Coaxial spiral magnetic field liquid metal driving device and method

Abstract

The invention discloses a coaxial spiral magnetic field liquid metal driving device and method, the device comprises a liquid metal flow channel part and a rotary driving coupling mechanism, and the liquid metal flow channel part comprises a shell with thin-wall structures on the two sides and a spiral partition; the interval between the two layers of thin walls of the shell is an annular area, the spiral partitions are arranged along the annular area, the annular area is divided into a plurality of parallel spiral cavities, and a spiral liquid metal flow channel used for flowing of liquid metal is formed; the rotary driving coupling mechanism comprises a sleeve structure and a driving part, an outer cylinder of the sleeve structure is arranged outside the shell in a sleeving mode through a rotary connecting piece, and the outer cylinder rotates through the driving part; the permanent magnets are evenly embedded on the outer cylinder in an array mode, N poles and S poles of the permanent magnets are arranged at intervals, liquid metal is driven to flow in the spiral flow channel in an accelerated mode through Lorentz force generated by a staggered magnetic field formed between a magnetic field and an electric field in the strong permanent magnet rotating process, and the effect can be achieved without adding alternating current and any coil.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid metal driving, and specifically to a coaxial spiral magnetic field liquid metal driving device and method. Background Art

[0002] Liquid metal has good fluidity, high thermal conductivity, and high electrical conductivity. Its heat transport capacity is much higher than that of water, air, and many non-metallic media, which will break the performance limit of traditional cooling technologies and is expected to play an important role in the cooling and thermal management systems in fields such as national defense, aerospace, energy systems, and civilian electronic devices.

[0003] At the same time, the fourth-generation fast neutron liquid metal nuclear reactor, as a potential advanced nuclear power generation technology, has received extensive attention. The reactor uses liquid metal (such as sodium, lead, etc.) as the coolant, which can not only maintain stable thermophysical properties at high temperatures but also dissipate heat efficiently and achieve higher fuel utilization. The use of liquid metal coolant is one of its main advantages, but it also brings challenges to the drive system, especially how to achieve efficient and reliable hydrodynamic control in the liquid metal circulation system.

[0004] The liquid metal driving device is a key component that provides driving force for the thermal management system or liquid metal circulation system of liquid metal. According to the different physical and chemical properties of liquid metal, there are various forms to control its movement and deformation, and different driving technologies are applicable to different temperature ranges, structural sizes, and application scenarios. However, liquid metal driving technologies, such as thermal driving and electrochemical driving, are not yet fully mature. Traditional mechanical pumps usually rely on electric motors for driving. At high temperatures, the corrosion and abrasion of mechanical pumps are serious, which poses high requirements for the corrosion resistance of the pump blades. Electromagnetic pumps, on the other hand, drive fluid flow through electromagnetic force, with less mechanical wear and higher reliability. In the application of the fourth-generation fast neutron metal nuclear reactor, in order to reduce the maintenance requirements of pumping equipment and improve the stability of the system, the adoption of permanent magnet driving technology has become an ideal solution.

[0005] The permanent magnet driving technology generates a magnetic field through permanent magnets to drive the rotation of the pump body or the flow of fluid, with advantages such as high efficiency, low noise, low energy consumption, and long service life. Compared with the traditional electric motor driving system, permanent magnet driving can not only avoid equipment shutdown caused by motor failures but also reduce the energy loss of the cooling system, thereby improving the performance and reliability of the overall system. Electromagnetic driving and thermal driving are used to drive liquid metal. Due to its high electrical conductivity advantage, liquid metal can be easily pumped into large thermal management systems, including nuclear power plants, concentrating solar power generation, and high-temperature energy storage.

[0006] However, existing traditional liquid metal driving technologies, such as pressure driving and electromagnetic field driving, are prone to problems such as unstable flow, low control accuracy, inconvenient start and stop, and easy corrosion. The root causes of these problems are mainly reflected in the design defects of traditional mechanical pumps and electromagnetic pumps. Traditional mechanical pumps rely on rotating blades to push the flow of liquid metal. However, due to the flow characteristics of high-temperature metal and the mechanical structure inside the pump, the flow is likely to become uneven. Especially in complex flow channels, eddy currents or local flow imbalances may occur, affecting the stability of the flow. At the same time, the blades and other moving parts of the pump are prone to wear during long-term operation, resulting in a decrease in the flow rate control accuracy, and the performance of the pump will also decline due to wear or corrosion. Mechanical pumps also rely on the rotation of electric motors and mechanical components, with a slow start and stop process and may generate large mechanical shocks, affecting the smooth operation of the system. While electromagnetic pumps control the flow of liquid metal through electromagnetic fields, it is difficult to ensure the control accuracy when the electromagnetic field configuration is unstable or affected by external environmental interference, which in turn leads to uneven and unstable flow. Summary of the Invention

[0007] The purpose of the present invention is to provide a coaxial spiral magnetic field liquid metal driving device and method, which has a high pump power, can be started and stopped at any time, and has good scalability.

[0008] The technical solution of the present invention is as follows:

[0009] A coaxial spiral magnetic field liquid metal driving device includes: a liquid metal flow channel part, including: a housing, which is a tubular structure with two thin walls. There is an interval space between the two thin walls on both sides of the housing, and the interval space is an annular region; at least two spiral partition plates, evenly distributed along the annular region, dividing the annular region into multiple parallel spiral cavities to form a spiral liquid metal flow channel for the flow of liquid metal; the spiral partition plates adopt a spiral small lead angle structure to provide a stable flow path for guiding the liquid metal to flow along a predetermined spiral flow channel; the introduction of the spiral partition plates optimizes the flow path of the liquid metal, improves the stability and efficiency of the flow, and thus improves the overall performance of the device. A rotation driving coupling mechanism, including: a sleeve structure and a driving part, the sleeve structure includes: an outer cylinder, which is rotatably sleeved outside the housing through a rotating connecting piece, and there is a gap between the inner wall of the outer cylinder and the outer wall of the housing, and the outer cylinder is rotated by the driving part; a plurality of permanent magnets, evenly embedded on the outer cylinder in an array form, with the N poles and S poles of the plurality of permanent magnets arranged at intervals, and the arrangement of the plurality of permanent magnets corresponds to the spiral geometric shape of the small lead angle of the spiral liquid metal flow channel, so that the magnetic field can cover the liquid metal area of the flow channel. And under the action of the spiral partition plates, the flow direction of the liquid metal is changed, increasing the axial component velocity, so that the flow of the liquid metal is controlled and can flow along the designed path.

[0010] Further, the rotating connector is a thin-walled bearing. The inner ring of the thin-walled bearing is sleeved between the sleeve structure and the liquid metal flow channel part, and the thin-walled bearing is used to bear radial loads.

[0011] Further, the driving part includes: a motor; a bevel gear pair including a first gear and a second gear. The first gear is sleeved on the motor shaft of the motor, the second gear is sleeved on one end of the outer cylinder, and the first gear and the second gear are meshed.

[0012] Further, the gear shafts of the first gear and the second gear are perpendicularly arranged, which changes the transmission direction, saves space, improves the transmission efficiency, effectively simplifies the device structure, enhances the compactness and operation stability of the device, and optimizes the overall layout design of the system.

[0013] Further, the liquid metal is any one of liquid sodium at high temperature, liquid lead at high temperature, and liquid lead-bismuth at high temperature, or a gallium-based alloy that is liquid at room temperature, such as gallium alloy, indium alloy, tin alloy, and zinc alloy. Among them, the high temperature state is 200°C - 300°C, and the room temperature state is 20°C - 30°C.

[0014] Further, a method for driving liquid metal by a coaxial spiral magnetic field liquid metal driving device includes the following steps:

[0015] When the liquid metal flow channel is empty, start the driving part to rotate the sleeve structure, and use the magneto-thermal coupling during the rotation of the permanent magnet to heat the shell of the liquid metal flow channel. The heat generated by the magneto-thermal coupling makes the flow channel in a temperature range suitable for liquid metal filling and flowing; when the liquid metal flow channel is filled with solid metal, start the driving part, and melt and heat the metal in the liquid metal flow channel to a set temperature under the action of magneto-thermal coupling; when the liquid metal flow channel is filled with liquid metal, start the driving to directly drive the liquid metal.

[0016] Further, when the driving part works, it drives the outer cylinder inlaid with multiple permanent magnets to rotate. Under the action of electromagnetic induction, eddy currents are generated in the liquid metal. The new magnetic field generated by the reverse eddy currents is misaligned with the original magnetic field in the permanent magnet, and a torque is formed under the action of the generated oblique electromagnetic force, pushing the liquid metal to flow circumferentially and obliquely along the annular liquid metal flow channel. The channel driving part realizes different rotation speeds and driving forces; when the cycle ends, gradually reduce the rotation speed of the outer cylinder inlaid with permanent magnets through the driving part to make the liquid metal flow smoothly transition.

[0017] Furthermore, a plurality of permanent magnets are arranged equidistantly on the outer cylinder surface in a multi-ring annular array along the axial direction of the outer cylinder, and the number of rings of the permanent magnets arranged can be adjusted according to the requirements of flow rate and pressure difference to achieve multi-stage acceleration and raise the flow rate and pressure difference to a higher level.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] 1. The present invention utilizes the misaligned magnetic field formed between the magnetic field and the electric field during the rotation of the strong permanent magnet to generate the Lorentz force to drive the flow of the liquid metal. The driving part drives the rotation of the sleeve structure of the uniform permanent magnet array composed of a plurality of permanent magnets. Under the action of electromagnetic induction, eddy currents are generated in the liquid metal. The eddy currents generate a new magnetic field, which is misaligned with the magnetic field in the permanent magnet, thereby generating an oblique electromagnetic force. Under the action of the oblique tangential force, a torque is formed to drive the liquid metal in the annular rotating flow channel to flow obliquely in the circumferential direction. Different from electromagnetic drive in essence, the present invention only needs the misaligned magnetic field formed by the rotation of the permanent magnet to drive, and can be realized without applying high-frequency alternating current and any coils. There is no need to introduce additional power equipment to the driving component, and the whole is compact and small in volume.

[0020] 2. The spiral partition plates of the present invention are uniformly distributed in the annular area of the two-layer thin-walled structure housing and are used to provide a path for the flow of the liquid metal; and the spiral partition plates adopt a spiral small lift angle structure design, which can provide a stable flow path and guide the liquid metal to flow along the predetermined spiral flow channel; the flow path of the liquid metal is optimized, and the stability and efficiency of the flow are improved, thereby improving the overall performance of the device. And through the design of the spiral-shaped liquid metal flow channel of the present invention, the flow channel closely surrounds the inner side of the magnetic pole, and the driving part drives the liquid metal to circulate through transmission, so that the whole system is more simplified and the structure is more compact. At the same time, the present invention can increase the number of rings or the overall length of the permanent magnets arranged according to the requirements of flow rate and pressure difference to achieve multi-stage acceleration and raise the flow rate and pressure difference to a higher level.

[0021] 3. The liquid metal of the present invention can select liquid sodium, liquid lead, liquid lead-bismuth at high temperature, or can also select gallium-based alloys (such as gallium-indium-tin-zinc (Ga-In-Sn-Zn) alloy) that are liquid at room temperature as the circulating working medium, which can meet the requirements of various energy and power engineering systems and has greater flexibility and reliability.

[0022] 4. The spiral liquid metal flow channel of the present invention can be directly connected to other transmission pipelines or devices in the liquid metal circulation system. By connecting the coaxial permanent magnet structure and the spiral flow channel through a suitable transmission system, the whole device is made compact and efficient. The coaxial permanent magnet structure improves the transmission efficiency, reduces the system complexity, reduces unnecessary friction by reducing misalignment and non-alignment between mechanical components, and extends the service life of the device. The bevel gear pair can change the power direction and maintain stability under high load. The combination of the two enables the device to operate efficiently and stably in a smaller space, with high reliability and a long service life. In addition, the forced circulation of liquid metal and the forced convection of air flow are simultaneously realized, enhancing the heat dissipation of liquid metal to the environment, thus effectively realizing the heat dissipation and low power consumption characteristics under ultra-high heat flux density. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a front view structural schematic diagram of the present invention.

[0024] Figure 2 It is a longitudinal sectional structural schematic diagram of the present invention.

[0025] Figure 3 It is Figure 2 An enlarged view of the structural schematic diagram of the thin-wall bearing area in

[0026] Figure 4 It is a transverse sectional structural schematic diagram of the present invention.

[0027] Figure 5 It is Figure 4 An enlarged view of the structural schematic diagram of the sleeve structure and the partial structure of the liquid metal flow channel in

[0028] Figure 6 It is an exploded view of the structural schematic diagram of the present invention.

[0029] Among them, 1. Liquid metal flow channel, 2. Spiral separator, 3. Thin-wall bearing, 4. Permanent magnet, 5. Outer cylinder, 6. Motor shaft, 7. Bevel gear pair, 8. Motor, 9. Liquid metal. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The following combines Figures 1 to 6 , and describes the specific embodiments of the present invention in detail. In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0031] The terms "first" and "second" are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features; in the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more than two.

[0032] It should be noted that the rotational speed control of the motor and the meshing connection of the gears involved in the present invention both adopt conventional technical means and do not involve any innovation.

[0033] Embodiment

[0034] A coaxial spiral magnetic field liquid metal driving device, comprising: a liquid metal flow channel part and a rotating mechanism, as Figure 1 , Figure 2 and Figure 3 shown, the liquid metal flow channel part includes: a housing and at least two spiral partition plates 2. The housing is a two-layer thin-walled tubular structure, and there is an interval space between the two thin walls on both sides of the housing. The interval space is an annular region; a plurality of spiral partition plates 2 are evenly distributed along the annular region, dividing the annular region into a plurality of parallel spiral cavities to form a spiral liquid metal flow channel for the liquid metal to flow; the spiral partition plates 2 adopt a spiral small lift angle structure to provide a stable flow path for guiding the liquid metal to flow along a predetermined spiral flow channel; the introduction of the spiral partition plates optimizes the flow path of the liquid metal, improves the stability and efficiency of the flow, thereby improving the overall performance of the device; as Figure 3 and Figure 4 shown, the rotary drive coupling mechanism includes: a sleeve structure and a drive part. The sleeve structure includes: an outer cylinder 5, which is rotatably sleeved outside the housing through a rotating connecting piece, and there is a gap between the inner wall of the outer cylinder 5 and the outer wall of the housing. The outer cylinder 5 rotates through the drive part; a plurality of permanent magnets 4 are evenly embedded on the outer cylinder 5 in an array form, and the N poles and S poles of the plurality of permanent magnets are arranged at intervals. The arrangement of the plurality of permanent magnets 4 corresponds to the spiral geometric shape of the small lift angle of the spiral liquid metal flow channel, so that the magnetic field can cover the liquid metal area of the flow channel. And under the action of the spiral partition plates 2, the flow direction of the liquid metal is changed, increasing the axial component velocity, so that the flow of the liquid metal is controlled and can flow along the designed path, realizing the efficient drive and precise control of the liquid metal, reducing the irregular flow phenomenon, and making the drive of the liquid metal more stable and efficient.

[0035] In some embodiments, the rotating connecting piece is a thin-walled bearing 3. The inner ring of the thin-walled bearing 3 is sleeved between the sleeve structure and the liquid metal flow channel part. The thin-walled bearing 3 is used to bear the radial load so that the housing rotates around its central axis.

[0036] In some embodiments, as Figure 1 shown, the driving part includes: a motor 8 and a bevel gear pair 7. The bevel gear pair 7 includes a first gear and a second gear. The first gear is sleeved on the motor shaft 6 of the motor 8, and the second gear is sleeved on one end of the outer cylinder 5, and the first gear and the second gear are meshed.

[0037] As Figure 1 and Figure 4 shown, the gear shafts of the first gear and the second gear are perpendicularly arranged. It changes the transmission direction, saves space, improves the transmission efficiency, effectively simplifies the device structure, enhances the compactness and operation stability of the device, and optimizes the overall layout design of the system.

[0038] In some embodiments, the liquid metal 9 adopts any one of liquid sodium at high temperature, liquid lead at high temperature, and liquid lead-bismuth at high temperature, or a gallium-based alloy that is liquid at room temperature can also be selected. Such as the gallium-indium-tin-zinc Ga-In-Sn-Zn alloy, which can meet the requirements of various energy and power engineering systems and has greater flexibility and reliability. Among them, the high temperature state is 200°C - 300°C, and the room temperature state is 20°C - 30°C.

[0039] A method for driving liquid metal by the above-mentioned coaxial spiral magnetic field liquid metal driving device includes the following steps:

[0040] When the liquid metal flow channel 1 is empty, start the driving part to rotate the sleeve structure, and use the magnetothermal coupling during the rotation of the permanent magnet to heat the shell of the liquid metal flow channel. The heat generated by the magnetothermal coupling makes the flow channel in the temperature range suitable for liquid metal filling and flowing; when the liquid metal flow channel 1 is filled with solid metal, start the driving part, and melt and heat the metal in the liquid metal flow channel 1 to the set temperature under the action of magnetothermal coupling; when the liquid metal flow channel 1 is filled with liquid metal, start the driving to directly drive the liquid metal 9.

[0041] When the driving part works, the motor 8 starts, drives the first gear of the bevel gear pair 7 to rotate, drives the outer cylinder 5 embedded with a plurality of permanent magnets 4 to rotate through the second gear. Under the action of electromagnetic induction, eddy currents are generated in the liquid metal 9. The new magnetic field generated by the reverse eddy currents is misaligned with the original magnetic field in the permanent magnet, and a torque is formed under the action of the generated oblique electromagnetic force, pushing the liquid metal 9 to flow circumferentially and obliquely along the annular liquid metal flow channel 1. Adjust the frequency of the motor 8 to achieve different rotational speeds and driving forces;

[0042] When the cycle ends, gradually reduce the rotational speed of the motor 8 to ensure that the rotational speed of the outer cylinder 5 embedded with the permanent magnets 4 gradually slows down, so that the flow of the liquid metal 9 transitions smoothly; after the liquid metal circulation slows down to a safe level, cut off the power supply to ensure safe shutdown.

[0043] In some embodiments, a plurality of permanent magnets 4 are arranged equidistantly on the surface of the outer cylinder 5 in a multi-loop annular array along the axial direction of the outer cylinder 5, and the number of loops in which the permanent magnets 4 are arranged can be adjusted according to the requirements of flow rate and pressure difference. To achieve multi-stage acceleration and raise the flow rate and pressure difference to a higher level.

[0044] The above-disclosed are only several preferred specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto, and any changes that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A coaxial spiral magnetic field liquid metal driving device, characterized in that Comprising: A liquid metal flow channel part, comprising: a housing, which is a tubular structure with two layers of thin walls, there is a spaced space between the two thin walls on both sides of the housing, and the spaced space is an annular region; at least two spiral partition plates (2), which are evenly distributed along the annular region, dividing the annular region into a plurality of parallel spiral cavities to form a spiral liquid metal flow channel for liquid metal flow; the spiral partition plates (2) adopt a spiral small lead angle structure for guiding the liquid metal to flow along a predetermined spiral flow channel. A rotary drive coupling mechanism, comprising: a sleeve structure and a drive part, the sleeve structure comprising: an outer cylinder (5), which is rotatably sleeved outside the housing through a rotating connecting piece, and there is a gap between the inner wall of the outer cylinder (5) and the outer wall of the housing, and the outer cylinder (5) rotates through the drive part; a plurality of permanent magnets (4), which are evenly embedded on the outer cylinder (5) in an array form, the N poles and S poles of the plurality of permanent magnets are arranged at intervals, and the arrangement of the plurality of permanent magnets (4) corresponds to the spiral geometric shape of the small lead angle of the spiral liquid metal flow channel, so that the magnetic field can cover the liquid metal area of the flow channel.

2. The coaxial spiral magnetic field liquid metal driving device according to claim 1, characterized in that, The rotating connecting piece is a thin-walled bearing (3), the inner ring of the thin-walled bearing (3) is sleeved between the sleeve structure and the liquid metal flow channel part, and the thin-walled bearing (3) is used to bear radial loads.

3. A coaxial spiral magnetic field liquid metal driving device according to claim 1, characterized in that The drive part comprises: A motor (8); A bevel gear pair (7), comprising a first gear and a second gear, the first gear is sleeved on the motor shaft (6) of the motor (8), the second gear is sleeved on one end of the outer cylinder (5), and the first gear and the second gear are meshed.

4. A coaxial spiral magnetic field liquid metal driving device according to claim 3, characterized in that, The gear shafts of the first gear and the second gear are perpendicularly arranged.

5. A coaxial spiral magnetic field liquid metal driving device according to claim 1, characterized in that, The liquid metal (9) adopts any one of liquid sodium at a high temperature, liquid lead at a high temperature, and liquid lead-bismuth at a high temperature.

6. A method for driving liquid metal by a coaxial spiral magnetic field liquid metal driving device according to any one of claims 1-5, characterized in that, Comprising the following steps: When the liquid metal flow channel (1) is empty, start the drive part to rotate the sleeve structure, and use the magneto-thermal coupling during the rotation of the permanent magnet to heat the housing of the liquid metal flow channel, so that the flow channel is in a temperature range suitable for liquid metal filling and flowing through the heat generated by the magneto-thermal coupling; when the liquid metal flow channel (1) is filled with solid metal, start the drive part, and melt and heat the metal in the liquid metal flow channel (1) to a set temperature under the action of magneto-thermal coupling; when the liquid metal flow channel (1) is filled with liquid metal, start the drive to directly drive the liquid metal (9).

7. A method for driving liquid metal by a coaxial spiral magnetic field liquid metal driving device according to claim 6, characterized in that, When the drive part works, it drives the outer cylinder (5) embedded with a plurality of permanent magnets (4) to rotate. Under the action of electromagnetic induction, eddy currents are generated in the liquid metal (9). The new magnetic field generated by the reverse of the eddy currents is misaligned with the original magnetic field in the permanent magnet, and a torque is generated under the action of the generated oblique electromagnetic force to push the liquid metal (9) to flow circumferentially and obliquely along the annular liquid metal flow channel (1), and different rotation speeds and driving forces are realized through the channel drive part. When the cycle ends, gradually reduce the rotation speed of the outer cylinder (5) embedded with the permanent magnets (4) through the drive part to enable the liquid metal (9) to flow smoothly.

8. A method for driving liquid metal by a coaxial spiral magnetic field liquid metal driving device according to claim 7, characterized in that, A plurality of permanent magnets (4) are arranged equidistantly on the surface of the outer cylinder (5) in a multi-turn annular array along the axial direction of the outer cylinder (5), and the number of turns of the permanent magnets (4) arranged can be adjusted according to the requirements of flow rate and pressure difference.

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