Design And Optimization Of Three-dimensional Phase Change Heat Sink For High-power LED

LED(Light Emitting Diode),the fourth-generation lighting source,has the advantages of small size,low power consumption,long service life,and environmental protection.Theoretically,it can replace the traditional energy-saving lamps and incandescent lamps to solve the energy shortage problem.However,heat dissipation is a big problem with the practical applications of LED which hamper the complete replacement of traditional lighting products.Study on the main reasons for limiting the LED into the general lighting market was carried out in this paper.The results indicated that the LED luminous efficiency is low,about 20% to 30%,and most of the energy is converted into heat energy.With the increase of LED operating time,junction temperature of LED continues to rise,which is more likely to have negative effects such as light bias,low life,low luminous efficiency.Thus,effective thermal management of LED becomes the best way to accelerate LED into the general lighting market.Analysis on experiment and simulation are used to correlate LED heat production,and a high-power LED three-dimensional phase change heat sink is designed.The innovations and main contents of this paper are as follows:1.Innovation point of this paperIn this paper,the innovations were mainly divided into three parts.Part one,the phase transition technology was applied to the LED heat sink,and it is proved that the application of phase change technology in the heat dissipation process can reduce the thermal resistance in the transmission process.Part two,based on the phase change technology,a three-dimensional phase-change heat sink with a simple principle and low cost is designed by using the principle of gravity heat pipe,and it is applicable to general high-power LED lamps in the current market.Part three,a theoretical basis is provided for structural optimization of three-dimensional phase change heat sinks.2.LED heat production analysisAccording to the different heat flux characteristics of high-power array LEDs and high-power integrated LED lamps,numerical simulation and experimental methods were used to investigate respectively.It can be concluded that 1)the use of heat sinks can significantly reduce the junction temperature of LEDs,and the LED junction temperature increases with heat.As the height of the sinker increases,it gradually decreases.2)As the height of the heat sink increases,the effect of reducing the junction temperature decreases.However,the quality and cost of the heat sink increase linearly with the increase in the heat sink height.Therefore,the actual height of the heat sink is not the higher in the actual design and production process.3.Design and optimization for three-dimensional phase change heat sink of highpower LEDBased on the above conclusions,a high-power LED three-dimensional phase change heat sink was designed in this paper.The designed three-dimensional phase change heat sink is studied through numerical simulation.The results show that the phase change heat sink has obvious advantages over the traditional solid heat sink,and the advantage is more significant with the increase of LED power.Further quantitative analysis of factors affecting the heat transfer effect: heat sink material,heat sink heat dissipation area,and air convection heat transfer coefficient.The results show that in the production process of LED heat sinks,the heat sink heat dissipation area and the air convection heat transfer coefficient to the heat sink heat The effect of resistance is more pronounced,while heat sink materials can be selected for materials that are less expensive.