Heat dissipation method of high-power LED lighting equipment

Abstract

The invention belongs to the technical field of heat dissipation, and discloses a heat dissipation method of high-power LED lighting equipment. Heat generated when the power supply works is conducted to the outer frame of the lighting equipment through the heat conduction material, and the heat is further radiated to the outside air through the radiation refrigeration coating, so that a good heat dissipation effect is achieved. The heat-conducting material is a silicon-based heat-conducting gasket and is formed by mixing a silicon rubber matrix, silicone oil, a heat-conducting filler and other auxiliaries; the radiation refrigeration coating is prepared by mixing and dispersing a film-forming substance, a radiation functional filler, a reflection functional filler and other auxiliaries. The working temperature of the internal power supply is greatly reduced through the synergistic effect of the radiation refrigeration coating and the internal heat conduction material in the synergistic mode of natural conduction, convection and radiation. Meanwhile, the heat dissipation mode of the radiation refrigeration coating does not depend on heat convection of the external environment, the number of heat dissipation fins on the lighting equipment can be effectively reduced, and therefore the purpose of weight reduction is achieved.

Description

Technical Field

[0001] This application relates to the technical field of heat dissipation, and particularly to a heat dissipation method for high-power LED lighting devices. Background Art

[0002] With the wide application of high-power LED lighting devices, they show significant advantages such as high energy efficiency, long lifespan, and superior light quality in outdoor lighting, industrial lighting and other fields. LED lighting devices have gradually replaced traditional light sources and become the current mainstream light sources. However, LED lighting devices, especially high-power LED lighting devices, generate a large amount of heat during operation. If the heat dissipation is insufficient, the high temperature of the chip and power supply will lead to unstable light sources, reduced luminous efficiency, and even problems such as equipment failure and inability to illuminate. This poses great challenges to the service life, performance stability, and user experience of LED devices. Therefore, the heat dissipation problem has become a major technical bottleneck restricting the wide application of high-power LED lighting devices. To address this issue, larger heat sinks and dense fin structures are often used in current heat dissipation designs to improve the heat dissipation efficiency. However, these components are often heavy, increasing the overall weight and installation complexity of the device, thus posing higher requirements for design and application. Therefore, the heat dissipation problem and the device weight reduction problem have become major technical bottlenecks restricting the wide application of high-power LED lighting devices.

[0003] At present, the heat dissipation technologies of LED lighting devices on the market mainly include two categories: passive heat dissipation and active heat dissipation. Passive heat dissipation technology does not require additional energy input, and has a simple and reliable structure. For example, Patent CN201320644056.1 discloses and authorizes a heat dissipation system for high-power LED lamps. The high-power LED lamp in this patent includes an integrated chip and a lamp housing. An air convection cavity is made on the outside of the lamp housing, and heat dissipation fins are arranged in the air convection cavity. The heat dissipation fins are connected to a heat conduction tube and a graphite heat conduction base. The heat generated when the LED lamp chip works is led to the heat dissipation fins through the heat conduction tube and the graphite heat conduction base, and the heat on the heat dissipation fins is dissipated into the air through the air convection in the air convection cavity, thereby reducing the temperature of the chip inside the LED lamp. Patent CN201620104932.5 discloses and authorizes a heat dissipation system for high-power remote lighting. The system includes an upper connecting ring and a lower connecting ring. A number of heat dissipation partitions are evenly arranged in the circumferential direction between the upper connecting ring and the lower connecting ring. Each heat dissipation partition is provided with a number of heat dissipation fins, and heat dissipation channels are arranged between the heat dissipation fins and between adjacent two heat dissipation fins. The heat during the operation of the device is dissipated to the surrounding environment through the heat dissipation fins on the upper and lower connecting rings, ensuring the normal operation of high power and improving the service life of the device at the same time. Patent CN201020601221.1 discloses and authorizes a heat dissipation system used in high-power lamps. The system includes wing-shaped heat dissipation fins installed on the back of the lamp, and at the same time, the wing-shaped heat dissipation fins are connected to the high-power lamp through a heat conduction panel. The heat conduction panel can quickly absorb the heat generated by the lamp body and the circuit board, and directly radiate it to the surrounding air through the heat dissipation scales, and the heat dissipation effect is good.

[0004] Although passive heat dissipation technology has a simple structure and low energy consumption, it also has some obvious disadvantages: for example, passive heat dissipation relies on natural convection and conduction, and the heat dissipation speed is relatively slow, which is difficult to meet the heat dissipation requirements of high-power LED devices. Therefore, in order to increase the heat dissipation efficiency, passive heat dissipation devices usually require larger radiators or fin designs, which in turn leads to an increase in the volume and weight of the device. At the same time, the effect of passive heat dissipation is easily affected by the ambient temperature and air flow conditions. In an environment with high temperature or poor air flow, the heat dissipation performance will decrease significantly.

[0005] Active cooling technology accelerates heat transfer or dissipation by applying external energy (such as fans, pumps, etc.), with high heat dissipation efficiency and good heat dissipation performance. For example, Patent CN202221637679.1 discloses and authorizes a high-power lamp heat dissipation system. A heat sink is arranged on one side of the LED lamp, and a cooling fan is installed on one side of the heat sink. When in use, the heat generated by the LED lamp is conducted to the heat sink through a heat-conducting copper pipe, and the cooling fan blows away the heat on the heat sink, thereby improving the heat dissipation effect of the stage lamp. Patent CN201710512562.8 discloses and authorizes a high-power LED optical path heat dissipation combined system, which is a liquid-cooling and air-cooling combined heat dissipation system, specifically including: a heat absorption device, a liquid-cooling heat sink, a fan, a liquid-cooling pipeline, and a liquid circulation pump. The fan is fixedly installed at the bottom of the liquid-cooling heat sink to form a liquid-cooling and air-cooling heat dissipation module. When the LED lamp works, the liquid-cooling pipeline transfers the heat to the liquid-cooling heat sink through liquid conduction. While the liquid-cooling heat sink dissipates part of the heat, the fan dissipates most of the heat to the external environment. Through the liquid-cooling and air-cooling combined heat dissipation system, when the ambient temperature is 25°C, the internal temperature of the LED lamp during operation can be reduced by 30°C. Patent CN202123243670.0 discloses and authorizes a water-cooling heat dissipation system designed specifically for high-power LED light sources. The system mainly includes a light output head, a host, and a water-cooling heat dissipation system. The light output head is fixedly connected to the host through mechanical connection and is connected to the water inlet of the cooling water tank in the water-cooling heat dissipation system through a water delivery pipe. When the equipment is running, the heat generated by the LED light source is quickly taken away by the circulating cooling water in the water delivery pipe and released in the cooling water tank and then circulates again. Through this closed-loop water-cooling cycle, the system can efficiently reduce the equipment temperature, not only ensuring the stable operation of the high-power LED light source but also greatly extending the service life of the equipment, and is applicable to various scenarios that require long-term continuous operation.

[0006] Although active cooling technology has high heat dissipation efficiency, it also has the following disadvantages: Active cooling relies on the operation of fans, pumps, or other devices, which additionally increases energy consumption and is somewhat contradictory to the original intention of energy conservation of LED devices. At the same time, active cooling systems usually contain more moving parts and control units, with higher design and manufacturing costs, and higher installation and maintenance requirements. Moreover, mechanical components such as fans and electric pumps also have problems of wear and aging, may malfunction, affect the normal operation of the equipment, and reduce the overall reliability of the system. Summary of the Invention

[0007] Object of the Invention: To solve the problems existing in the above-mentioned prior art, the present invention provides a heat dissipation method for high-power LED lighting equipment.

[0008] Technical solution: The heat dissipation method of the high-power LED lighting device described in the present invention conducts the heat generated during the operation of the power supply to the outer frame of the lighting device through a heat-conducting material, and further radiates the heat to the external air through the radiation cooling coating applied on the surface of the outer frame, thereby significantly reducing the operating temperature of the power supply. At the same time, due to the improved heat dissipation effect, the number of heat dissipation fins installed on the back of the LED lighting device can be appropriately reduced, which not only improves the service life of the device, but also reduces the weight of the device and the installation and transportation costs of the device.

[0009] The heat-conducting material described is a silicone-based heat-conducting gasket. The silicone-based heat-conducting gasket is composed of a silicone rubber matrix, silicone oil, heat-conducting filler, and other additives, and has good heat-conducting performance and flexibility, and is suitable for various irregularly shaped contact surfaces.

[0010] The silicone rubber matrix is one of room temperature vulcanized silicone rubber (RTV) or thermosetting silicone rubber (HTV); the heat-conducting filler is one or several of aluminum powder, copper powder, alumina, silicon nitride, graphite, boron nitride; the other additives include toughening agents, cross-linking agents, catalysts, etc. For the present invention, the silicone rubber matrix is preferably a dimethyl silicone-based matrix; the heat-conducting filler is preferably Si 3 N 4 .

[0011] The silicone-based heat-conducting gasket is obtained by the following method:

[0012] 1) First, 30-50 parts by weight of silicone rubber matrix, 30-40 parts of heat-conducting filler, 1-5 parts of toughening agent, 1-5 parts of cross-linking agent, and 0.5-1 part of catalyst are placed in a high-shear mixer and mixed for 1-2 h at a mixing speed of 500-800 r / min to obtain a uniformly mixed heat-conducting silicone rubber material.

[0013] 2) The above heat-conducting silicone rubber material is placed in a template to ensure that all voids are filled, and is cured and formed under a certain pressure and temperature, and then cooled and demolded, and processed into a certain shape.

[0014] The radiation cooling coating is prepared by mixing and dispersing a film-forming substance with radiation functional fillers, reflection functional fillers, and other additives; the film-forming substance includes epoxy resin, silicone resin, acrylic resin, polyurethane resin, fluorocarbon resin; the radiation functional fillers include MgO, Al 2 O 3 , AlN, SiO 2 , CaO, etc.; the reflection filler is TiO 2 , Y 2 O3 、 ZnO, MgF 2 , CaF 2, one or several of copper powder, silver powder, and aluminum powder. For the present invention, the film-forming substance is preferably an epoxy resin; the radiation functional filler is preferably MgO; the reflective filler is preferably TiO 2 .

[0015] The radiation cooling coating is obtained by the following method:

[0016] 1) Mix 1 - 5 parts of a dispersant and 20 - 50 parts of a film-forming substance by weight in a high-speed mixer at a rotation speed of 800 - 1000 r / min for 10 - 15 minutes until the dispersant and the film-forming substance are uniformly fused to form the basic mixture of the powder coating.

[0017] 2) Add 10 - 40 parts of a reflective filler, 10 - 40 parts of a radiation filler, and 1 - 12 parts of a wetting agent to the basic mixture. Perform melt extrusion at 120 - 140 °C through an extruder and use shear force to ensure uniform distribution of each component to obtain a functionalized powder coating mixture.

[0018] 3) Rapidly cool the extruded material to room temperature and use a pulverizer to pulverize the cooled material to the target particle size range to obtain a preliminary powder coating.

[0019] 4) Uniformly mix 1 - 5 parts of an antifoaming agent and the powder coating in a low-speed mixer at a rotation speed of 300 - 500 r / min for 5 - 10 minutes to further improve the processing and application performance of the powder coating and prepare a radiation cooling powder coating with stable performance.

[0020] Furthermore, the external frame includes an equipment housing and heat dissipation fins provided on the equipment housing, and the radiation cooling coating is coated on the outside of the equipment housing and its heat dissipation fins. The preferred coating method is electrostatic spraying.

[0021] Beneficial effects: In traditional heat dissipation technologies, the focus of heat dissipation is usually on chip heat dissipation, while the heat dissipation of the lamp power supply is ignored. However, the overall lifespan of a lamp actually depends more on the lifespan of the power supply. If the power supply is too hot during operation, its service life will be significantly reduced. Therefore, in the present invention, a heat-conducting material is installed in the gap between the power supply and the external housing, and the heat generated by the power supply during operation is effectively conducted to the external housing by the heat-conducting material. At the same time, the radiation cooling coating on the surface of the external housing can release the heat to the external environment in a radiative manner. Through the synergistic effect of the heat-conducting material and the radiation cooling coating, the temperature of the power supply can be significantly reduced, thereby improving the overall heat dissipation performance of the equipment and extending its service life.

[0022] Meanwhile, traditional heat dissipation technologies usually rely on installing heat sinks for heat dissipation. However, this method not only significantly increases the weight of the device and the transportation and installation costs, but also in an environment with high temperature or poor air flow, the heat convection heat dissipation effect of the heat sink will be significantly reduced, resulting in a decline in heat dissipation performance. The radiative cooling coating dissipates heat to the external environment through thermal radiation. Even under conditions of high temperature or poor air flow, it can still efficiently release heat, demonstrating excellent cooling performance. Therefore, coating with the radiative cooling coating can reduce the number of heat sinks while achieving the same heat dissipation effect.

[0023] In addition, the coatings commonly applied to the surface of LED devices usually only have basic functions such as weather resistance and anti-corrosion. The radiative cooling technology in the radiative cooling coating of this system utilizes the characteristics of the Earth's atmospheric window (8 - 13μm band), enabling an object to transfer heat to outer space through radiation, thereby achieving a cooling effect. Different from traditional passive heat dissipation technologies, even in an environment with high temperature or poor air flow, the radiative cooling coating can efficiently radiate heat, demonstrating excellent cooling performance. Thus, it significantly reduces the temperature of the LED device during operation. In addition, both the heat-conducting material and the radiative cooling coating dissipate heat spontaneously without the need for additional energy input, and have the advantages of small size, light weight, simple structure, and high reliability.

[0024] The present invention significantly reduces the operating temperature of the internal power supply through the synergistic manner of natural conduction, convection, and radiation, and by utilizing the synergistic effect of the radiative cooling coating and the internal heat-conducting material. At the same time, since the heat dissipation method of the radiative cooling coating does not depend on the heat convection of the external environment, it can effectively reduce the number of heat sinks on the lighting device, thereby achieving the purpose of weight reduction. Through this heat dissipation system, the limitations of traditional passive heat dissipation technologies have been successfully overcome, and the goals of efficient heat dissipation, energy conservation and emission reduction, and weight reduction and cost reduction have been achieved, providing an innovative solution for the heat dissipation of high-power LED lighting devices. Brief Description of the Drawings

[0025] Figure 1 It is a schematic diagram of the coating of the radiative cooling coating.

[0026] In the figure: 1 - lighting device bulb, 2 - device bracket, 3 - external housing of the device, a - coating area.

[0027] Figure 2 It is a physical diagram of the coating of the radiative cooling coating.

[0028] In the figure: 4 - heat sink.

[0029] Figure 3 It is a schematic diagram of the installation of the heat-conducting material.

[0030] In the figure: 5 - Internal power supply of the device; 6 - Thermal conductive material installed between the power supply and the internal housing; 7 - Housing of the lighting device.

[0031] Figure 4 It is a physical installation diagram. Specific implementation manners

[0032] The technical solutions of the present application will be described in detail below through embodiments, but the protection scope of the present application is not limited to the described embodiments.

[0033] Embodiment 1

[0034] An embodiment of the present invention provides a heat dissipation system for a high-power LED lighting device, including a radiative cooling coating applied to the external housing of the device and a thermal conductive material installed between the internal power supply of the device and the external housing.

[0035] The preparation method of the radiative cooling coating is as follows:

[0036] 1) Mix 5 parts of a dispersant and 35 parts of epoxy resin by weight in a high-speed mixer at a rotation speed of 1000 r / min for 15 minutes until the dispersant and the epoxy resin are evenly fused to form a basic mixture of the powder coating.

[0037] 2) Add 40 parts of TiO 2 , 10 parts of MgO and 8 parts of a wetting agent to the basic mixture. Perform melt extrusion at 140 °C through an extruder and use shear force to ensure uniform distribution of each component to obtain a functionalized powder coating mixture.

[0038] 3) Rapidly cool the extruded material to room temperature and use a pulverizer to pulverize the cooled material to 20 - 100 μm to obtain a preliminary powder coating.

[0039] 4) Uniformly mix 2 parts of an antifoaming agent and the powder coating in a low-speed mixer at a rotation speed of 500 r / min for 10 minutes to further improve the processing and application performance of the powder coating and prepare a stable radiative cooling powder coating.

[0040] The radiative cooling coating is applied to the surface of the device housing, and the application method is electrostatic spraying. The coating of the radiative cooling coating is as Figure 1 shown. The left figure is before coating, and the right figure is after the coating. The lighting device is provided with a lighting device bulb 1, a device bracket 2, and an external housing 3 of the device. The coated area a after coating is as shown in the right figure. The back and heat dissipation fins 4 of the device are as Figure 2 shown. The left figure is after the coating; the right figure is before coating.

[0041] The preparation method of the thermal conductive material is as follows:

[0042] 1) The thermal conductive material is a thermal conductive gasket, which is made by mixing 40% RTV silicone rubber, 35% Si 3 N 4 , 3% toughening agent, and 2% catalyst;

[0043] 2) The prepared gasket is cut into a shape adapted to contact the power module and fixed between the power module and the device housing by pressing to ensure no gap in the heat transfer path.

[0044] The installation position of the thermal conductive material is as Figure 3 shown. The lighting device is provided with 3 internal power supplies 5, and corresponding thermal conductive materials 6 are arranged between the power supplies 5 and the housing 7. The physical diagram after the installation of the thermal conductive material is as Figure 4 shown.

[0045] Example 2

[0046] Example 2 is substantially the same as Example 1, except that the thermal conductive filler is BN.

[0047] Example 3

[0048] Example 3 is substantially the same as Example 1, except that the radiation functional filler is SiO 2 .

[0049] Example 4

[0050] Example 4 is substantially the same as Example 1, except that the reflection functional filler is ZnO,.

[0051] The refrigeration and heat dissipation performance of the above products was detected (the temperature of the external housing and the internal power supply after the LED lamp continuously works for 8 hours):

[0052] External housing temperature / °C Internal housing temperature / °C Internal power supply temperature / °C Example 1 60 70 67 Example 2 65 73 72 Example 3 66 75 69 Example 4 66 76 70

[0053] It can be seen from the above performance test results that the refrigeration and heat dissipation performance of Example 1 is the best.

[0054] Comparative Example 1

[0055] Comparative Example 1 is substantially the same as Example 1, except that only the thermal conductive material is used and the radiation refrigeration coating is not used.

[0056] Comparative Example 2

[0057] Comparative Example 2 is substantially the same as Example 1, except that the thermal conductive material is not used and only the radiation refrigeration coating is used.

[0058] Comparative Example 3

[0059] Comparative Example 3 is substantially the same as Example 1, except that the thermal conductive material is not used and the radiation refrigeration coating is not used.

[0060] The heat dissipation effect test is shown in the following table (the temperatures of the external housing and the internal power supply after the LED lamp continuously operates for 8 hours).

[0061]

[0062] It can be seen from the comparison of the above data that for high-power LED lighting devices, adopting the heat dissipation method described in the present invention has an obvious heat dissipation effect. At the same time, it can be seen that the temperature of the external housing of the lamp is significantly lower than the temperatures of the internal housing and the internal power supply, that is, the heat of the power supply and the heat inside the housing can be conducted to the external housing through the heat-conducting gasket and dissipated into the environment through the radiation cooling coating, verifying that the combination of the heat-conducting material and the radiation cooling coating described in the present invention can achieve better heat dissipation effect through the natural conduction, convection and radiation methods and by utilizing the synergistic effect of the radiation cooling coating and the internal heat-conducting material.

[0063] Comparative Example 4

[0064] Comparative Example 4 is substantially the same as Example 1, except that the number of heat dissipation fins installed on the high-power LED lighting device used during the test is reduced from 29 to 20.

[0065] Comparative Example 5

[0066] Comparative Example 5 is substantially the same as Example 1, except that the number of heat dissipation fins installed on the high-power LED lighting device used during the test is reduced from 29 to 10.

[0067] The heat dissipation effect test is shown in the following table (the temperatures of the external housing and the internal power supply after the LED lamp continuously operates for 8 hours).

[0068]

[0069] It can be seen from the comparison of the above data that for high-power LED lighting devices, adopting the heat dissipation method described in the present invention can achieve the same or even better heat dissipation and refrigeration performance while reducing the number of heat dissipation fins installed on the high-power LED device. It fully shows that the present invention can effectively reduce the number of heat dissipation fins installed on the device, and effectively reduce the production, transportation and installation costs of the device.

[0070] The method described in the present invention has a low dependence on the external environment. Even in an environment with high temperature or poor air flow, the radiation cooling coating can still efficiently radiate heat.

[0071] The above are only the preferred embodiments of the present application and are not used to limit the present application.

Claims

1. A heat dissipation method for lighting equipment, characterized in that: The heat generated when the power supply is working is conducted to the external frame of the lighting device through the thermal conductive material, and the heat is further radiated to the external air through the radiation cooling paint coated on the surface of the external frame, thereby greatly reducing the working temperature of the power supply; the thermal conductive material is a silicone-based thermal conductive gasket, which is mixed with a silicone rubber matrix, silicone oil, thermal conductive filler and other additives; the radiation cooling paint is prepared by mixing and dispersing a film-forming material with a radiation functional filler, a reflective functional filler and other additives.

2. The heat dissipation method of a lighting device according to claim 1, characterized in that: The silicone rubber matrix is ​​room temperature vulcanized silicone or thermosetting silicone.

3. The heat dissipation method of a lighting device according to claim 1, characterized in that: The thermal conductive filler is one or more of aluminum powder, copper powder, aluminum oxide, silicon nitride, graphite, and boron nitride.

4. The heat dissipation method of a lighting device according to claim 1, characterized in that: The other additives include toughening agents, crosslinking agents, and catalysts.

5. The heat dissipation method of a lighting device according to claim 1, characterized in that: The silicon-based thermally conductive pad is obtained by the following method: 1) First, 30-50 parts by weight of silicone rubber matrix, 30-40 parts by weight of thermal conductive filler, 1-5 parts by weight of toughening agent, 1-5 parts by weight of crosslinking agent, and 0.5-1 parts by weight of catalyst are placed in a high shear mixer, and mixed for 1-2 hours at a mixing speed of 500-800 r / min to obtain a uniformly mixed thermal conductive silicone rubber material; 2) Place the above-mentioned thermally conductive silicone rubber material into the template, ensure that all gaps are filled, and solidify and shape it under a certain pressure and temperature, then cool and demould, and process it into a certain shape.

6. The heat dissipation method of a lighting device according to claim 1, characterized in that: The film-forming substances include epoxy resin, silicone resin, acrylic resin, polyurethane resin and fluorocarbon resin.

7. The heat dissipation method of a lighting device according to claim 1, characterized in that: The radiation functional filler includes one or more of MgO, Al2O3, AlN, SiO2, and CaO.

8. The heat dissipation method of a lighting device according to claim 1, characterized in that: The reflective filler is one or more of TiO2, Y2O3, ZnO, MgF2, CaF2, copper powder, silver powder, and aluminum powder.

9. The heat dissipation method of a lighting device according to claim 1, characterized in that: The radiant cooling coating is obtained by the following method: 1) Mix 1-5 parts of dispersant and 20-50 parts of film-forming substance by weight, and mix them in a high-speed mixer at a speed of 800-1000 r / min for 10-15 minutes until the dispersant and the film-forming substance are evenly blended to form a basic mixture for powder coating; 2) adding 10-40 parts of reflective filler, 10-40 parts of radiative filler and 1-12 parts of wetting agent to the basic mixture, melt-extruding at 120-140° C. through an extruder, and using shear force to ensure uniform distribution of the components to obtain a functionalized powder coating mixture; 3) The extruded material is quickly cooled to room temperature, and the cooled material is crushed into a target particle size range using a crusher to obtain a preliminary powder coating; 4) 1-5 parts of the defoamer and the powder coating are uniformly mixed in a low-speed mixer at a speed of 300-500 r / min for 5-10 minutes to further improve the processing and application performance of the powder coating and prepare a radiant cooling powder coating with stable performance.

10. The heat dissipation method of a lighting device according to claim 1, characterized in that: The external frame includes an equipment shell and heat dissipation fins arranged on the equipment shell. The radiation cooling paint is applied to the outside of the equipment shell and its heat dissipation fins. The preferred coating method is electrostatic spraying.

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