Ultrasonic-microchannel integrated nanofluid dynamic heat dissipation system and method

Abstract

The invention belongs to the technical field of efficient heat management, and relates to a nanofluid enhanced heat exchange system based on a built-in ultrasonic device, which comprises an integrated micro-channel cooling plate 2, an embedded ultrasonic device 3, a nanofluid circulating system and an intelligent control system 5, the integrated micro-channel cooling plate 2 is attached to the surface of a heating device 1 (such as a solar cell panel), and the embedded ultrasonic device 3 is attached to the surface of the heating device 1. A groove is formed in the side, away from the heating device 1, of the integrated micro-channel cooling plate 2, the embedded ultrasonic device 3 is installed in the groove, and the nano-fluid circulating system and the embedded ultrasonic device 3 are in electric signal connection with the intelligent control system. The invention can effectively solve the industrial problems of high-temperature efficiency reduction, nanofluid agglomeration instability and the like of the solar cell panel, improve the heat dissipation efficiency and improve the conversion efficiency of the cell panel.

Description

Technical Field

[0001] The present invention belongs to the field of efficient thermal management technology and proposes a nanofluid dynamic heat dissipation system based on a built-in ultrasonic device. Targeting high-heat-generating scenarios such as solar panels, the system achieves synergistic enhancement of nanofluid dispersion and efficient heat transfer through the integrated design of a microchannel cooling plate and an embedded ultrasonic transducer. Background Art

[0002] With the rapid development of the photovoltaic industry and the continuous increase in solar panel power density, traditional thermal management technologies are no longer able to meet the demand for efficient heat dissipation. Research shows that for every 1°C increase in solar panel operating temperature, the photoelectric conversion efficiency decreases by approximately 0.4%. Traditional air cooling and pure water circulation systems, due to their low heat transfer coefficient and insufficient convective heat transfer capacity, cause solar panels to operate in the 55-65°C high temperature range for a long time, significantly reducing power generation efficiency and equipment life.

[0003] Nanofluids, by dispersing highly thermally conductive nanoparticles (such as Al2O3 and graphene) within a base fluid, can increase the fluid's thermal conductivity by 30%-70%, offering a new path to breaking through the bottleneck of traditional heat dissipation. However, in practice, nanoparticles easily aggregate under the influence of high temperatures (up to 80°C) and shear forces of the fluid. This reduces the nanofluid's effective heat conduction path, lowering its thermal conductivity and negating the material's advantages.

[0004] Existing solutions have significant drawbacks: traditional surfactants easily decompose and become ineffective at high temperatures, and the introduction of impurities increases thermal resistance. Offline ultrasonic dispersion requires periodic interruptions to the system, making it incapable of meeting the continuous power generation requirements of solar power plants. External ultrasonic equipment is bulky, making it difficult to adapt to the compact structure of solar panels, and consumes as much as 20-50 watts, undermining its energy-saving advantages. Therefore, the development of a highly integrated, dynamically anti-agglomeration, and self-powered nanofluid thermal management technology has become an urgent industry need.

[0005] Although the built-in ultrasonic device provides a new idea for nanofluid dispersion, the existing solution still has technical bottlenecks: the separation of the traditional ultrasonic transducer and the cooling structure leads to low acoustic energy transmission efficiency and the inability to dynamically adjust parameters according to the real-time temperature of the solar panel; there is a lack of coordinated optimization of the ultrasonic cavitation effect and nanofluid heat transfer, making it difficult to fully utilize the coupling advantages of the two.

[0006] In light of this background, the present invention proposes a solar panel thermal management system based on ultrasonically dispersed nanofluids. This system, through the integrated design of a microchannel cooling plate and ultrasonic transducer, achieves a dual breakthrough in both dynamic nanoparticle dispersion and efficient heat dissipation. The system utilizes microjets generated by ultrasonic cavitation to disrupt particle agglomeration in real time. Combined with intelligent PID control of ultrasonic power and frequency, the system ensures stable operation of the nanofluid over a wide temperature range of -40°C to 150°C. Furthermore, the system innovatively utilizes a self-powered solar panel mode to reduce external reliance, providing an efficient, economical, and sustainable heat dissipation solution for the photovoltaic industry. Summary of the Invention

[0007] The present invention aims to propose a solar panel thermal management system and method based on ultrasonically dispersed nanofluids. Through the integrated design of an ultrasonic device and a microchannel cooling plate, as well as an intelligent dynamic control strategy, the excellent thermal conductivity of nanofluids is utilized to achieve efficient heat dissipation and stable operation of solar panels, significantly improving the photoelectric conversion efficiency and system economy.

[0008] The technical solution adopted by the present invention is: a nanofluid enhanced heat exchange system based on a built-in ultrasonic device, including an integrated microchannel cooling plate 2, an embedded ultrasonic device 3, a nanofluid circulation system and an intelligent control system 5. The integrated microchannel cooling plate 2 is attached to the surface of a heating device 1 (such as a solar panel). The side of the integrated microchannel cooling plate 2 facing away from the heating device 1 has a groove, and the embedded ultrasonic device 3 is installed in the groove. The nanofluid circulation system and the embedded ultrasonic device 3 are electrically connected to the intelligent control system.

[0009] The integrated microchannel cooling plate 2 is made of aluminum alloy or copper, and has a microchannel 4 for the nanofluid to flow through processed inside. The grooves are multiple grooves of the same size arranged in an array. The number of embedded ultrasonic devices is the same as the number of grooves, and an embedded ultrasonic device is installed in each groove.

[0010] The nanofluid circulation system includes a microchannel 4, a nanofluid storage tank 9, a heat exchanger 8, a pump 7 and a connecting pipe. The pump electrical signal is connected to the intelligent control system. The nanofluid is a mixed system including high thermal conductivity nanoparticles (such as graphene, Al2O3, CuO) and a base liquid (water / ethylene glycol / silicone oil).

[0011] The embedded ultrasonic device 3 is a piezoelectric ceramic transducer.

[0012] When the temperature of the heating device is greater than the set threshold, the ultrasonic transducer is automatically switched to the high-frequency and high-power mode. When the temperature of the heating device is less than or equal to the set threshold, the ultrasonic transducer is automatically switched to the normal power mode.

[0013] There is high thermal conductivity nano silver glue between the integrated microchannel cooling plate 2 and the heating device 1.

[0014] The present invention utilizes an integrated ultrasound-microchannel design, breaking away from the traditional separate structure by embedding high-frequency ultrasonic transducers (frequency 20-100kHz, power 50-300W) within a microchannel cooling plate. The cooling plate is constructed of aluminum alloy / copper, with a microchannel inner diameter of 1-10mm. The transducers are arranged in a staggered array (spacing 1-5cm), ensuring uniform acoustic coverage and adapting to the compact installation requirements of flexible or rigid solar panels. The present invention synergistically enhances nanofluid dynamic dispersion and heat transfer: it utilizes ultrasonic cavitation-generated microjets (velocity >100m / s) and acoustic streaming to disrupt nanoparticle agglomerates in real time. By controlling the ultrasonic pulse and adjusting the cavitation bubble diameter, the nanoparticles form a stable dispersion. Furthermore, the ultrasound-induced enhanced fluid turbulence combines with the enhanced thermal conductivity of the nanoparticles to improve the convective heat transfer coefficient. The present invention utilizes an intelligent adaptive control system: temperature sensors are integrated at the microchannel inlet and outlet, and a PID controller optimizes ultrasonic parameters in real time. When the temperature of the solar panel is high (such as >60℃), it automatically switches to high-frequency and high-power mode (frequency ≥40kHz, power ≥200W); when the temperature is maintained at 40-50℃, it enters energy-saving mode (power 50W), the system energy consumption is less than 5W, and the battery panel output power can be used for self-power, achieving "zero external energy consumption" operation.

[0015] 1) Integrated microchannel cooling plate: Substrate structure: A microchannel cooling plate is directly integrated under the photovoltaic cell and is made of aluminum alloy / copper.

[0016] Thermal coupling design: High thermal conductivity nano-silver glue (thermal conductivity ≥ 100W / m·K) is coated between the battery cell and the cooling plate to reduce contact thermal resistance.

[0017] Embedded ultrasonic device: A groove is machined on the back of the cooling plate, and the piezoelectric ceramic transducer is bonded to the substrate using thermally conductive epoxy resin (thermal conductivity ≥ 2W / m·K). This ensures efficient transmission of acoustic energy and suppresses particle agglomeration through ultrasonic dynamic dispersion, extending the stable period of the nanofluid.

[0018] Transducer array: uses piezoelectric ceramic transducers arranged in a staggered pattern, and achieves independent control and signal transmission through a flexible printed circuit board (FPC).

[0019] Through the above innovative design, the present invention can effectively solve industry problems such as high-temperature efficiency reduction of solar panels and nanofluid agglomeration and instability, improve heat dissipation efficiency, and increase the conversion efficiency of solar panels. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic diagram of a nanofluid circulation system; FIG2 is a cross-sectional view of the structure of the present invention; Among them, 1. Heating device, 2. Integrated microchannel cooling plate, 3. Embedded ultrasonic device, 4. Microchannel, 5. Intelligent control system, 6. High thermal conductivity nano-silver glue, 7. Pump, 8. Heat exchanger, 9. Nanofluid storage tank. DETAILED DESCRIPTION

[0021] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and with reference to preferred embodiments.

[0022] Nanofluid circulation system: like Figure 1 As shown, the nanofluid circulation system includes a microchannel 4, a nanofluid storage tank 9, a heat exchanger 8, a pump 7 and a connecting pipe. The pump electrical signal is connected to the intelligent control system. The nanofluid is a mixed system including high thermal conductivity nanoparticles (such as graphene, Al2O3, CuO) and a base liquid (water / ethylene glycol / silicone oil). In one embodiment, the working fluid is selected as follows: a water / ethylene glycol / silicone oil-based mixed nanofluid is selected, 0.1-1.0wt% graphene is added, and a wide temperature range (-40°C ~ 150°C) operation and high thermal conductivity are taken into consideration.

[0023] Circulation power: A circulating medium delivery pump (pump 7) is used in conjunction with a cooling plate to release heat to the outside.

[0024] like Figure 2 As shown, the integrated microchannel cooling plate: Substrate structure: A microchannel cooling plate is directly integrated under the photovoltaic cell (heat generating device 1) and is made of aluminum alloy / copper.

[0025] Thermal coupling design: High thermal conductivity nano-silver glue (thermal conductivity ≥ 100W / m·K) is coated between the battery cell and the cooling plate to reduce contact thermal resistance.

[0026] Embedded ultrasonic device: A groove is machined on the back of the cooling plate, and the piezoelectric ceramic transducer is bonded to the substrate using thermally conductive epoxy resin (thermal conductivity ≥ 2W / m·K). This ensures efficient transmission of acoustic energy and suppresses particle agglomeration through ultrasonic dynamic dispersion, extending the stable period of the nanofluid.

[0027] Transducer array: uses piezoelectric ceramic transducers arranged in a staggered pattern, and achieves independent control and signal transmission through a flexible printed circuit board (FPC).

[0028] Heating devices: Conventional crystalline silicon or thin-film solar panels are used. The bottom of the panel is tightly bonded to the integrated microchannel cooling plate using highly thermally conductive nano-silver adhesive. The adhesive has a thermal conductivity of ≥100W / m·K and a thickness of 50-100μm, ensuring that heat generated by the panel is quickly transferred to the cooling plate. A continuous aluminum alloy layer (or copper layer) at least 0.5-2mm thick is retained on the top of the microchannel cooling plate as an isolation barrier, isolating the microchannels from the panel to prevent liquid leakage.

[0029] Integrated microchannel cooling plate: The base structure can be made of aluminum alloy through precision die-casting, with an overall thickness of 10mm. Inside, several rows of parallel rectangular microchannels are machined. The microchannels are 5mm wide, 8mm apart, and the channel length matches the width of the solar panel. The cooling plate's dimensions must be considered in conjunction with other components, such as the contact area with the solar panel and the connection dimensions for the circulation pump and piping. The cooling plate's overall dimensions should perfectly match the solar panel to ensure good heat transfer.

[0030] Embedded ultrasonic device: Grooves matching the piezoelectric ceramic transducers are machined on the back of the cooling plate. The transducers measure 10mm × 10mm × 0.8mm, have a frequency of 40kHz, and a power of 100W. Five transducers are installed in each microchannel row, arranged in a staggered array. The transducers are bonded to the substrate with a thermally conductive epoxy resin with a thermal conductivity of ≥2W / m·K to ensure efficient transmission of acoustic energy. Independent control and signal transmission are achieved through a flexible printed circuit board (FPC).

[0031] Nanofluid circulation system: Utilizes a 0.8wt% Al2O3-CuO / water mixed nanofluid. The Al2O3 nanoparticles have a particle size of 30nm, the CuO nanoparticles have a particle size of 25nm, and the base fluid is deionized water. A circulation pump pumps the nanofluid from the reservoir into the microchannel cooling plate. After absorbing heat from the solar panels, the nanofluid enters the heat exchanger for dissipation before returning to the reservoir, forming a closed loop. Other auxiliary components include flow sensors and pressure sensors installed in the circulation system for real-time monitoring of the nanofluid's flow and pressure. A liquid level sensor is also installed within the reservoir.

[0032] Intelligent control system: Temperature sensors and conductivity sensors are integrated at the inlet and outlet of the microchannel cooling plate. The temperature sensor uses a platinum resistance temperature sensor, and the conductivity sensor is used to monitor the dispersion state of the nanoparticles. The PID controller adjusts the power, frequency, and pulse duty cycle of the ultrasonic device, as well as the flow rate of the circulation pump in real time based on the sensor feedback data. When the panel temperature is greater than 60°C, the ultrasonic device automatically switches to 200W power, 40kHz frequency, and continuous wave mode to perform initial dispersion treatment on the nanofluid, and increases the flow rate of the circulation pump to enhance the ultrasonic dispersion and fluid circulation capabilities; when the temperature is maintained at 40-50°C, the ultrasonic power is reduced to 50W, the frequency is 20kHz, and the circulation pump maintains a low flow rate.

[0033] During low-light periods each week at night, the system automatically performs a self-cleaning routine. During this time, the circulation system switches to cleaning mode, injecting a mixture of deionized water and surfactants. The ultrasonic device operates at a high frequency of 60kHz and a power of 150W for 15 minutes, using the ultrasonic cavitation effect to remove impurities and deposited particles that may have adhered to the inner walls of the microchannels. Once cleaning is complete, the system automatically switches back to normal operation and replenishes with fresh nanofluid.

Claims

1. A nanofluid enhanced heat exchange system based on a built-in ultrasonic device, characterized by: The invention comprises an integrated microchannel cooling plate (2), an embedded ultrasonic device (3), a nanofluid circulation system and an intelligent control system (5), wherein the integrated microchannel cooling plate (2) is attached to the surface of the heating device (1), a groove is provided on the side of the integrated microchannel cooling plate (2) facing away from the heating device (1), the embedded ultrasonic device (3) is installed in the groove, and the nanofluid circulation system and the embedded ultrasonic device (3) are electrically connected to the intelligent control system.

2. The nanofluid enhanced heat exchange system based on a built-in ultrasonic device according to claim 1, characterized in that: The integrated microchannel cooling plate (2) is made of aluminum alloy or copper, and is internally processed with microchannels (4) for the nanofluid to flow through. The grooves are multiple grooves of the same size arranged in an array, and the number of embedded ultrasonic devices is the same as the number of grooves, with one embedded ultrasonic device installed in each groove.

3. The nanofluid enhanced heat exchange system based on a built-in ultrasonic device according to claim 2, characterized in that: The nanofluid circulation system includes a microchannel (4), a nanofluid storage tank (9), a heat exchanger (8), a pump (7) and a connecting pipe. The pump electrical signal is connected to the intelligent control system. The nanofluid is a mixed system including high thermal conductivity nanoparticles (such as graphene, Al2O3, CuO) and a base liquid (water / ethylene glycol / silicone oil).

4. The nanofluid enhanced heat exchange system based on a built-in ultrasonic device according to claim 1, characterized in that: The embedded ultrasonic device (3) is a piezoelectric ceramic transducer.

5. The nanofluid enhanced heat exchange system based on a built-in ultrasonic device according to claim 1, characterized in that: When the temperature of the heating device is greater than the set threshold, the ultrasonic transducer is automatically switched to the high-frequency and high-power mode. When the temperature of the heating device is less than or equal to the set threshold, the ultrasonic transducer is automatically switched to the normal power mode.

6. The nanofluid enhanced heat exchange system based on a built-in ultrasonic device according to claim 1, characterized in that: There is high thermal conductivity nano silver glue between the integrated microchannel cooling plate (2) and the heating device (1).

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