity effect.

[0046] Furthermore, the bottom of the liquid-phase fluid distribution tube sheet 21 is a curve structure with a vertically downward opening in the longitudinal section. The curve can be one of an arc, an elliptical arc, or a parabola, which is specifically set after calculation according to the actual working conditions. And through practical verification, good fluid distribution and distribution effects can be achieved through the above structural design.

[0047] As described above, in combination with Figure 1 、 Figure 3 and Figure 4As shown in the figure, the flow guiding component 22 is fixed inside the gas-phase fluid inlet pipe 15 and is used to make the intake air flow enter the low-temperature gas-phase fluid channel 14 in a swirling manner. The anti-backflow component 23 is fixed inside the gas-phase fluid discharge pipe 16. Specifically, the flow guiding component 22 includes a flow guiding cone 221 and a plurality of flow guiding vanes 222 fixedly connected to the outer wall of the flow guiding cone 221. The flow guiding cone 221 is fixed inside the gas-phase fluid inlet pipe 15 through a bracket, and the conical end of the flow guiding cone 221 faces the air inlet of the gas-phase fluid inlet pipe 15. The flow guiding vanes 222 are fixedly arranged in an arc shape along the length direction of the flow guiding cone 221, and the plurality of flow guiding vanes 222 are arranged in the same direction along the circumferential direction of the flow guiding cone 221. Through the setting of this structure, when the intake air flow passes through the flow guiding vanes 222, rotation will be generated, and the intake air flow will enter the low-temperature gas-phase fluid channel 14 in a swirling manner. Since the low-temperature gas-phase fluid channel 14 is relatively narrow, the rotational force generated by the swirling manner can ensure the smooth flow of the gas medium in a relatively narrow space and avoid the "air resistance" effect. The preferred arrangement of the flow guiding vanes 222 is that the included angle A between the blade body of the flow guiding vane 222 close to the air inlet of the gas-phase fluid inlet pipe 15 and the horizontal line at this position is 90°, and the range of the included angle B between the blade body of the flow guiding vane 222 close to the air outlet of the gas-phase fluid inlet pipe 15 and the horizontal line at this position is 30° to 60°.

[0048] Combined with Figure 1 and Figure 5As shown in the figure, the anti-backflow component 23 includes an inlet section 231, a straight-through section 232, and a diffuser section 233 that are sequentially defined by the inner wall of the gas-phase fluid discharge pipe 16 from its inlet to its outlet. The inner diameter of the inlet section 231 decreases sequentially from the inlet to the outlet of the gas-phase fluid discharge pipe 16, the inner diameter of the straight-through section 232 remains unchanged, and the inner diameter of the diffuser section 233 increases sequentially from the inlet to the outlet of the gas-phase fluid discharge pipe 16. A plurality of annular grooves 234 are formed on the inner wall of the gas-phase fluid discharge pipe 16 from its inlet to its outlet. The annular grooves 234 are inclined, so that the inner wall between two adjacent annular grooves 234 forms an annular blade 235 that is inclined in the direction of the gas-phase fluid flow. Among them, the surface of the inlet section 231 is an arc surface, and the surface of the diffuser section 233 is a conical surface. The width of the annular groove 234 on the inlet section 231 is greater than the width of the annular groove 234 on the straight-through section 232 and the diffuser section 233, and the width of several annular grooves 234 on the diffuser section 233 decreases sequentially from the inlet to the outlet of the gas-phase fluid discharge pipe 16. Among them, the angle between the concave surface or its tangent of the annular groove 234 located in the straight-through section 232 and the axis of the gas-phase fluid discharge pipe 16 is set as angle C, and the angle between the concave surface or its tangent of the annular groove 234 located in the diffuser section 233 and the conical surface in the diffuser section 233 is set as angle D. The angle range of angle C and / or D is 40°-70°. Through the setting of this structure, by using the anti-backflow component 23 with annular grooves 234 and annular blades 235 on the inner wall of the gas-phase fluid discharge pipe 16, when the gas-phase medium flows along the gas-phase fluid discharge pipe 16 from the inlet to the outlet, the air flow resistance of the inner wall boundary layer can be reduced, which is beneficial to the flow of the gas-phase medium. At the same time, when reverse flow, that is, backflow phenomenon occurs in the gas-phase fluid discharge pipe 16, the structure of the annular groove 234 can cause a vortex effect during the reverse flow process, thereby greatly increasing the reverse air flow resistance, that is, it can reduce the gas backflow.

[0049] Based on the structural setting of the fluid distribution and flow stabilization component 2, through the matching setting and interaction of the above-mentioned liquid-phase fluid distribution pipe plate 21, the flow guiding component 22 and the anti-backflow component 23, the internal flow of the rotary joint device is ensured to be stable, the fluid distribution is uniform, the gas resistance and the "backflow" phenomenon are reduced, and the defects of the prior art are overcome.

[0050] A preferred implementation mode is: Looking back Figure 1, the swivel joint body 1 includes an upper swivel joint 3 and a lower swivel joint 4 which are arranged in sequence from top to bottom. An annular first bearing jacket 31 is fixedly connected to the outer edge of the bottom of the upper swivel joint 3, and an annular second bearing jacket 41 is fixedly connected to the outer edge of the top of the lower swivel joint 4. The first bearing jacket 31 is arranged inside the second bearing jacket 41, and the outer ring wall of the first bearing jacket 31 is closely attached to the inner ring wall of the second bearing jacket 41. A ball bearing 5 is clamped between the first bearing jacket 31 and the second bearing jacket 41. Preferably, a first clamping groove is formed on the outer ring wall of the first bearing jacket 31, and a second clamping groove corresponding to the first clamping groove is formed on the inner ring wall of the second bearing jacket 41. The upper and lower parts of the swivel joint body 1 can rotate circumferentially through the ball bearing 5, thereby enabling flexible adjustment of the directions of the pipelines where the air inlet direction and the air outlet direction are located.

[0051] As described above, in combination with Figure 1 and Figure 6 shown, the first inner wall 11, the second inner wall 12 and the third inner wall 18 are all interconnected by an annular upper cavity wall and an annular lower cavity wall. The upper cavity wall is fixed inside the upper swivel joint 3, the lower cavity wall is fixed inside the lower swivel joint 4, and a sealing ring 6 is embedded between the upper cavity wall and the lower cavity wall. Preferably, an annular sealing groove 7 is formed on the bottom end surface of the upper cavity wall, and an annular receiving groove 8 is formed on the inner bottom surface of the sealing groove 7. The sealing ring 6 is fitted and assembled in the sealing groove 7, and a plurality of pressing springs 9 are arranged along the circumferential direction in the receiving groove 8. Through the setting of this structure, after the upper swivel joint 3 and the lower swivel joint 4 are butted, the sealing ring 6 on the upper cavity wall tightly abuts against the top end surface of the lower cavity wall through the pressing spring 9 at the top, thereby achieving fixation and sealing. Among them, the material of the sealing ring 6 is preferably one of polytetrafluoroethylene, polyimide, and perfluoroethylene-propylene copolymer, which can meet the sealing requirements under cryogenic working conditions, and the sealing ring 6 enables relative rotation between the upper cavity wall and the lower cavity wall while still ensuring the sealing effect.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A rotary joint device for ultra-low temperature medium transportation, characterized in that The rotary joint device includes: A rotary joint body, in which an annular first inner wall and a second inner wall are provided. A low-temperature liquid-phase fluid channel flowing from top to bottom is formed inside the first inner wall. The second inner wall is circumferentially arranged outside the first inner wall, and a closed low-temperature gas-phase fluid channel is formed between the second inner wall and the outer shell of the rotary joint body. A gas-phase fluid inlet pipe and a gas-phase fluid outlet pipe communicating with the inside of the low-temperature gas-phase fluid channel are fixedly connected to the outer shell of the rotary joint body. A vacuum layer is formed between the first inner wall and the second inner wall; A fluid distribution and flow stabilization assembly, which includes a liquid-phase fluid distribution tube plate, a flow guiding assembly, and an anti-backflow assembly. The liquid-phase fluid distribution tube plate is horizontally fixed in the top opening of the first inner wall. The flow guiding assembly is fixed in the gas-phase fluid inlet pipe and is used for the intake air flow to enter the low-temperature gas-phase fluid channel in a swirling manner. The anti-backflow assembly is fixed in the gas-phase fluid outlet pipe; A first channel penetrating vertically up and down is provided in the middle of the liquid-phase fluid distribution tube plate. A plurality of second channels penetrating vertically are opened outside the first channel on the liquid-phase fluid distribution tube plate. The plurality of second channels are distributed along the circumferential direction of the first channel. A plurality of third channels penetrating vertically are opened outside the second channel on the liquid-phase fluid distribution tube plate. The plurality of third channels are distributed along the circumferential direction of the first channel. An annular fourth channel penetrating vertically is opened outside the third channel on the liquid-phase fluid distribution tube plate. The sum of the cross-sectional areas of several second channels is smaller than the cross-sectional area of the first channel. The sum of the cross-sectional areas of several third channels is smaller than the sum of the cross-sectional areas of several second channels. The cross-sectional area of the fourth channel is smaller than the sum of the cross-sectional areas of several third channels.

2. The rotating joint device for ultra-low temperature medium transportation according to claim 1, characterized in that: The bottom of the liquid-phase fluid distribution tube plate has a curved structure with a downward-opening longitudinal section.

3. The rotary joint device for ultra-low temperature medium transportation according to claim 1, wherein: The flow guiding assembly includes a flow guiding cone and a plurality of flow guiding vanes fixedly connected to the outer wall of the flow guiding cone. The flow guiding cone is fixed in the gas-phase fluid inlet pipe through a bracket, and the cone end of the flow guiding cone faces the air inlet of the gas-phase fluid inlet pipe. The flow guiding vanes are fixedly arranged in an arc along the length direction of the flow guiding cone, and the plurality of flow guiding vanes are arranged in the same direction along the circumferential direction of the flow guiding cone.

4. The rotary joint device for ultra-low temperature medium transportation according to claim 3, characterized in that: The included angle between the vane body of the flow guiding vane near the air inlet of the gas-phase fluid inlet pipe and the horizontal line at this position is 90°. The included angle range between the vane body of the flow guiding vane near the air outlet of the gas-phase fluid inlet pipe and the horizontal line at this position is 30° - 60°.

5. The rotating joint device for ultra-low temperature medium transportation according to claim 4, characterized in that: The anti-backflow component includes an inlet section, a straight-through section, and a diffuser section that are sequentially divided from the inner wall of the gas-phase fluid discharge pipe in the direction from its inlet to its outlet. The inner diameter of the inlet section decreases sequentially in the direction from the inlet of the gas-phase fluid discharge pipe to its outlet. The inner diameter of the straight-through section remains unchanged. The inner diameter of the diffuser section increases sequentially in the direction from the inlet of the gas-phase fluid discharge pipe to its outlet. A plurality of annular grooves are formed on the inner wall of the gas-phase fluid discharge pipe in the direction from its inlet to its outlet. The annular grooves are inclined, so that the inner wall between two adjacent annular grooves forms an annular blade inclined in the direction of gas-phase fluid flow.

6. The rotary joint device for ultra-low temperature medium transportation according to claim 5, characterized in that: The surface of the inlet section is an arc surface, and the surface of the diffuser section is a conical surface. The width of the annular grooves on the inlet section is greater than the width of the annular grooves on the straight-through section and the diffuser section. Moreover, the width of several annular grooves on the diffuser section decreases sequentially in the direction from the inlet of the gas-phase fluid discharge pipe to its outlet. Among them, the angle between the concave surface or its tangent line of the annular groove located in the straight-through section and the axis of the gas-phase fluid discharge pipe is set as angle C, and the angle between the concave surface or its tangent line of the annular groove located in the diffuser section and the conical surface in the diffuser section is set as angle D. The angle range of angle C and / or D is 40°-70°.

7. The rotating joint device for ultra-low temperature medium transportation according to claim 1, characterized in that: An annular third inner wall is provided inside the rotary joint body. The third inner wall is circumferentially arranged outside the second inner wall. An annular and closed low-temperature gas-phase fluid channel is formed between the third inner wall and the second inner wall. An annular and closed heat-insulating filling layer is formed between the third inner wall and the outer shell of the rotary joint body. The heat-insulating filling layer is filled with heat-insulating materials.

8. The rotating joint device for ultra-low temperature medium transportation according to claim 7, characterized in that: The rotary joint body includes an upper rotary joint and a lower rotary joint that are sequentially arranged from top to bottom. An annular first bearing jacket is fixedly connected to the outer edge of the bottom of the upper rotary joint. An annular second bearing jacket is fixedly connected to the outer edge of the top of the lower rotary joint. The first bearing jacket is arranged inside the second bearing jacket, and a ball bearing is clamped between the first bearing jacket and the second bearing jacket. Among them, the first inner wall, the second inner wall, and the third inner wall are all interconnected by an annular upper cavity wall and an annular lower cavity wall. The upper cavity wall is fixed inside the upper rotary joint, the lower cavity wall is fixed inside the lower rotary joint, and a sealing ring is installed between the upper cavity wall and the lower cavity wall.

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