Modular low voltage switchgear suitable for smart grid

Abstract

This invention discloses a modular low-voltage switchgear suitable for smart grids, belonging to the field of low-voltage switchgear technology. It includes a cabinet with multiple module slots inside, each containing multiple auxiliary heat transfer components. Drawer units are installed within the module slots, and each drawer unit is equipped with a breathing heat dissipation unit. This invention replaces the rigid sealing structure with a multi-layer corrugated metal diaphragm assembly. It utilizes the corrugated elastic compression to absorb impact energy, automatically quenching flames through interlayer slits, and leverages the evaporation and condensation cycle of the phase change working fluid to achieve efficient heat conduction without occupying the internal installation space of the drawer unit. This solves the problem of limited heat dissipation capacity in explosion-proof switchgear. Furthermore, by mixing magnetic particles into the liquid phase change working fluid, the boundary layer is disturbed under the drive of the auxiliary heat transfer components, promoting bubble generation and detachment, significantly enhancing the nucleation boiling heat transfer coefficient.

Description

Technical Field

[0001] This invention relates to the field of low-voltage switchgear technology, and more particularly to a modular low-voltage switchgear suitable for smart grids. Background Technology

[0002] Modular low-voltage switchgear (also known as drawer-type low-voltage switchgear) adopts a modular design and drawer-type structure, integrating each electrical circuit into an independent drawer unit. Each drawer unit is electrically isolated, and during maintenance, only the faulty drawer needs to be removed without interrupting power to other circuits. This "hot-swappable" characteristic greatly improves the continuity and maintainability of industrial power distribution systems and has been widely used in heavy industries such as petroleum, chemical, metallurgy, and coal mining. Explosion-proof switchgear operates on the principle of encapsulating electrical components inside the switchgear that may generate sparks, arcs, or dangerous temperatures within a sufficiently strong housing. This housing can withstand the pressure generated when the internal explosive mixture explodes and prevents the flame from spreading outwards. However, to achieve this goal, existing modular low-voltage switchgear typically uses a thick metal shell, a small gap between joint surfaces, and a long flame path length, requiring high overall sealing performance. This explosion-proof design, which focuses on sealing and a thick shell, contradicts the heat dissipation requirements of the internal components of the switchgear. Meanwhile, in explosion-proof equipment, any heat dissipation channel that penetrates the housing must undergo a complex explosion-proof joint surface design, which increases the size and weight of existing drawer units, and the channel itself becomes a flame propagation path, making it difficult to meet the stringent explosion-proof standards. Summary of the Invention

[0003] The purpose of this invention is to solve the problem that existing low-voltage switchgear cannot simultaneously meet the requirements of explosion-proof safety and efficient heat dissipation, and to propose a modular low-voltage switchgear suitable for smart grids.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A modular low-voltage switchgear suitable for smart grids includes a cabinet, the cabinet having multiple module slots, multiple auxiliary heat transfer components in the module slots, and a drawer unit installed in the module slots. The drawer unit includes a main housing, the top of the main housing having a cover plate, components inside the main housing, and multiple rectangular mounting openings on both sides of the main housing and the top of the cover plate, with a breathing heat dissipation unit installed in the mounting opening. The breathing and heat dissipation unit includes a frame, within which a multi-layer corrugated metal diaphragm assembly is provided. The corrugated metal diaphragm assembly is filled with a liquid phase change working fluid, which is composed of a mixture of a low-boiling-point dielectric liquid and magnetic particles. The auxiliary heat transfer component includes multiple sets of paired rotating rods and rectangular slots opened in the module slots. The shape and position of the rectangular slots match the frame, and neodymium magnets are provided on the shaft of the rotating rods.

[0005] As a preferred embodiment, the multilayer corrugated metal diaphragm assembly is composed of multiple metal foils, with a perforated spacer layer between adjacent metal foils to maintain the interlayer gap. The edges of each metal foil layer are sealed to the inner peripheral wall of the frame by welding, and the surface of the metal foil is pressed with a periodically distributed corrugated structure.

[0006] As a preferred embodiment, the trough area of ​​the corrugated structure faces the inside of the drawer unit to form an evaporation heat absorption zone, and the crest area of ​​the corrugated structure faces the outside of the drawer unit to form a condensation heat release zone. The corrugated structure located inside the multi-layer corrugated metal diaphragm assembly is arranged in parallel along the surface of the metal foil, so that the grooves between adjacent corrugations form a capillary reflux channel.

[0007] As a preferred embodiment, the equivalent hydraulic diameter of the capillary reflux channel is set to be able to drive the condensed liquid phase change working fluid to reflux from the condensation section to the evaporation section by utilizing surface tension, thereby realizing working fluid circulation without external power.

[0008] As a preferred embodiment, the two rotating rods are arranged in parallel, one end of each rotating rod is provided with a transmission gear set, the transmission gear set passes through the module slot and is connected to a drive motor, and the other end of each rotating rod is rotatably connected to the module slot.

[0009] As a preferred embodiment, the rotating rod has multiple mounting positions spaced axially along its shaft for mounting neodymium magnet assemblies, the neodymium magnet assemblies comprising a pair of neodymium magnets with opposite magnetic polarities and symmetrically arranged radially along the rotating rod.

[0010] As a preferred embodiment, the rotation axis of the neodymium magnet assembly is perpendicular to the plane of the frame, so that when the neodymium magnet assembly rotates with the rotating rod, its magnetic poles alternately face towards and away from the surface of the multilayer corrugated metal diaphragm assembly, thereby generating an alternating magnetic field with periodically changing direction inside the multilayer corrugated metal diaphragm assembly.

[0011] As a preferred embodiment, the magnetic particles can be driven by the alternating magnetic field generated by the neodymium magnet assembly to oscillate and rotate in the low-boiling-point dielectric liquid. The movement disturbs the flow of the low-boiling-point dielectric liquid in the boundary layer of the evaporation section, promotes the generation and detachment of bubbles, and enhances the boiling heat transfer coefficient.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention replaces the rigid sealing structure of the traditional explosion-proof enclosure with a multi-layer corrugated metal diaphragm assembly. It utilizes the elastic compression of the corrugations to absorb the energy of the explosion impact, and uses the interlayer slits to achieve automatic flame quenching. At the same time, it utilizes the evaporation and condensation cycle of the phase change working fluid to achieve efficient heat conduction. This solves the technical problem that the heat dissipation capacity of existing explosion-proof switchgear is severely limited due to its reliance on the solid heat conduction of the metal enclosure. Under the premise of meeting the explosion-proof requirements, the heat dissipation power is increased several times, and the temperature rise of the internal components of the drawer unit is effectively reduced.

[0013] 2. This invention, by mixing magnetic particles into a liquid phase change working fluid, and with the help of an auxiliary heat transfer component, can utilize the oscillating motion of the magnetic particles to disturb the boundary layer of the evaporation section, promote bubble generation and detachment, and enhance the nucleation boiling heat transfer coefficient.

[0014] 3. By integrating the heat dissipation unit into the installation opening of the drawer unit, the heat dissipation unit is thin and light, and does not occupy the installation space inside the drawer unit. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the external structure of a modular low-voltage switchgear suitable for smart grids proposed in this invention. Figure 2 This is a cross-sectional view of the internal structure of a modular low-voltage switchgear suitable for smart grids proposed in this invention. Figure 3 This is a schematic diagram of the module slot structure in a modular low-voltage switchgear suitable for smart grids proposed in this invention; Figure 4 This is a schematic diagram of the structure of an auxiliary heat transfer component in a modular low-voltage switchgear suitable for smart grids, as proposed in this invention. Figure 5 This is a schematic diagram of the external structure of a drawer unit in a modular low-voltage switchgear suitable for smart grids, as proposed in this invention. Figure 6 This is a structural assembly diagram of a drawer unit in a modular low-voltage switchgear suitable for smart grids, as proposed in this invention. Figure 7 This is a schematic diagram of the structure of a breathing heat dissipation unit in a modular low-voltage switchgear suitable for smart grids, as proposed in this invention. Figure 8 This is a structural assembly diagram of a metal foil and perforated spacer layer in a modular low-voltage switchgear suitable for smart grids, as proposed in this invention.

[0016] In the diagram: 1. Cabinet; 2. Module slot; 3. Main shell; 4. Cover plate; 5. Components; 6. Mounting port; 7. Frame; 8. Rectangular slot; 9. Rotating rod; 10. Neodymium magnet assembly; 11. Metal foil; 12. Small hole spacer layer; 13. Transmission gear set; 14. Drive motor; 15. Mounting position. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0018] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0019] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0020] Example, refer to Figures 1 to 8 A modular low-voltage switchgear suitable for smart grids includes a cabinet 1, a plurality of module slots 2 inside the cabinet 1, a plurality of auxiliary heat transfer components inside the module slots 2, a drawer unit installed inside the module slots 2, the drawer unit includes a main shell 3, a cover plate 4 on the top of the main shell 3, components 5 inside the main shell 3, and a plurality of rectangular mounting openings 6 on both sides of the main shell 3 and the top of the cover plate 4, with a breathing heat dissipation unit inside the mounting openings 6; The breathing heat dissipation unit includes a frame 7, which contains a multi-layer corrugated metal diaphragm assembly. The corrugated metal diaphragm assembly is filled with a liquid phase change working fluid, which is composed of a mixture of a low-boiling-point dielectric liquid and magnetic particles. The auxiliary heat transfer assembly includes multiple sets of paired rotating rods 9 and rectangular slots 8 opened in the module slots 2. The shape and position of the rectangular slots 8 match the frame 7. Neodymium magnets 10 are provided on the rod body of the rotating rods 9.

[0021] Furthermore, the multilayer corrugated metal diaphragm assembly is composed of multiple metal foils 11. A perforated spacer layer 12 is provided between two adjacent metal foils 11 to maintain the interlayer gap and prevent adjacent metal foils 11 from sticking together under pressure. The edges of each metal foil 11 are sealed to the inner peripheral wall of the frame 7 by welding. The surface of the metal foil 11 is pressed with a periodically distributed corrugated structure. It should be noted that the metal foil 11 is made of weakly magnetic stainless steel foil to reduce the eddy current shielding effect and ensure that the alternating magnetic field can effectively penetrate the cavity.

[0022] The further advantage of adopting the above is that when a high-voltage shock wave is generated inside the drawer unit due to an arc fault, the outer metal foil 11 absorbs most of the impact energy through the elastic compression of the corrugations. Even if the outer layer undergoes plastic deformation or even micro-cracks, the inner metal foil 11 can still maintain a complete airtight state due to the buffer protection of the outer layer and the spacer layer. This ensures that the breathing heat dissipation unit still has basic heat dissipation function after an explosion accident. Through the narrow gaps between each metal foil 11 and the perforated spacer layer 12, when the internal flame attempts to spread outward through the cracks in the outer layer, it must pass through these narrow channels. The flame temperature drops sharply in the slits because the heat is rapidly absorbed by the metal wall, eventually falling below the auto-ignition temperature of the combustible mixture, thus achieving automatic quenching. This can replace the passive protection method of the traditional explosion-proof enclosure that relies on a heavy shell and long flange gaps, reducing the overall weight of the drawer unit.

[0023] Furthermore, the trough areas of the corrugated structure facing the inside of the drawer unit form an evaporation heat absorption zone, and the crest areas of the corrugated structure facing the outside of the drawer unit form a condensation heat release zone. The corrugated structure inside the multi-layer corrugated metal diaphragm assembly is arranged in parallel along the surface of the metal foil 11, so that the grooves between adjacent corrugations form a capillary reflux channel. The equivalent hydraulic diameter of the capillary reflux channel is set to be able to use surface tension to drive the condensed liquid phase change working fluid to reflux from the condensation section to the evaporation section, thereby realizing the circulation of the liquid phase change working fluid without external power. It should be noted that: the liquid phase change working fluid is filled in the closed cavity of the multilayer corrugated metal diaphragm assembly. When the component 5 inside the drawer unit is energized and heats up, the heat is transferred to the trough area (evaporation heat absorption area) of the diaphragm assembly through air convection and solid heat conduction. Because the temperature of the trough wall is higher than the saturation temperature of the working fluid under the current cavity pressure, the liquid working fluid begins nucleation boiling in the microscopic pits on the trough wall, generating a large number of tiny bubbles. Each bubble continuously absorbs latent heat of vaporization during its formation and growth, transferring heat from the wall to the vapor inside the bubble. When the bubble grows to a critical size, it detaches from the wall under the combined action of buoyancy, capillary force, and the oscillation disturbance of magnetic particles, entering the bulk of the working fluid. Vapor carrying latent heat diffuses within the cavity towards the cooler crest region (condensation and heat release zone). The crest wall, being close to the external environment of cabinet 1, has a lower temperature. Upon contact with the cold wall surface, the vapor condenses, releasing latent heat. This heat is conducted through the metal foil 11 to the outer surface of the diaphragm and dissipates into the environment. The condensed liquid working fluid, driven by the capillary force of the corrugated grooves, automatically returns to the trough region along the capillary reflux channel, replenishing the liquid consumed by evaporation and completing a full phase change cycle of evaporation, transport, condensation, and reflux. This is the principle of boiling heat dissipation, which will not be elaborated further below.

[0024] The further advantage of the above-mentioned approach is that, in the multi-layer corrugated metal diaphragm assembly, each layer of metal foil 11 independently absorbs heat and evaporates through the troughs (towards the inside of the drawer) and releases heat and condenses through the peaks (towards the outside of the drawer), forming a single-layer thermal diode effect. When multiple layers are stacked, heat is transferred sequentially from the troughs of the innermost layer to the peaks of that layer, and then becomes the heat source of the adjacent outer layer troughs through interlayer solid heat conduction and radiation. At this time, the interlayer is separated by a perforated spacer layer 12 to form a heat-insulating buffer air gap, avoiding direct solid heat conduction between layers and ensuring independent phase change heat transfer of each layer. This relay transfer occurs layer by layer, and finally the outermost peak dissipates the heat to the external environment. Each layer of metal foil 11 only needs to bear a small part of the total temperature difference to maintain an efficient phase change cycle, which reduces the dependence of a single layer on temperature difference, avoids local drying, and achieves a larger total heat transfer flux through multi-level thermal resistance distribution. Thus, without relying on external power, the heat inside the drawer is stably and directionally pumped to the outside of the cabinet 1.

[0025] Furthermore, the two rotating rods 9 are arranged in parallel, and one end of the two rotating rods 9 is provided with a transmission gear set 13. The transmission gear set 13 passes through the module slot 2 and is connected to the drive motor 14. The other end of the two rotating rods 9 is rotatably connected to the module slot 2. Furthermore, a plurality of mounting positions 15 are provided axially spaced on the shaft of the rotating rod 9 for mounting neodymium magnet assembly 10. The neodymium magnet assembly 10 includes a pair of neodymium magnets with opposite magnetic polarities and arranged radially symmetrically along the rotating rod 9. Furthermore, the rotation axis of the neodymium magnet assembly 10 is perpendicular to the plane where the frame 7 is located, so that when the neodymium magnet assembly 10 rotates with the rotating rod 9, its magnetic poles alternately face towards and away from the surface of the multilayer corrugated metal diaphragm assembly, thereby generating an alternating magnetic field with periodically changing direction inside the multilayer corrugated metal diaphragm assembly. The frequency of the alternating magnetic field changes with the rotation speed of the rotating rod 9 and can be adjusted within a certain range to generate a magnetic field of sufficient strength at the surface of the corrugated metal diaphragm assembly to drive the magnetic particles. The further advantage of the above is that the multiple mounting positions 15 spaced along the axial direction on the rotating rod 9 allow each neodymium magnet group 10 to cover a local area of ​​the frame 7. The multiple mounting positions 15 are connected in series to form a complete coverage of the entire rectangular groove 8 along its length, avoiding magnetic field blind spots. When the radially symmetrical pair of neodymium magnets rotate, they generate a periodic flipping magnetic field, driving the magnetic particles to oscillate back and forth in the liquid working fluid, thus achieving the boundary layer disturbance effect.

[0026] Furthermore, the magnetic particles can be driven by the alternating magnetic field generated by the neodymium magnet assembly 10 to oscillate and rotate in the low-boiling-point dielectric liquid. The movement disturbs the flow of the low-boiling-point dielectric liquid in the boundary layer of the evaporation section, promotes the generation and detachment of bubbles, and enhances the boiling heat transfer coefficient. It should be noted that low-boiling-point dielectric liquid is an existing technology, and its boiling point is much lower than that of water. Depending on the specific working conditions, a low-boiling-point dielectric insulating liquid with a boiling point range of 30℃ to 80℃ can be selected. At the same time, low-boiling-point dielectric liquid has extremely high volume resistivity, and even if it comes into direct contact with live parts in its liquid state, it will not cause short circuits or leakage. This characteristic provides a fundamental guarantee for the safe application of breathing heat dissipation units inside electrical equipment. Even if a small amount of working fluid leaks due to long-term operation or mechanical damage, it will not cause secondary electrical faults.

[0027] The further advantage of adopting the above is that the breathing heat dissipation unit has a thin and light structure, does not occupy the internal space of the drawer unit, and solves the problem of volume expansion caused by increasing the wall thickness or adding heat sinks to improve heat dissipation in traditional explosion-proof housings.

[0028] When this invention is in use, heat first accumulates in the air inside the main housing 3, causing the temperature of the innermost metal foil 11 of the multi-layer corrugated metal diaphragm assembly to rise rapidly. When the temperature of the trough wall of the metal foil 11 exceeds the saturation temperature of the liquid phase change working fluid under the current cavity pressure, the liquid phase change working fluid begins to boil. The troughs of each layer of metal foil 11 face inward and simultaneously carry out an evaporation and heat absorption process, forming a parallel heat absorption. The generated vapor migrates to the crest region within its respective layer under the drive of a small pressure difference and condenses and releases heat at the crest. The condensed liquid working fluid automatically refluxes in the capillary reflux channels of each layer, maintaining continuous circulation.

[0029] At the same time, the drive motor 14 installed outside the module slot 2 starts, and the motor drives the two parallel rotating rods 9 and the neodymium magnets on the rotating rods 9 to rotate synchronously through the transmission gear set 13, generating a periodically flipping alternating magnetic field in the rectangular slot 8. The magnetic field penetrates the frame 7 and the multi-layer corrugated metal diaphragm assembly, driving the magnetic particles suspended in the low-boiling-point dielectric liquid to reciprocate and rotate at high speed. The mechanical movement of the magnetic particles continuously scours the thermal boundary layer at the trough walls, causing bubbles attached to the walls to detach prematurely and exposing new vaporization nuclei, thus significantly increasing the number of bubbles generated per unit time. As the heat generated by component 5 changes, the control system can adjust the motor speed in real time: increasing the speed to enhance stirring when the heat generation is high, and decreasing the speed to reduce energy consumption and noise when the heat generation is low, achieving on-demand energy supply.

[0030] If an arcing fault occurs inside the drawer unit due to insulation failure, poor contact, or overvoltage, the instantaneously generated high-temperature and high-pressure shock wave will first act on the outermost layer of the multi-layer corrugated metal diaphragm assembly. The corrugated structure of the outer metal foil 11 will undergo elastic compression or even plastic deformation under pressure, absorbing most of the impact energy. At the same time, the narrow gaps between the layers will cause the flame attempting to spread outward to be automatically quenched as the heat is rapidly absorbed by the metal wall when it passes through, preventing the flame from leaking out. During this process, even if the outer layer develops micro-cracks or permanent deformation in the explosion, the inner metal foil 11 can still maintain an intact airtight state due to the buffer protection of the outer layer and the spacer layer, preventing the damage from spreading.

[0031] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A modular low-voltage switchgear suitable for smart grids, comprising a cabinet (1), characterized in that, The cabinet (1) is provided with multiple module slots (2), and the module slots (2) are provided with multiple auxiliary heat transfer components. The module slots (2) are installed with drawer units. The drawer units include a main shell (3). The top of the main shell (3) is provided with a cover plate (4). The inside of the main shell (3) is provided with components (5). The sides of the main shell (3) and the top of the cover plate (4) are provided with multiple rectangular mounting holes (6). The mounting holes (6) are provided with breathing heat dissipation units. The breathing heat dissipation unit includes a frame (7), and the frame (7) is provided with a multi-layer corrugated metal diaphragm group. The corrugated metal diaphragm group is filled with a liquid phase change working fluid, which is composed of a mixture of low-boiling-point dielectric liquid and magnetic particles. The auxiliary heat transfer component includes multiple sets of paired rotating rods (9) and multiple rectangular slots (8) opened in the module slots (2). The shape and position of the rectangular slots (8) match the frame (7). The rotating rods (9) are provided with neodymium magnet groups (10).

2. The modular low-voltage switchgear suitable for smart grids according to claim 1, characterized in that, The multilayer corrugated metal diaphragm assembly is composed of multiple metal foils (11), with a perforated spacer layer (12) between two adjacent metal foils (11) to maintain the interlayer gap. The edges of each metal foil (11) are sealed to the inner peripheral wall of the frame (7) by welding. The surface of the metal foil (11) is pressed with a periodically distributed corrugated structure.

3. A modular low-voltage switchgear suitable for smart grids according to claim 2, characterized in that, The trough area of ​​the corrugated structure faces the inside of the drawer unit to form an evaporation heat absorption zone, and the peak area of ​​the corrugated structure faces the outside of the drawer unit to form a condensation heat release zone. The corrugated structure inside the multi-layer corrugated metal diaphragm group is arranged in parallel along the surface of the metal foil (11), so that the grooves between adjacent corrugations form a capillary reflux channel.

4. A modular low-voltage switchgear suitable for smart grids according to claim 3, characterized in that, The equivalent hydraulic diameter of the capillary reflux channel can utilize surface tension to drive the condensed liquid phase change working fluid to reflux from the condensation section to the evaporation section, achieving working fluid circulation without external power.

5. A modular low-voltage switchgear suitable for smart grids according to claim 1, characterized in that, The two rotating rods (9) are arranged in parallel. One end of the two rotating rods (9) is provided with a transmission gear set (13). The transmission gear set (13) passes through the module slot (2) and is connected to a drive motor (14). The other end of the two rotating rods (9) is rotatably connected to the module slot (2).

6. A modular low-voltage switchgear suitable for smart grids according to claim 5, characterized in that, The rotating rod (9) has multiple mounting positions (15) spaced axially along its shaft for mounting neodymium magnet assembly (10). The neodymium magnet assembly (10) includes a pair of neodymium magnets with opposite magnetic polarities and arranged radially symmetrically along the rotating rod (9).

7. A modular low-voltage switchgear suitable for smart grids according to claim 6, characterized in that, The rotation axis of the neodymium magnet assembly (10) is perpendicular to the plane of the frame (7), so that when the neodymium magnet assembly (10) rotates with the rotating rod (9), its magnetic pole direction alternately faces and moves away from the surface of the multilayer corrugated metal diaphragm assembly, thereby generating an alternating magnetic field with periodically changing direction inside the multilayer corrugated metal diaphragm assembly.

8. A modular low-voltage switchgear suitable for smart grids according to claim 3, characterized in that, The magnetic particles can be driven by the alternating magnetic field generated by the neodymium magnet group (10) to oscillate and rotate in the low-boiling-point dielectric liquid. The movement disturbs the flow of the low-boiling-point dielectric liquid in the boundary layer of the evaporation section, promotes the generation and detachment of bubbles, and enhances the boiling heat transfer coefficient.

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