Magnetofluid type silicon controlled rectifier radiator and heat dissipation control method thereof

Abstract

The invention discloses a magnetofluid type silicon controlled rectifier radiator and a heat dissipation control method thereof. The radiator comprises a silicon controlled rectifier, a magnetic fluid chamber is attached to the outer side of the silicon controlled rectifier, the magnetic pole array is installed in the magnetic fluid chamber, and cooling fins are assembled outside the magnetic fluid chamber. When alternating current is introduced into the cavity where the magnetic fluid liquid chamber is located, the alternating current and the magnetic field interact to generate Lorentz force, the Lorentz force drives the magnetic fluid to form directional eddy current so as to achieve convective heat exchange on the silicon controlled rectifier, and heat absorbed by the magnetic fluid and air are subjected to heat exchange through the cooling fins. Junction temperature out-of-control caused by local hot spots of the silicon controlled rectifier can be solved, secondary damage of mechanical vibration of a heat dissipation system to welding spots is eliminated, and the highest junction temperature area of the silicon controlled rectifier is focused and cooled according to needs.

Description

TECHNICAL FIELD

[0001] The application relates to a magnetic fluid type silicon controlled rectifier radiator and a radiator heat dissipation control method thereof, and belongs to the technical field of radiators. BACKGROUND

[0002] In the field of power electronic device heat dissipation technology, as the core component of high-power industrial equipment such as servo drivers and frequency converters, silicon controlled rectifiers generate a large amount of heat during operation. If the heat cannot be dissipated in time, the junction temperature will rise and even be out of control, which seriously affects the stability and service life of the equipment. Therefore, an efficient heat dissipation scheme is crucial for the reliable operation of silicon controlled rectifiers and the entire industrial equipment.

[0003] Currently, three types of technical solutions are mainly used for the heat dissipation of silicon controlled rectifiers. The first type is an air-cooled radiator composed of heat dissipation fins and an axial flow fan. The fan drives air flow to accelerate the heat exchange between the heat dissipation fins and the air to achieve cooling. However, this type of solution has obvious defects. The mechanical vibration generated by the operation of the axial flow fan continuously acts on the connection welds of the silicon controlled rectifier and the radiator, accelerating the fatigue damage of the welds and shortening the service life of the components. At the same time, the heat exchange capacity of the air-cooled method is limited and cannot cope with the large range of heat flux density changes during the operation of the silicon controlled rectifier. In high load conditions, the problem of delayed heat dissipation easily occurs. The second type is a liquid-cooled radiator, which includes a water-cooled plate, a mechanical pump and a circulation pipeline. The mechanical pump drives the cooling liquid to circulate in the pipeline and the water-cooled plate, absorbs the heat generated by the silicon controlled rectifier, and then exports it through a heat exchange component. However, the liquid cooling solution has a high risk of leakage. Once the cooling liquid leaks, it may cause safety accidents such as equipment short circuit. In addition, the operation of the mechanical pump consumes additional energy, which accounts for a considerable proportion of the total system power consumption, which is not conducive to the improvement of the overall energy efficiency of the equipment. The third type is a traditional magnetic fluid radiator, which mainly consists of a permanent magnet and a magnetic fluid chamber. The static magnetic field generated by the permanent magnet drives the magnetic fluid in the chamber to flow, achieving heat exchange with the silicon controlled rectifier. However, the traditional magnetic fluid radiator has a key technical bottleneck. The magnetic particles in the magnetic fluid are prone to sedimentation under the long-term action of the static magnetic field, causing the heat conduction and flow performance of the magnetic fluid to gradually degrade, and the heat dissipation efficiency to continuously decline. At the same time, the distribution of the static magnetic field is fixed and cannot be dynamically adjusted according to the position of the millimeter-level junction area hot spot on the surface of the silicon controlled rectifier, making it difficult to achieve precise cooling of the hot spot area and unable to meet the demand for rapid cooling of local high-temperature areas of the silicon controlled rectifier.

[0004] In summary, the three existing controllable silicon heat dissipation schemes all have their own technical shortcomings, and cannot simultaneously meet the three core requirements of no mechanical vibration, high insulation safety, and precise cooling of hot spots. After in-depth analysis of the root causes, both the air-cooled and liquid-cooled schemes rely on mechanical moving parts, and the operation of the fan and mechanical pump is inevitably accompanied by vibration and additional energy consumption, and the pipe connection structure of the liquid-cooled scheme is difficult to completely avoid the risk of leakage; and the traditional magnetic fluid radiator uses a fixed static magnetic field to drive, lacks dynamic magnetic field regulation and control capability, and cannot solve the problem of magnetic particle sedimentation, nor can it achieve directional cooling of local hot spots. These technical defects make it difficult for existing schemes to adapt to the high-performance requirements of large-power industrial equipment for controllable silicon heat dissipation, and a new heat dissipation technology scheme is urgently needed to break through the current bottleneck. SUMMARY

[0005] The present application aims to: In view of the above problems, a magnetic fluid type controllable silicon heat sink and its heat dissipation control method are provided, which can solve the problem of uncontrollable junction temperature caused by local hot spots of controllable silicon, eliminate the secondary damage of mechanical vibration of the heat dissipation system to the welding point, and realize on-demand focused cooling of the highest junction temperature area of controllable silicon.

[0006] The technical scheme adopted by the present application is as follows: A magnetic fluid type controllable silicon heat sink, comprising a controllable silicon, a magnetic fluid liquid chamber is attached to the outside of the controllable silicon, a magnetic pole array is installed in the magnetic fluid liquid chamber, and a heat sink is assembled outside the magnetic fluid liquid chamber; when an alternating current is passed through the cavity where the magnetic fluid liquid chamber is located, the alternating current interacts with the magnetic field to generate a Lorentz force, which drives the magnetic fluid to form a directional eddy current to realize convective heat transfer of the controllable silicon, and the heat sink completes heat exchange with air.

[0007] Alternatively, the magnetic fluid in the magnetic fluid liquid chamber is composed of a glycol-based carrier liquid and Fe3O4 magnetic particles, the Fe3O4 magnetic particles are uniformly dispersed in the glycol-based carrier liquid to form a stable suspension system.

[0008] Alternatively, the Fe3O4 magnetic particles are nano-sized particles, and the particle surface is coated with a surfactant; the surfactant is oleic acid, which is used to offset the van der Waals force and magnetic attraction between Fe3O4 particles, prevent particle agglomeration, and improve the dispersion stability of the particles in the glycol-based carrier liquid.

[0009] Alternatively, the magnetic pole array includes a middle magnetic pole array and two side magnetic pole arrays on both sides; wherein the magnetic pole arrays are alternately and symmetrically distributed, respectively installed on the opposite sides of the magnetic fluid liquid chamber, and each magnetic pole array cooperates to form a orthogonal magnetic field in the liquid chamber.

[0010] Alternatively, the magnetic fluid chamber comprises an outer shell and an inner fluid containing space; the outer shell is made of aluminum or copper material, has corrosion resistance and predetermined structural strength; the inner fluid containing space and the magnetic pole array maintain a predetermined distance to ensure that the magnetic field can fully penetrate into the magnetic fluid, and the inner fluid containing space has a smooth inner wall to reduce the flow resistance of the magnetic fluid.

[0011] Alternatively, the magnetic fluid chamber is a double-cavity isolation structure, and the heat source and the bottom and top surfaces of the silicon controlled rectifier body are respectively attached to two magnetic fluid chambers.

[0012] Alternatively, the heat sink is made of high thermal conductivity metal material and has a multi-piece sheet structure to expand the heat dissipation area; the heat sink is fixed to the upper surface of the magnetic fluid chamber, and the contact surface of the heat sink and the liquid chamber is coated with thermal conductive silicone grease to improve the heat transfer efficiency.

[0013] Alternatively, it also includes a current frequency control module; the current frequency control module is electrically connected with the cavity power supply circuit, can adjust the frequency of the alternating current according to the junction temperature detection data of the silicon controlled rectifier, makes the eddy current accurately focus on the area with the highest junction temperature of the silicon controlled rectifier, and realizes directional cooling of the hot spot.

[0014] A heat dissipation control method of a magnetic fluid type silicon controlled rectifier heat sink, characterized in that it comprises the following steps: Step 1, constructing a heat sink main structure comprising a silicon controlled rectifier, a magnetic fluid chamber, a magnetic pole array and a heat sink, so that the silicon controlled rectifier is attached to the magnetic fluid chamber to realize heat transfer; Step 2, filling the magnetic fluid chamber with magnetic fluid of a predetermined composition to ensure that the magnetic fluid fills the inner fluid containing space of the liquid chamber; Step 3, installing the magnetic pole array at a predetermined position of the magnetic fluid chamber to make each magnetic pole work together to form a specific magnetic field in the liquid chamber; Step 4, passing an alternating current into the conductive cavity where the magnetic fluid chamber is located, so that the alternating current interacts with the magnetic field formed in step 3 to generate Lorentz force; Step 5, driving the magnetic fluid to form a macroscopic directional eddy current in the liquid chamber by the Lorentz force, using the eddy current to vertically flush the surface of the silicon controlled rectifier, converting the laminar boundary layer into turbulent flow to realize convective heat transfer; Step 6, through the heat sink assembled outside the magnetic fluid chamber, the heat absorbed by the magnetic fluid from the silicon controlled rectifier is exchanged with the air to complete heat dissipation.

[0015] Alternatively, step 4 further comprises detecting the junction temperature distribution of the silicon controlled rectifier in real time by a temperature sensor to determine the position and temperature value of the area with the highest junction temperature; adjusting the frequency of the alternating current passed into the cavity according to the detection data to make the eddy current formed in step 5 accurately focus on the area with the highest junction temperature of the silicon controlled rectifier, and realize directional cooling of the hot spot.

[0016] To sum up, due to the adoption of the technical scheme, the application has the beneficial effects: 1、The magnetic fluid type thyristor radiator and the heat dissipation control method thereof provided by the application use Lorentz force driving to replace fan driving, which not only eliminates vibration hazards, but also solves the problem of narrow heat flux density adaptation range through eddy current enhanced heat exchange; without complex circulating pipelines and mechanical pumps, the structure is simplified, the leakage probability is greatly reduced, no additional driving energy consumption is needed, the system safety and energy efficiency are improved; the directional eddy current of Lorentz force driving can avoid the sedimentation of particles due to the action of the static magnetic field, and the directionality of the eddy current can focus the heating area of the thyristor, solving the defect that the traditional scheme cannot accurately cool the millimeter-level junction area hot spot, and realizing multi-dimensional optimization and breakthrough of the existing thyristor heat dissipation technology.

[0017] 2、The magnetic fluid type thyristor radiator and the heat dissipation control method thereof provided by the application, the magnetic fluid adopts a composite formula of ethylene glycol-based carrier liquid and nano Fe3O4 particles, and a stable suspension system constructed with oleic acid surfactant, forming an efficient heat conduction network to further accelerate heat transfer, which can easily cope with large-scale heat flux density changes of the thyristor and avoid local junction temperature out of control. It has precise and intelligent temperature control capability, relies on temperature sensors to detect the junction temperature distribution of the thyristor in real time, and dynamically adjusts the alternating current frequency in combination with the current frequency regulation module, so that the eddy current accurately focuses on the area with the highest junction temperature, realizing directional cooling of the hot spot. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a cross-sectional view of the magnetic fluid type thyristor radiator.

[0019] Figure 2 is a full view of the magnetic fluid type thyristor radiator.

[0020] Figure 3 is a top view of the magnetic fluid type thyristor radiator.

[0021] Figure 4 is a front view of the magnetic fluid type thyristor radiator located in the cabinet Markings in the figure: 1 - heat dissipation fin, 2 - thyristor, 3 - middle magnetic pole array, 4 - internal fluid containing space, 5 - side magnetic pole array, 6 - external shell. DETAILED DESCRIPTION

[0022] The application will be described in detail below with reference to the drawings.

[0023] In order to make the purpose, technical scheme and advantages of the application clearer and more apparent, the application will be further described in detail below with reference to the drawings and examples. It should be understood that the specific examples described herein are only used to explain the application and not to limit the application.

[0024] A magnetic fluid type silicon controlled rectifier heat sink, as shown in Figures 1-4 includes a silicon controlled rectifier 2, the outer side of which is attached with a magnetic fluid liquid chamber, the magnetic pole array is installed in the magnetic fluid liquid chamber, and the outer part of the magnetic fluid liquid chamber is equipped with a heat sink 1; when the cavity where the magnetic fluid liquid chamber is located is connected with an alternating current, the alternating current interacts with the magnetic field to generate a Lorentz force, which drives the magnetic fluid to form a directional vortex to realize convective heat exchange for the silicon controlled rectifier 2, and the heat sink 1 completes heat exchange between the heat absorbed by the magnetic fluid and the air.

[0025] The silicon controlled rectifier 2 is a core heating component of a high-power industrial equipment, and the magnetic fluid liquid chamber attached to the outer side has the dual functions of heat transfer and magnetic fluid bearing: on the one hand, by directly attaching to the silicon controlled rectifier 2, a high-efficiency heat conduction path between the heating component and the heat dissipation medium (magnetic fluid) is constructed, so as to ensure that the heat generated by the silicon controlled rectifier 2 can be quickly transferred to the magnetic fluid; on the other hand, a stable installation space is provided for the magnetic pole array, so as to guarantee the stable construction of the magnetic field environment. The magnetic pole array installed in the magnetic fluid liquid chamber is the core of the magnetic field generation, which forms a specific magnetic field through the magnetic pole distribution, provides the necessary magnetic field basis for the generation of the Lorentz force, and is the key prerequisite for realizing the driving of the magnetic fluid. The heat sink 1 equipped outside the magnetic fluid liquid chamber undertakes the final link of heat export, which expands the contact area with the air, efficiently dissipates the heat transferred by the magnetic fluid to the air, and completes the heat dissipation closed loop.

[0026] When the cavity where the magnetic fluid chamber is located is connected to an alternating current, the alternating current and the magnetic field formed by the magnetic pole array interact with each other, based on the Lorentz force principle in electromagnetism, generating a Lorentz force that can drive the movement of the magnetic fluid; the Lorentz force directly acts on the magnetic fluid, pushing the magnetic fluid to form a directional vortex flow in the liquid chamber, and the vortex flow continuously erodes the surface of the thyristor 2 in the movement process, breaking the laminar boundary layer existing in the traditional heat exchange process, and the turbulent effect brought by the vortex flow greatly improves the heat transfer rate between the thyristor 2 and the magnetic fluid, realizing efficient convective heat exchange; then, the magnetic fluid that has absorbed heat transfers the heat to the external heat sink 1 through the liquid chamber wall, and the heat sink 1 quickly transfers the heat to the air through natural convection or assisted convection, and finally completes the heat dissipation process of the thyristor 2. Compared with the existing thyristor 2 heat dissipation technology, it completely gets rid of the dependence on mechanical moving parts, and does not need the axial flow fan in the air cooling scheme or the mechanical pump in the liquid cooling scheme, which fundamentally eliminates the fatigue damage of the mechanical vibration to the connection welding point of the thyristor 2 and the heat sink, effectively prolongs the service life of the thyristor 2 and the whole heat dissipation system, and avoids the additional energy consumption caused by the operation of mechanical parts. In addition, the turbulent heat exchange effect brought by the directional vortex flow significantly improves the heat exchange efficiency, which can easily cope with the large range of heat flux density changes of the thyristor 2 under different loads, and solves the problem of insufficient heat exchange capacity of the air cooling scheme. Moreover, the movement of the magnetic fluid driven by the Lorentz force has good stability, unlike the magnetic particle sedimentation problem caused by the dependence on the static magnetic field in the traditional magnetic fluid heat sink, the continuous movement of the directional vortex flow can effectively prevent the aggregation or sedimentation of the particles, guarantee the stability of the heat dissipation efficiency in the long-term use process, and avoid the defect of efficiency decay in the traditional magnetic fluid scheme.

[0027] In another specific implementation, the magnetic fluid within the magnetic fluid chamber is composed of an ethylene glycol-based carrier liquid and Fe3O4 magnetic particles. The Fe3O4 magnetic particles are uniformly dispersed in the ethylene glycol-based carrier liquid, forming a stable suspension system. The ethylene glycol-based carrier liquid, as the matrix of the magnetic fluid, firstly possesses excellent thermal conductivity, efficiently absorbing the heat transferred from the thyristor 2 to the chamber, providing a basic medium for heat diffusion within the magnetic fluid. Simultaneously, the ethylene glycol-based carrier liquid has a low freezing point and a high boiling point, adapting to a wide temperature range during industrial equipment operation, avoiding the impact of temperature fluctuations on heat dissipation stability due to phase changes in the carrier liquid. Furthermore, its chemically stable properties prevent reactions with components such as the chamber shell and magnetic pole array, ensuring the long-term reliability of the magnetic fluid. The Fe3O4 magnetic particles are the core of the magnetic fluid's response to the magnetic field. They possess strong magnetic permeability, enabling rapid magnetization within the magnetic field formed by the magnetic pole array. Driven by the Lorentz force under the coupling of alternating current and magnetic field, they become the driving force propelling the overall movement of the magnetic fluid, forming directional eddies. Furthermore, the thermal conductivity of Fe3O4 particles is higher than that of the ethylene glycol-based carrier liquid. After uniform dispersion, they can form a composite thermally conductive network combining the carrier liquid and the particles, further enhancing the overall thermal conductivity of the magnetofluid and strengthening the efficiency of heat transfer from the thyristor 2 to the magnetofluid. The uniform dispersion ensures that the Fe3O4 particles are evenly distributed within the liquid chamber, avoiding agglomeration due to excessively high local particle concentration or insufficient magnetic field response due to excessively low concentration. This allows the Lorentz force to act uniformly throughout the magnetofluid, driving the formation of stable and uniform directional eddies. This ensures that the eddies fully cover the surface of the thyristor 2, preventing localized weak heat transfer areas caused by uneven particle distribution.

[0028] In another specific embodiment, the Fe3O4 magnetic particles are nanoscale particles, and the particle surface is coated with a surfactant. The surfactant is oleic acid, which is used to counteract the van der Waals forces and magnetic attraction between Fe3O4 particles, prevent particle agglomeration, and improve the dispersion stability of the particles in the glycol-based carrier liquid. The nanoscale particle size gives the Fe3O4 particles a larger specific surface area, which on the one hand enhances the contact area between the particles and the glycol-based carrier liquid, improves the interfacial heat transfer efficiency between the two, and allows the heat absorbed by the particles to be transferred to the carrier liquid more quickly. On the other hand, the small-sized particles are more sensitive to the magnetic field and can more easily generate movement under the action of Lorentz force, reducing the overall flow resistance of the magnetofluid, making the formation of directional eddies smoother, and enhancing the scouring effect on the surface of the thyristor 2. Due to their extremely small size, the van der Waals forces between molecules and the magnetic attraction of the particles themselves are significantly enhanced, making them prone to agglomeration to form large particle clusters. Once clusters form, they will not only reduce the magnetic field response capability of the particles and hinder the formation of eddies, but also destroy the homogeneity of the magnetofluid, resulting in a decrease in local heat transfer efficiency. Oleic acid molecules form a coating layer on the particle surface, with their polar groups binding to the Fe3O4 particle surface and their non-polar groups facing the ethylene glycol-based carrier liquid. This creates steric hindrance and repulsion between the particles, effectively counteracting van der Waals forces and magnetic attraction, thus preventing particle aggregation at its source. This results in a more stable suspension system in the ethylene glycol-based carrier liquid, maintaining a uniform particle distribution even under long-term Lorentz force and temperature changes. This ensures the continuous and efficient action of directional eddy currents, thereby maintaining stable heat dissipation performance of the entire radiator and extending its maintenance cycle and service life.

[0029] In another specific implementation, the magnetic pole array comprises a central magnetic pole array 3 and two side magnetic pole arrays 5. The magnetic pole arrays are alternately and symmetrically distributed, installed on opposite sides of the magnetofluid chamber. Each magnetic pole array works together to form an orthogonal magnetic field within the chamber. The magnetic pole array consists of multiple magnetic poles arranged in an array, ensuring that the distance and angle between each pole meet design requirements. The central magnetic pole array 3 is located inside the magnetofluid chamber, while the side magnetic pole arrays 5 are opposite to the central array and attached to the outer side of the chamber. The S and N pole arrays are alternately arranged and parallel to each other. The central magnetic pole array can be a single row or a pair of oppositely arranged magnetic pole arrays. This combination of a central and side array layout, along with the alternating symmetrical distribution, constructs a highly efficient magnetic field system adapted to the space of the magnetofluid chamber. The central magnetic pole array 3 is located inside the liquid chamber and can directly release the magnetic field to the core area of ​​the magnetic fluid, reducing the energy loss of the magnetic field penetrating the liquid chamber wall and enhancing the magnetic field strength in the central area of ​​the magnetic fluid. The two side magnetic pole arrays 5 are attached to the outside of the liquid chamber and opposite to the central magnetic pole array 3. They can not only supplement the magnetic field to the edge area of ​​the liquid chamber, but also expand the magnetic field coverage through the synergistic effect with the central magnetic poles, ensuring that the magnetic fluid from the center to the edge of the liquid chamber can fully respond to the magnetic field.

[0030] In another specific embodiment, the magnetofluid chamber includes an outer shell 6 and an inner fluid-containing space 4. The outer shell 6 is made of aluminum or copper, possessing corrosion resistance and a predetermined structural strength. The inner fluid-containing space 4 maintains a predetermined distance from the magnetic pole array, ensuring that the magnetic field can fully penetrate into the magnetofluid. The inner fluid-containing space 4 also has a smooth inner wall to reduce the flow resistance of the magnetofluid. Aluminum and copper have good corrosion resistance, preventing chemical reactions when the magnetofluid is in long-term contact with the shell, and preventing structural damage caused by shell corrosion or impurities from entering the magnetofluid and affecting heat dissipation performance. On the other hand, the predetermined structural strength ensures the stability of the shell in the vibration environment of industrial equipment operation, while providing reliable installation support for external components such as the magnetic pole array and heat sink 1. The predetermined distance between the inner fluid-containing space 4 and the magnetic pole array allows the magnetic field to uniformly and fully cover the entire fluid-containing space, ensuring that particles throughout the magnetofluid are stably driven by the Lorentz force, guaranteeing the uniformity and intensity of the directional eddy current. The smooth inner wall can minimize the frictional resistance between the magnetofluid and the wall surface, allowing the eddy current to move more smoothly along the preset path. This ensures that the energy of the Lorentz force is used more to enhance heat transfer rather than overcome resistance, further improving the heat transfer efficiency and motion stability of the magnetofluid.

[0031] In another specific implementation, the magnetofluid chamber is a dual-chamber isolation structure, with the heat source and the bottom and top surfaces of the SCR2 column respectively in contact with the two magnetofluid chambers. Compared to single-chamber, single-sided heat dissipation, this not only increases the contact area for heat absorption but also avoids the uneven heat distribution that may result from single-sided heat dissipation. This makes it easier to maintain a balanced overall temperature for the SCR2, effectively alleviating the problem of excessively high local hot spot temperatures and further ensuring that the junction temperature of the SCR2 remains stable within a safe range.

[0032] In another specific implementation, the heat sink 1 is made of a high thermal conductivity metal and has a multi-plate structure to increase the heat dissipation area. The heat sink 1 is fixed to the upper surface of the magnetofluid liquid chamber, and thermal grease is applied to the contact surface between the heat sink 1 and the liquid chamber to improve heat transfer efficiency. The high thermal conductivity of the metal ensures that heat can be efficiently conducted inside the heat sink 1, avoiding local heat accumulation that would increase thermal resistance and laying the foundation for subsequent heat exchange with the air. The multi-plate structure significantly improves heat dissipation efficiency by increasing the contact area with the air. The layout of the heat sink 1 fixed to the upper surface of the magnetofluid liquid chamber forms a direct path for heat transfer. After the liquid chamber absorbs the heat from the thyristor 2 carried by the magnetofluid, it conducts the heat through the contact between the shell and the heat sink 1. This direct contact method reduces intermediate steps in heat transfer and avoids heat loss that may be caused by indirect conduction. The thermal grease, with its good thermal conductivity, allows heat to be transferred more smoothly from the liquid chamber shell to the heat sink 1, improving the overall heat transfer efficiency.

[0033] As another specific implementation, a current frequency control module is also included. This module is electrically connected to the cavity power supply circuit and can adjust the frequency of the alternating current based on the junction temperature detection data of the thyristor 2, allowing the eddy current to be precisely focused on the region with the highest junction temperature of the thyristor 2, achieving directional cooling of the hot spot. By matching the junction temperature data and the current frequency in real time, the current frequency control module maintains a dynamic balance between heat dissipation capacity and heat demand, avoiding energy waste and quickly responding to sudden hot spots when the load on the thyristor 2 fluctuates, strictly controlling the junction temperature within a safe threshold. Simultaneously, this control capability, combined with the dual-cavity isolation structure, also allows for independent adjustment of the eddy current intensity in the upper and lower cavities, further enhancing its adaptability to complex heating states of the thyristor 2.

[0034] A heat dissipation control method for a magnetic fluid type silicon controlled rectifier heat sink includes the following steps: Step 1: Construct the main structure of the heat sink, which includes the thyristor 2, the magnetofluid liquid chamber, the magnetic pole array and the heat sink 1, so that the thyristor 2 is in contact with the magnetofluid liquid chamber to achieve heat transfer; Step 2: Fill the magnetic fluid chamber with a preset composition of magnetic fluid to ensure that the magnetic fluid fills the fluid-containing space 4 inside the chamber; Step 3: Install the magnetic pole array at the preset positions in the magnetofluid chamber so that the magnetic poles work together to form a specific magnetic field in the chamber; Step 4: Introduce alternating current into the conductive cavity containing the magnetohydrodynamic chamber, so that the alternating current interacts with the magnetic field formed in Step 3 to generate Lorentz force. Step 5: Drive the magnetohydrodynamic fluid to form a macroscopic directional vortex in the liquid chamber through the Lorentz force. Use the vortex to vertically scour the surface of the thyristor 2 to convert the laminar boundary layer into turbulent flow to achieve convective heat transfer. Step 6: The heat absorbed by the thyristor 2 by the magnetic fluid is exchanged with the air through the heat sink 1 mounted on the outside of the magnetic fluid chamber, thus completing the heat removal.

[0035] Without relying on mechanical components, this method uses electromagnetically driven magnetofluid to form active convection, avoiding mechanical losses and vibrations while improving heat transfer efficiency through eddy current turbulence. The coordinated design of each step ensures that there are no significant bottlenecks in the entire process from heat generation to dissipation from the thyristor 2, allowing the heat dissipation capacity to dynamically adapt to the heating characteristics of the thyristor 2. Compared to existing heat dissipation control methods, this method achieves precise control of the magnetofluid's motion state through magnetic field construction in step 3 and alternating current regulation in step 4, enabling eddy currents to act directionally on the heating region. The turbulence enhancement mechanism in step 5 solves the problem of low heat transfer efficiency in traditional laminar flow.

[0036] As another specific implementation, step 4 further includes: using a temperature sensor to detect the junction temperature distribution of the thyristor 2 in real time, determining the location and temperature value of the region with the highest junction temperature; adjusting the frequency of the alternating current introduced into the cavity in step 4 based on the detection data, so that the eddy current formed in step 5 is precisely focused on the region with the highest junction temperature of the thyristor 2, achieving directional cooling of the hot spot. The temperature sensor captures the junction temperature distribution of the thyristor 2 in real time, which can not only locate the specific location of the region with the highest junction temperature, but also quantify its temperature value, breaking through the limitations of overall cooling in traditional heat dissipation, and providing precise target parameters for subsequent control. Adjusting the frequency of the alternating current based on the detection data, by changing the coupling characteristics of the current and magnetic field, achieves precise control of the direction and intensity of the Lorentz force. When the frequency is adapted to the hot spot location, the trajectory of the magnetohydrodynamic eddy current will focus towards that region, forming a stronger local turbulent scouring. This directional enhancement effect can quickly break the thermal boundary layer of the hot spot region, improving the heat transfer efficiency several times, and avoiding the problem of hot spot cooling lag caused by energy dispersion in traditional uniform heat dissipation.

[0037] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. The invention extends to any new features or combinations disclosed in this specification, and any modifications, equivalent substitutions, and improvements made within the spirit and principles of the invention should be included within the scope of protection of the invention. It is obvious to those skilled in the art that the invention is not limited to the details of the above exemplary embodiments, and that detailed technical features not disclosed in this embodiment, such as specific structures, are all prior art and can be obtained by those skilled in the art from the prior art. The connection method can be a fixed connection, a detachable connection, or an integral part; it can be a fixed connection, a movable connection, or a hinged connection; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific manner of the above terms in the embodiments of the present invention according to the specific circumstances, and this disclosure does not specifically limit this aspect.

Claims

1. A magnetohydrodynamic (MHD) thyristor heat sink, characterized in that: The system includes a thyristor (2), a magnetofluid chamber attached to the outside of the thyristor (2), a magnetic pole array installed inside the magnetofluid chamber, and a heat sink (1) assembled on the outside of the magnetofluid chamber. When an alternating current is passed through the cavity where the magnetofluid chamber is located, the alternating current interacts with the magnetic field to generate a Lorentz force. This Lorentz force drives the magnetofluid to form a directional eddy current to achieve convective heat transfer to the thyristor (2). The heat sink (1) completes the heat exchange between the magnetofluid and the air.

2. The magnetic fluid type thyristor heat sink according to claim 1, characterized in that, The magnetic fluid in the magnetic fluid chamber consists of an ethylene glycol-based carrier liquid and Fe3O4 magnetic particles. The Fe3O4 magnetic particles are uniformly dispersed in the ethylene glycol-based carrier liquid to form a stable suspension system.

3. The magnetohydrodynamic thyristor heat sink according to claim 2, characterized in that, The Fe3O4 magnetic particles are nano-sized particles, and the particle surface is coated with a surfactant. The surfactant is oleic acid, which is used to counteract the van der Waals forces and magnetic attraction between Fe3O4 particles, prevent particle agglomeration, and improve the dispersion stability of the particles in the ethylene glycol-based carrier liquid.

4. The magnetic fluid type thyristor heat sink according to claim 1, characterized in that, The magnetic pole array includes a central magnetic pole array (3) and side magnetic pole arrays (5) on both sides; wherein the magnetic pole arrays are alternately and symmetrically distributed and are installed on opposite sides of the magnetic fluid chamber, and each magnetic pole array works together to form an orthogonal magnetic field in the chamber.

5. The magnetic fluid type thyristor heat sink according to claim 1, characterized in that, The magnetic fluid chamber includes an outer shell (6) and an inner fluid containment space (4); the outer shell (6) is made of aluminum or copper and has corrosion resistance and a predetermined structural strength; the inner fluid containment space (4) maintains a predetermined distance from the magnetic pole array to ensure that the magnetic field can fully penetrate into the magnetic fluid, and the inner fluid containment space (4) has a smooth inner wall to reduce the flow resistance of the magnetic fluid.

6. The magnetic fluid type thyristor heat sink according to claim 1, characterized in that, The magnetofluid chamber is a dual-cavity isolation structure, with the bottom and top surfaces of the heat source and the thyristor (2) column respectively attached to the two magnetofluid chambers.

7. The magnetic fluid type thyristor heat sink according to claim 1, characterized in that, The heat sink (1) is made of a high thermal conductivity metal material and has a multi-plate structure to expand the heat dissipation area. The heat sink (1) is fixed on the upper surface of the magnetic fluid liquid chamber, and thermal grease is applied to the contact surface between the heat sink (1) and the liquid chamber to improve the heat transfer efficiency.

8. The magnetic fluid type thyristor heat sink according to claim 1, characterized in that, It also includes a current frequency control module; the current frequency control module is electrically connected to the cavity power supply circuit and can adjust the frequency of the alternating current according to the junction temperature detection data of the thyristor (2) so that the eddy current is accurately focused on the region with the highest junction temperature of the thyristor (2) to achieve directional cooling of hot spots.

9. A heat dissipation control method for a magnetic fluid type thyristor heat sink, characterized in that, Includes the following steps: Step 1: Construct a heat sink main structure including a thyristor (2), a magnetofluid chamber, a magnetic pole array and a heat sink (1), so that the thyristor (2) is attached to the magnetofluid chamber to achieve heat transfer; Step 2: Fill the magnetic fluid chamber with a preset composition of magnetic fluid to ensure that the magnetic fluid fills the fluid-containing space inside the chamber (4); Step 3: Install the magnetic pole array at the preset positions in the magnetofluid chamber so that the magnetic poles work together to form a specific magnetic field in the chamber; Step 4: Introduce alternating current into the conductive cavity containing the magnetohydrodynamic chamber, so that the alternating current interacts with the magnetic field formed in Step 3 to generate Lorentz force. Step 5: Drive the magnetohydrodynamic fluid to form a macroscopic directional vortex in the liquid chamber by the Lorentz force, and use the vortex to vertically scour the surface of the thyristor (2) to convert the laminar boundary layer into turbulent flow in order to achieve convective heat transfer. Step 6: The heat absorbed by the thyristor (2) by the magnetic fluid is exchanged with the air through the heat sink (1) assembled outside the magnetic fluid chamber, thus completing the heat removal.

10. The heat dissipation control method for a magnetic fluid type thyristor heat sink according to claim 1, characterized in that, Step 4 also includes: using a temperature sensor to detect the junction temperature distribution of the thyristor (2) in real time, determining the location and temperature value of the region with the highest junction temperature; adjusting the frequency of the alternating current introduced into the cavity in step 4 according to the detection data, so that the eddy current formed in step 5 is precisely focused on the region with the highest junction temperature of the thyristor (2), thereby achieving directional cooling of the hot spot.

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