A composite discrete fin motor heat dissipation system based on solid-solid phase change material

Abstract

The application discloses a composite discrete fin motor heat dissipation system based on solid-solid phase change material, and relates to the technical field of motor heat dissipation.The composite discrete fin motor heat dissipation system comprises a motor shell and a composite discrete fin, the composite discrete fin is sleeved on the outer wall of the motor shell and is equidistantly distributed, and the composite discrete fin is made of solid-solid phase change material; the solid-solid phase change material composite structure made of a metal matrix and phase change material is used as the composite discrete fin, heat shock can be relieved and heat dissipation capacity can be enhanced during motor operation, the solid-solid phase change material can absorb heat through phase change in a solid state, temperature change can be effectively adjusted when the motor load changes, the temperature rise of the motor stator and rotor can be effectively slowed down, the motor working efficiency is improved, damage caused by overheating is avoided, the service life of the motor is prolonged, the motor can be operated in an efficient and safe working temperature range, and the heat dissipation performance is better than that of traditional heat dissipation materials.

Description

Technical Field

[0001] This invention relates to the field of motor heat dissipation technology, and in particular to a composite discrete finned motor heat dissipation system based on solid-solid phase change materials. Background Technology

[0002] With the widespread application of electro-hydraulic energy systems and high-power motors, motors generate a large amount of heat under high load and long-term operation, causing the internal temperature of the motor to rise and seriously affecting its working efficiency and service life. Traditional motor cooling methods, such as air cooling and water cooling, can solve the heat dissipation problem to some extent, but in high-power motors, especially under overload operation and rapid load changes, they are often insufficient to meet the heat dissipation requirements.

[0003] In motor design, fins are typically used for heat dissipation, but traditional heat dissipation fins are mostly made of a single material, limiting their thermal conductivity and heat dissipation efficiency. To improve the heat dissipation capacity of motors, researchers have recently proposed using phase change materials (PCMs) to regulate temperature changes. PCMs can absorb a large amount of heat during phase change, thereby slowing down temperature rise. However, traditional PCMs are mostly solid-liquid phase change materials, which present flow problems and leakage risks in practical applications. Therefore, combining the advantages of PCMs with motor heat dissipation structures has become a significant technical challenge.

[0004] To address this issue, solid-solid phase change materials (SCTs), as a novel type of phase change material, have attracted widespread attention because they remain solid during the phase change process, avoiding the leakage problems associated with liquid phase change materials. SCTs undergo a phase change within a specific temperature range, enabling them to effectively absorb heat and regulate temperature fluctuations in high-temperature environments. Simultaneously, their high thermal conductivity effectively enhances heat dissipation capabilities.

[0005] However, there is limited research on the application of solid-solid phase change materials in motor heat dissipation fins in the prior art, and effective integration of solid-solid phase change materials and motor fins has not yet been achieved. Furthermore, there is a lack of optimized design for specific application scenarios. Therefore, this invention proposes a composite discrete fin motor heat dissipation system based on solid-solid phase change materials to solve the problems existing in the prior art. Summary of the Invention

[0006] To address the aforementioned problems, the present invention aims to propose a composite discrete finned motor heat dissipation system based on solid-solid phase change materials, which seeks to solve the problem of insufficient motor heat dissipation performance through the design and optimization of composite materials.

[0007] To achieve the objectives of this invention, the invention is implemented through the following technical solution: a composite discrete finned motor heat dissipation system based on solid-solid phase change material, comprising a motor housing and composite discrete fins, wherein the composite discrete fins are sleeved on the outer wall of the motor housing and are equidistantly distributed, the composite discrete fins are made of solid-solid phase change material, the solid-solid phase change material is composed of a metal matrix and a phase change material, the metal matrix is ​​a porous metal foam material, the phase change material is paraffin wax, and the paraffin wax, together with expanded graphite, is encapsulated inside the porous metal foam material by physical adsorption.

[0008] A further improvement lies in the following steps in the specific preparation method of the solid-solid phase change material:

[0009] A1. First, immerse the porous metal foam material in hydrochloric acid solution for pickling, then ultrasonically clean it with deionized water, and then dry it for later use.

[0010] A2. Heat solid paraffin wax until it is completely melted, then mix and stir the pre-prepared expanded graphite with paraffin wax according to the preset mass ratio to form a paraffin wax-expanded graphite mixture.

[0011] A3. The dried porous metal foam material is completely immersed in the paraffin-expanded graphite mixture. The pressure difference drives the mixture to penetrate into the pores of the porous metal foam material. After the pores are completely filled, the mixture is left to stand in a constant temperature environment to obtain a composite sample.

[0012] A4. After the composite sample is kept at a constant temperature, it is cooled and solidified. The paraffin wax shrinks in the pores of the porous metal foam material to form microencapsulated closed units, thus obtaining a solid-solid phase change material.

[0013] A further improvement is that the percentage concentration of the hydrochloric acid solution is 10%, and the mass ratio of the paraffin wax to the expanded graphite is 20:1 to 3.

[0014] A further improvement is that the porous metal foam material is prepared by powder metallurgy from metal alloy powder, Mn powder and B powder. The mixing mass ratio of the metal alloy powder, Mn powder and B powder is 94-96:3-4:1-2. The metal alloy powder is selected from either nickel-titanium alloy powder or copper-chromium-zirconium alloy powder. These materials have a low coefficient of thermal expansion and good high-temperature stability, and can maintain a stable structure over a wide temperature range.

[0015] A further improvement lies in the following: the method for preparing the porous metal foam material is as follows:

[0016] B1. Mix the metal alloy powder, Mn powder and B powder evenly according to the preset mass ratio to obtain a metal powder mixture;

[0017] B2. Mix the metal powder mixture with pre-weighed NaCl powder at a volume fraction of 40-70% to ensure uniform powder distribution and obtain a mixed powder.

[0018] B3. The prepared mixed powder is loaded into a mold and cold-pressed to form a green body;

[0019] B4. Place the cold-molded green body into distilled water for desalination treatment;

[0020] B5. The desalted green body is sintered under vacuum conditions, and after sintering, it is cooled to room temperature to produce a porous metal foam material.

[0021] A further improvement is that the pressure of cold molding after the mixed powder is loaded into the mold is set to 300-800 MPa, and the green body after cold molding is desalted in distilled water at 60-85°C for 1-3 days.

[0022] A further improvement is made in that: when the green body is sintered under vacuum conditions, it is first heated to 100-200°C at a rate of 5°C / min and held for 0.5-1h, then heated to 650-700°C at a rate of 5°C / min and held for 0.5-1h, then heated to 950-1100°C at a rate of 3°C / min and held for 0.5-5h, and finally cooled to room temperature at a rate of 7°C / min.

[0023] Further improvements include: a distribution plate and a swashplate assembly are fixed at both ends of the motor housing, the swashplate assembly is provided with a hydraulic oil inlet, the lower part of the motor housing near the swashplate assembly is provided with a hydraulic oil outlet, an oil chamber is provided inside the motor housing and filled with hydraulic oil, a motor rotor is rotatably connected inside the motor housing, a motor electromagnetic plate is fixed to the outer wall of the motor rotor, an electromagnetic copper strip is fixed to the outer wall of the motor electromagnetic plate, and a motor winding is connected to the inner wall of the motor housing through the motor stator.

[0024] The beneficial effects of the present invention are as follows: By adopting a composite structure of solid-solid phase change material and porous metal foam material, the present invention can effectively absorb and store excess heat when the motor is running under high load, reduce the drastic fluctuation of internal temperature of the motor, and thus significantly improve the heat dissipation efficiency of the motor.

[0025] The solid-solid phase change material used in this invention remains solid during the phase change process, avoiding the leakage problem that may occur in traditional solid-liquid phase change materials when the temperature changes, and ensuring the long-term stability and safety of the material.

[0026] The solid-solid phase change material used in this invention can regulate the absorption and release of heat within the phase change temperature range during motor operation, ensuring the temperature stability of the motor under high load and harsh operating conditions, thereby improving the reliability and service life of the motor.

[0027] The composite discrete fins of this invention are made of materials with high thermal conductivity and thermal management capabilities, which can effectively reduce the volume and weight of the motor cooling system while ensuring stronger heat dissipation capacity, making them suitable for the heat dissipation needs of high-power motors. Attached Figure Description

[0028] Figure 1 This is a three-dimensional structural schematic diagram of the composite discrete finned motor heat dissipation system based on solid-solid phase change material according to the present invention.

[0029] Figure 2 This is a cross-sectional view of the composite discrete finned motor heat dissipation system based on solid-solid phase change materials according to the present invention.

[0030] Figure 3 This is a schematic diagram of the composite discrete rib of the present invention;

[0031] Figure 4 This is a schematic diagram illustrating the stability and thermal decomposition characteristics test of the composite discrete ribs of the present invention.

[0032] Figure 5 These are scanning electron microscope (SEM) images of the porous metal foam material of the present invention;

[0033] Figure 6 This is a differential scanning calorimetry (DSC) analysis chart of the solid-solid phase change material of the present invention;

[0034] Figure 7 This is a schematic diagram showing the temperature comparison curves of different components of the present invention with and without solid-solid phase change material.

[0035] Figure 8 This is a temperature profile cloud diagram of the motor in the Y direction according to the present invention.

[0036] The components are: 1. Motor housing; 2. Composite discrete ribs; 3. Distribution plate; 4. Hydraulic oil inlet; 5. Hydraulic oil outlet; 6. Motor electromagnetic plate; 7. Motor rotor; 8. Swashplate assembly; 9. Electromagnetic copper bar; 10. Motor winding; 11. Oil chamber; 12. Motor stator. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] An electric motor is a device that converts electrical energy into mechanical energy. Its core principle is based on the law of electromagnetic induction and the action of Ampere's force. Torque is generated through the interaction of magnetic field and current, driving mechanical motion. Electric motors are the core power devices in modern industry and life, and their performance directly affects the efficiency and reliability of equipment.

[0039] Motor overheating refers to the phenomenon that the temperature of a motor rises during operation due to internal energy loss (such as resistance loss, core loss, mechanical friction, etc.). Reasonable temperature rise is normal, but abnormal overheating may lead to decreased efficiency, insulation aging, or even equipment damage.

[0040] Motor cooling involves actively or passively dissipating the heat generated during motor operation to maintain its temperature within a safe range, ensuring efficiency, lifespan, and reliability. Motor cooling solutions must be selected based on a comprehensive consideration of power rating, operating environment, and cost.

[0041] according to Figure 1 , Figure 2 , Figure 3 As shown, this embodiment provides a composite discrete finned motor heat dissipation system based on solid-solid phase change material, including a motor housing 1 as the motor shell and composite discrete fins 2 sleeved on the outer wall of the motor housing 1 and distributed at equal intervals. The composite discrete fins 2 adopt a discrete layout and dissipate heat from the external environment through thermal convection to optimize temperature regulation capability. A distribution plate 3 and a swash plate assembly 8 are fixed at both ends of the motor housing 1, respectively. The swash plate assembly 8 is provided with a hydraulic oil inlet 4. A hydraulic oil outlet 5 is provided at the lower part of the motor housing 1 near the swash plate assembly 8. An oil chamber 11 is provided inside the motor housing 1 and is filled with hydraulic oil. The hydraulic oil is used as a cooling medium. The flow of hydraulic oil and the composite discrete fins 2 work together to further improve heat dissipation performance. A motor rotor 7 is rotatably connected inside the motor housing 1. A motor electromagnetic plate 6 is fixed on the outer wall of the motor rotor 7. An electromagnetic copper strip 9 is fixed on the outer wall of the motor electromagnetic plate 6. A motor winding 10 is connected to the inner wall of the motor housing 1 through a motor stator 12.

[0042] The composite discrete fin 2 is made of solid-solid phase change material. Utilizing the phase change heat storage characteristics of solid-solid phase change material, it effectively alleviates thermal shock and enhances heat dissipation during motor operation. The solid-solid phase change material consists of a high thermal conductivity metal matrix and a phase change material with a low phase change temperature. It can alleviate thermal shock and enhance heat dissipation during motor operation. The metal matrix uses porous metal foam material to improve the overall thermal conductivity. The phase change material is paraffin wax, which has a high latent heat of phase change between 60℃ and 70℃. It can store a large amount of heat when the temperature reaches the phase change point, thereby effectively slowing down the temperature rise of the motor. Paraffin wax, together with expanded graphite that enhances thermal conductivity, is encapsulated inside the porous metal foam material through physical adsorption to enhance heat dissipation performance. This solid-solid phase change material absorbs heat through phase change in the solid state, and can effectively regulate temperature changes when the motor load changes, ensuring that the motor operates within a high-efficiency and safe operating temperature range.

[0043] The solid-solid phase change material in this embodiment is prepared according to the following steps:

[0044] A1. First, immerse the porous metal foam material in a 10% hydrochloric acid solution for 10 minutes to remove surface oxides. Then, ultrasonically clean it three times with deionized water. Finally, dry it in a 120℃ oven for 2 hours for later use. This completes the pretreatment of the porous metal foam material, ensuring that the surface of the porous metal foam material is clean and enhancing its capillary adsorption capacity.

[0045] A2. Heat solid paraffin wax to above 70°C to completely melt it. Add expanded graphite powder to the molten paraffin wax gradually at a mass ratio of paraffin wax to expanded graphite of 20:1 to 3 (10:1 in this example). First, mechanically stir at 800 rpm for 30 minutes to disperse it initially. Then, use ultrasonic treatment for 20 minutes to break up the agglomerates and form a uniform and stable paraffin wax-expanded graphite mixture. Maintain the temperature at 75 to 85°C throughout the process to prevent the paraffin wax from solidifying.

[0046] A3. The pretreated porous metal foam material is completely immersed in the paraffin-expanded graphite mixture, transferred to a vacuum chamber and evacuated to -0.1MPa. The pressure is maintained for 60 minutes to allow the air bubbles to be fully expelled. After the vacuum is slowly broken, the pressure difference is used to drive the mixture to penetrate into the pores of the porous metal foam material. This immersion-vacuuming process is repeated 3 times to ensure that the pores are completely filled. Finally, the mixture is kept at 80℃ for 2 hours to enhance the adsorption effect with the help of the capillary force of the metal pores, thus obtaining a composite sample.

[0047] A4. Finally, the composite sample, after being kept at a constant temperature, was cooled and solidified at 25°C for 4 hours. The paraffin wax shrank within the metal pores to form microencapsulated closed units, thus obtaining a solid-solid phase change material. After testing, its phase change temperature range was about 70°C, its phase change enthalpy was about 149 J / g, its thermal conductivity was 8.4 W / mK, its density was 6.5 g / cm3, and its specific heat capacity was 2300 J / gK.

[0048] The porous metal foam material of this embodiment is prepared by powder metallurgy using metal alloy powder, Mn powder and B powder. The mixing mass ratio of metal alloy powder, Mn powder and B powder is 94-96:3-4:1-2 (94:4:2 ratio is used in this embodiment). The metal alloy powder is selected from either nickel-titanium alloy powder or copper-chromium-zirconium alloy powder (nickel-titanium alloy powder is selected in this embodiment) to enhance thermal conductivity.

[0049] The porous metal foam material in this embodiment is prepared according to the following steps:

[0050] B1. Mix the metal alloy powder, Mn powder and B powder evenly in a mass ratio of 94:4:2 to obtain a metal powder mixture.

[0051] B2. Mix the prepared metal powder mixture with pre-weighed NaCl powder at a volume fraction of 40-70% (55% volume fraction in this example) to ensure uniform powder distribution and obtain a mixed powder.

[0052] B3. The prepared mixed powder is loaded into a mold and cold-pressed under a pressure of 300-800MPa to form a green body;

[0053] B4. Place the cold-molded green body into distilled water at a temperature of 60-85℃ for desalination treatment for 1-3 days (ensure that NaCl is completely removed).

[0054] B5. The desalted green body is sintered under vacuum conditions. First, the temperature is raised to 150℃ at a rate of 5℃ / min and held for 0.75h. Then, the temperature is raised to 675℃ at a rate of 5℃ / min and held for 0.8h. Next, the temperature is raised to 1000℃ at a rate of 3℃ / min and held for 3h. Finally, the temperature is lowered to room temperature at a rate of 7℃ / min to produce a porous metal foam material.

[0055] The porous metal foam material prepared by the above method has high porosity and good thermal conductivity, while ensuring the mechanical properties of the material, making it suitable for heat dissipation applications in high-temperature working environments.

[0056] Figure 4 This diagram illustrates the stability and thermal decomposition characteristics of composite discrete fins using testing methods such as X-ray diffraction and thermogravimetric analysis.

[0057] Figure 5 Scanning electron microscopy (SEM) images were used to visually demonstrate the pore distribution, morphology, and microstructure of the porous metal foam material (Ni-Mn-Ti-B).

[0058] Figure 6 The phase transition temperature range, latent heat of phase transition, and heat transfer characteristics of solid-solid phase change materials are characterized. The low-temperature phase change material (blue curve) has a phase transition range of 56.2–68.9℃, a peak temperature of 61.6℃, and a latent heat of phase transition of 142.7 J / g; the high-temperature phase change material (red curve) has a phase transition range of 70.6–82.2℃, a peak temperature of 79.6℃, and a latent heat of phase change of 149.4 J / g. The low-temperature material rapidly absorbs heat to suppress overheating, while the high-temperature material stably dissipates heat to adapt to high-load conditions. Compared to traditional solid-liquid phase change materials, it possesses higher thermal conductivity and long-term stability, and avoids the risk of leakage.

[0059] Figure 7 The curves illustrate the temperature evolution of the composite discrete fin 2 and hydraulic oil over time under different thermal management configurations. The system also compares the heat dissipation performance of fins without and with solid-solid phase change materials (SPCs). The results show that the composite discrete fin 2 enters the phase change region early in operation, significantly suppressing the temperature rise rate by absorbing latent heat and effectively reducing the overall system heat load. Compared with conventional metal fins, it exhibits superior thermal control performance in maintaining temperature stability, verifying the engineering feasibility and application value of SPCs in the thermal management of motors and hydraulic systems.

[0060] Figure 8 This shows the temperature profile contour plot of the motor in the Y direction. Figure 8 Part a in the diagram is a cross-sectional temperature contour map of the motor without phase change materials. Figure 8 Part b in the figure shows the temperature cloud map of the motor under the phase change material fins. It can be observed that, within a certain operating time, the composite discrete fins 2 made of solid-solid phase change material significantly reduced the overall temperature of the motor, demonstrating a good thermal control optimization effect.

[0061] In this embodiment, the phase change temperature range of the solid-solid phase change material is set to 70–80°C. The latent heat of phase change of paraffin is approximately 149 J / g, and the thermal conductivity of the metal matrix material ranges from 7.8 to 22.1 W / (m·K). Compared with traditional heat dissipation materials, it has superior heat dissipation performance. Experimental data show that within the phase change temperature range, this material can effectively slow down the temperature rise of the motor stator and rotor, improve motor efficiency, avoid damage caused by overheating, and extend the service life of the motor.

[0062] The solid-solid phase change material in this embodiment is mainly used in electro-hydraulic energy systems, high-power motors, and other motor equipment with high heat dissipation requirements. Especially in the optimized design and implementation of motor heat dissipation solutions, it can effectively improve the heat dissipation performance of motors, ensuring efficient operation under high load and high temperature environments. This material can also be applied in aerospace, electric vehicles, industrial automation, and other fields, and is suitable for various high-temperature and high-power application environments with stringent motor heat dissipation requirements.

[0063] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A composite discrete finned motor heat dissipation system based on solid-solid phase change materials, comprising a motor housing (1) and composite discrete fins (2), characterized in that: The composite discrete ribs (2) are sleeved on the outer wall of the motor housing (1) and are distributed at equal intervals. The composite discrete ribs (2) are made of solid-solid phase change material. The solid-solid phase change material is composed of a metal matrix and a phase change material. The metal matrix is ​​a porous metal foam material, and the phase change material is paraffin wax. The paraffin wax and expanded graphite are encapsulated inside the porous metal foam material by physical adsorption. The specific preparation method of the solid-solid phase change material includes the following steps: A1. First, the porous metal foam material is immersed in hydrochloric acid solution for pickling, then ultrasonically cleaned with deionized water, and then dried for later use. The percentage concentration of the hydrochloric acid solution is 10%, and the mass ratio of paraffin wax to expanded graphite is 20:1 to 3. A2. Heat solid paraffin wax until it is completely melted, then mix and stir the pre-prepared expanded graphite with paraffin wax according to the preset mass ratio to form a paraffin wax-expanded graphite mixture. A3. The dried porous metal foam material is completely immersed in the paraffin-expanded graphite mixture. The pressure difference drives the mixture to penetrate into the pores of the porous metal foam material. After the pores are completely filled, the mixture is left to stand in a constant temperature environment to obtain a composite sample. A4. After the composite sample was kept at a constant temperature, it was cooled and solidified. The paraffin wax shrank in the pores of the porous metal foam material to form microencapsulated closed units, thus obtaining a solid-solid phase change material. The porous metal foam material is prepared by powder metallurgy from metal alloy powder, Mn powder, and B powder. The mass ratio of the metal alloy powder, Mn powder, and B powder is 94-96:3-4:1-2. The metal alloy powder is selected from either nickel-titanium alloy powder or copper-chromium-zirconium alloy powder. The preparation method of the porous metal foam material is as follows: B1. Mix the metal alloy powder, Mn powder and B powder evenly according to the preset mass ratio to obtain a metal powder mixture; B2. Mix the metal powder mixture with pre-weighed NaCl powder at a volume ratio of 40:60 to 70:30 to ensure uniform powder distribution and obtain a mixed powder. B3. The prepared mixed powder is loaded into a mold and cold-pressed to form a green body; B4. Place the cold-molded green body into distilled water for desalination treatment; B5. The desalted green body is sintered under vacuum conditions, and after sintering, it is cooled to room temperature to produce a porous metal foam material.

2. The composite discrete finned motor heat dissipation system based on solid-solid phase change material according to claim 1, characterized in that: The pressure of cold molding after the mixed powder is loaded into the mold is set to 300-800 MPa. The green body after cold molding is desalted in distilled water at 60-85°C for 1-3 days.

3. The composite discrete finned motor heat dissipation system based on solid-solid phase change material according to claim 1, characterized in that: When the green body is sintered under vacuum conditions, it is first heated to 100-200°C at a rate of 5°C / min and held for 0.5-1h, then heated to 650-700°C at a rate of 5°C / min and held for 0.5-1h, then heated to 950-1100°C at a rate of 3°C / min and held for 0.5-5h, and finally cooled to room temperature at a rate of 7°C / min.

4. The composite discrete finned motor heat dissipation system based on solid-solid phase change material according to claim 1, characterized in that: The motor housing (1) is fixed with a distribution plate (3) and a swash plate assembly (8) at both ends. The swash plate assembly (8) is provided with a hydraulic oil inlet (4). The lower part of the motor housing (1) near the swash plate assembly (8) is provided with a hydraulic oil outlet (5). The motor housing (1) is provided with an oil chamber (11) inside. The oil chamber (11) is filled with hydraulic oil. The motor housing (1) is rotatably connected to a motor rotor (7). The outer wall of the motor rotor (7) is fixed with a motor electromagnetic plate (6). The outer wall of the motor electromagnetic plate (6) is fixed with an electromagnetic copper strip (9). The inner wall of the motor housing (1) is connected to a motor winding (10) through a motor stator (12).

Images