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

Abstract

The invention discloses a composite discrete fin motor heat dissipation system based on a 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 composite discrete fins, the composite discrete fins sleeve the outer wall of the motor shell and are distributed at equal intervals, and the composite discrete fins are made of the solid-solid phase change material; the solid-solid phase change material composite structure made of the metal matrix and the phase change material is adopted as the composite discrete fins, thermal shock can be relieved and the heat dissipation capacity can be enhanced in the working process of the motor, the solid-solid phase change material absorbs heat in a solid state through phase change, temperature change can be effectively adjusted when the load of the motor changes, and the service life of the motor is prolonged. Temperature rise of a stator and a rotor of the motor can be effectively slowed down, the working efficiency of the motor is improved, damage caused by overheating is avoided, the service life of the motor is prolonged, it is ensured that the motor operates within the efficient and safe working temperature range, and compared with a traditional heat dissipation material, the heat dissipation performance is better.

Description

Technical Field

[0001] The present invention relates to the technical field of motor heat dissipation, and in particular to a composite discrete fin motor heat dissipation system based on solid-solid phase change material. Background Art

[0002] With the widespread use of electro-hydraulic energy systems and high-power motors, motors generate significant heat under high loads and prolonged operation, causing internal motor temperatures to rise, seriously impacting their efficiency and service life. While traditional motor cooling methods, such as air cooling and water cooling, can address this issue to a certain extent, they often struggle to meet the cooling requirements of high-power motors, particularly under overload conditions and rapid load fluctuations.

[0003] In motor design, fins are often used to dissipate heat. However, traditional heat dissipation fins are mostly made of a single material, which limits their thermal conductivity and heat dissipation efficiency. To improve the heat dissipation capabilities of motors, researchers have recently proposed using phase change materials (PCMs) to regulate temperature changes. Phase change materials can absorb large amounts of heat during the phase change process, thereby slowing down the temperature rise. However, traditional phase change materials are mostly solid-liquid phase change materials, which have fluidity issues and leakage risks in practical applications. Therefore, how to combine the advantages of phase change materials with the heat dissipation structure of motors has become a major technical challenge.

[0004] To address this issue, solid-solid phase change materials (SPCMs), a new type of phase change material, have attracted widespread attention because they remain solid during the phase change process, avoiding the leakage problems of liquid phase change materials. By undergoing a phase change within a specific temperature range, SPCMs can effectively absorb heat and regulate temperature fluctuations in high-temperature environments. Their high thermal conductivity also effectively improves heat dissipation.

[0005] However, there is little research on the application of solid-solid phase change materials in motor cooling ribs in the existing technology, and the effective combination of solid-solid phase change materials and motor ribs has not yet been achieved, and there is a lack of optimized design for specific application scenarios. Therefore, the present invention proposes a composite discrete fin motor cooling system based on solid-solid phase change materials to solve the problems existing in the existing technology. Summary of the Invention

[0006] In response to the above problems, the purpose of the present invention is to propose a composite discrete fin motor heat dissipation system based on solid-solid phase change material, aiming to solve the problem of insufficient motor heat dissipation performance through the design and optimization of composite materials.

[0007] In order to achieve the purpose of the present invention, the present invention is implemented through the following technical solutions: a composite discrete fin motor heat dissipation system based on solid-solid phase change material, including a motor housing and composite discrete fins, 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 adopts a porous metal foam material, the phase change material is paraffin, and the paraffin is combined with expanded graphite by physical adsorption and encapsulated inside the porous metal foam material.

[0008] A further improvement is that the specific preparation method of the solid-solid phase change material includes the following steps:

[0009] A1. First, the porous metal foam material is immersed in a hydrochloric acid solution for pickling, then ultrasonically cleaned with deionized water, and then dried for use;

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

[0011] A3. Completely immersing the dried porous metal foam material in a paraffin-expanded graphite mixture, driving the mixture into the pores of the porous metal foam material using a pressure difference, and allowing the mixture to stand at a constant temperature until the pores are completely filled, thereby obtaining a composite sample;

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

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

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

[0015] A further improvement is that the porous metal foam material has a preparation method as follows:

[0016] B1. uniformly mixing the metal alloy powder, Mn powder and B powder according to a preset mass ratio to prepare a metal powder mixture;

[0017] B2. Mix the metal powder mixture with pre-weighed NaCl powder at a volume fraction of 40 to 70%, ensuring that the powders are evenly distributed to prepare a mixed powder;

[0018] B3, the obtained mixed powder is loaded into a mold, and cold molded to obtain 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 cooled to room temperature after sintering to obtain 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 that when the green body is sintered under vacuum conditions, the temperature is first increased to 100-200°C at a rate of 5°C / min, kept warm for 0.5-1h, then increased to 650-700°C at a rate of 5°C / min, kept warm for 0.5-1h, then increased to 950-1100°C at a rate of 3°C / min, kept warm for 0.5-5h, and finally cooled to room temperature at a rate of 7°C / min.

[0023] A further improvement is that: a distribution plate and a swash plate assembly are respectively fixed at both ends of the motor housing, a hydraulic oil inlet is provided on the swash plate assembly, a hydraulic oil outlet is provided at the lower part of the motor housing close to the swash plate assembly, an oil cavity is provided inside the motor housing, and the oil cavity is filled with hydraulic oil, a motor rotor is rotatably connected inside the motor housing, a motor electromagnetic sheet is fixed to the outer wall of the motor rotor, an electromagnetic copper bar is fixed to the outer wall of the motor electromagnetic sheet, and the inner wall of the motor housing is connected to the motor winding 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 the 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 the present invention maintains a solid state 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 the present invention can regulate the absorption and release of heat within the phase change temperature range during the operation of the motor, ensuring the temperature stability of the motor under high load and harsh working conditions, thereby improving the reliability and service life of the motor;

[0027] The material of the composite discrete fins of the present invention itself has high thermal conductivity and thermal management capabilities, which can effectively reduce the volume and weight of the motor heat dissipation system while ensuring stronger heat dissipation capabilities, and is suitable for the heat dissipation needs of high-power motors. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 3D schematic diagram of the heat dissipation system of a composite discrete fin motor based on solid-solid phase change material of the present invention;

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

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

[0031] Figure 4 Schematic diagram of the stability and thermal decomposition characteristics test of the composite discrete fins of the present invention;

[0032] Figure 5 is a scanning electron microscope (SEM) image of the porous metal foam material of the present invention;

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

[0034] Figure 7 Schematic diagram of temperature comparison curves of different components of the present invention with and without solid-solid phase change materials;

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

[0036] Among them: 1. Motor housing; 2. Composite discrete fins; 3. Distribution plate; 4. Hydraulic oil inlet; 5. Hydraulic oil outlet; 6. Motor electromagnetic plate; 7. Motor rotor; 8. Swash plate assembly; 9. Electromagnetic copper bar; 10. Motor winding; 11. Oil cavity; 12. Motor stator. DETAILED DESCRIPTION

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall 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 Ampere force. It generates torque through the interaction between the magnetic field and the current to drive mechanical motion. The motor is the core power device of modern industry and life, and its performance directly affects the efficiency and reliability of the equipment.

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

[0040] Motor cooling is the process of actively or passively dissipating the heat generated during motor operation to maintain its temperature within a safe range and ensure efficiency, life, and reliability. The motor cooling solution must be selected based on the power level, operating environment, and cost.

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

[0042] The composite discrete fin 2 is made of a solid-solid phase change material, which utilizes the phase change heat storage characteristics of the solid-solid phase change material to effectively relieve thermal shock and enhance heat dissipation capacity during operation of the motor. The solid-solid phase change material is composed of a high-thermal-conductivity metal matrix and a low-phase-change-temperature phase change material, which can relieve thermal shock and enhance heat dissipation capacity during operation of the motor. The metal matrix is a porous metal foam material, which is used to improve the overall thermal conductivity. The phase change material is paraffin, which has a high latent heat of phase change between 60°C and 70°C, and 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. The paraffin is packaged inside the porous metal foam material in a physical adsorption manner with expanded graphite to enhance the heat dissipation performance. The solid-solid phase change material absorbs heat through phase change in the solid state, and can effectively adjust the temperature change when the motor load changes, ensuring that the motor operates in an efficient and safe temperature range.

[0043] The solid-solid phase change material of the embodiment is prepared by the following steps:

[0044] A1, first, the porous metal foam material is immersed in a 10% hydrochloric acid solution for pickling for 10 min to remove surface oxides, then ultrasonic cleaned with deionized water three times, and finally dried in a 120°C oven for 2 hours for standby, completing the pretreatment of the porous metal foam material to ensure that the surface of the porous metal foam material is clean and the capillary adsorption capacity is enhanced;

[0045] A2, heat the solid paraffin to above 70°C to completely melt it, and gradually add expanded graphite powder to the molten paraffin at a paraffin to expanded graphite mass ratio of 20:1 to 3 (10:1 is used in this embodiment), first mechanically stir at 800 rpm for 30 min to preliminarily disperse, and then break the agglomeration by ultrasonic treatment for 20 min to form a uniform and stable paraffin-expanded graphite mixture. The temperature is maintained at 75-85°C throughout to prevent the paraffin from solidifying;

[0046] A3, immerse the pretreated porous metal foam material completely in the paraffin-expanded graphite mixture, transfer to a vacuum chamber and vacuumize to -0.1 MPa, maintain pressure for 60 min to fully discharge air bubbles, and after slowly breaking the vacuum, use the pressure difference to drive the mixture to penetrate into the pores of the porous metal foam material. Repeat the immersion-vacuumizing process 3 times to ensure complete filling of the pores, and finally place at 80°C for 2 hours to strengthen the adsorption effect with the capillary force of the metal pores to obtain the composite sample;

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

[0048] The porous metal foam material of this embodiment 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 ratio of 94:4:2 is adopted in this embodiment). The metal alloy powder is selected from one of 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 of this embodiment is prepared according to the following steps:

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

[0051] B2. The prepared metal powder mixture is mixed with pre-weighed NaCl powder at a volume fraction of 40 to 70% (55% volume fraction is used in this embodiment) to ensure that the powders are evenly distributed to prepare a mixed powder;

[0052] B3, the obtained mixed powder is loaded into a mold, and cold molded at a pressure of 300-800 MPa to obtain a green body;

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

[0054] B5. The desalted green body was sintered under vacuum conditions. The temperature was first raised to 150°C at a rate of 5°C / min and kept at this temperature for 0.75h. The temperature was then raised to 675°C at a rate of 5°C / min and kept at this temperature for 0.8h. The temperature was then raised to 1000°C at a rate of 3°C / min and kept at this temperature for 3h. Finally, the temperature was lowered to room temperature at a rate of 7°C / min to obtain 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, and is suitable for heat dissipation applications in high-temperature working environments.

[0056] Figure 4 Schematic diagram showing 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 microscope (SEM) images of porous metal foam materials (Ni-Mn-Ti-B) are used to intuitively display the pore distribution, morphology and microstructure of the metal foam.

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

[0059] Figure 7 The curves show the time-dependent temperature evolution of the composite discrete fins 2 and the hydraulic oil under different thermal management configurations, systematically comparing the heat dissipation performance of fins without and with solid-solid phase change materials. The results show that the composite discrete fins 2 enter the phase change range early in operation, significantly suppressing the temperature rise rate by absorbing latent heat and effectively reducing the overall thermal load of the system. Compared with conventional metal fins, they demonstrate superior thermal control performance in maintaining temperature stability, validating the engineering feasibility and application value of solid-solid phase change materials in thermal management of motors and hydraulic systems.

[0060] Figure 8 Shows the temperature profile cloud of the motor in the Y direction ( Figure 8 Part a in the figure is the cross-sectional temperature cloud diagram of the motor without phase change material. Figure 8 Part b in the figure shows the temperature cloud 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 reduce the overall temperature of the motor, demonstrating a good thermal control optimization effect.

[0061] The phase change temperature range of the solid-solid phase change material in this embodiment is set to 70-80°C, the phase change latent heat of paraffin is approximately 149 J / g, and the thermal conductivity range of the metal matrix material is 7.8-22.1 W / (m·K). Compared with traditional heat dissipation materials, it has better 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 the motor's operating efficiency, avoid damage caused by overheating, and extend the motor's service life.

[0062] The solid-solid phase change material of this embodiment is primarily used in electro-hydraulic energy systems, high-power motors, and other motor-related equipment with stringent heat dissipation requirements. In particular, the optimized design and implementation of motor heat dissipation solutions effectively improves the motor's heat dissipation performance, ensuring efficient operation under high loads and high temperatures. This material can also be used in aerospace, electric vehicles, industrial automation, and other fields, and is suitable for various high-temperature, high-power applications with stringent heat dissipation requirements.

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

Claims

1. A composite discrete fin motor heat dissipation system based on solid-solid phase change material, comprising a motor housing (1) and composite discrete fins (2), characterized in that: The composite discrete fins (2) are sleeved on the outer wall of the motor housing (1) and are distributed at equal intervals. The composite discrete fins (2) are made of a 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. The paraffin is combined with expanded graphite and is encapsulated in the porous metal foam material by physical adsorption.

2. The composite discrete fin motor heat dissipation system based on solid-solid phase change material according to claim 1, characterized in that: The specific preparation method of the solid-solid phase change material comprises the following steps: A1. First, the porous metal foam material is immersed in a hydrochloric acid solution for pickling, then ultrasonically cleaned with deionized water, and then dried for use; A2. Heat the solid paraffin wax until it is completely melted, and then mix the pre-prepared expanded graphite with the paraffin wax according to a preset mass ratio to form a paraffin wax-expanded graphite mixture; A3. Completely immersing the dried porous metal foam material in a paraffin-expanded graphite mixture, driving the mixture into the pores of the porous metal foam material using a pressure difference, and allowing the mixture to stand at a constant temperature until the pores are completely filled, thereby obtaining a composite sample; A4. The composite sample is cooled and solidified after being kept at a constant temperature. The paraffin shrinks in the pores of the porous metal foam material to form microencapsulated closed units, thereby preparing a solid-solid phase change material.

3. The composite discrete fin motor heat dissipation system based on solid-solid phase change material according to claim 2, characterized in that: The percentage concentration of the hydrochloric acid solution is 10%, and the mixing mass ratio of the paraffin wax to the expanded graphite is 20:1-3.

4. The composite discrete fin motor heat dissipation system based on solid-solid phase change material according to claim 1, characterized in that: The porous metal foam material is prepared from metal alloy powder, Mn powder and B powder by powder metallurgy, wherein the mixing mass ratio of the metal alloy powder, Mn powder and B powder is 94-96:3-4:1-2, and the metal alloy powder is selected from one of nickel-titanium alloy powder and copper-chromium-zirconium alloy powder.

5. The composite discrete fin motor heat dissipation system based on solid-solid phase change material according to claim 1 is characterized in that The porous metal foam material has the following preparation method: B1. uniformly mixing the metal alloy powder, Mn powder and B powder according to a preset mass ratio to prepare a metal powder mixture; B2. Mix the metal powder mixture with pre-weighed NaCl powder at a volume fraction of 40 to 70%, ensuring that the powders are evenly distributed to prepare a mixed powder; B3, the obtained mixed powder is loaded into a mold, and cold molded to obtain 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 cooled to room temperature after sintering to obtain a porous metal foam material.

6. The composite discrete fin motor heat dissipation system based on solid-solid phase change material according to claim 5, characterized in that: The mixed powder is loaded into a mold and then cold-molded at a pressure of 300-800 MPa. The green body after cold molding is desalted in distilled water at 60-85° C. for 1-3 days.

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

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

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