LED结温高一直是大功率LED发展的技术瓶颈,随着单位热流密度的不断攀升,在自然冷却条件下,单纯的直肋热沉散热方式已不能满足散热要求.应用热管技术设计了热管散热系统,对该系统的传热机理和传热路线进行分析,建立该系统对应的热网络模型,对各部分热阻进行分析与计算,求得总的理论总热阻,计算得出理论结温；同时应用有限元方法对该系统进行仿真分析,对LED模块(0.025 m×0.025 m×0.005 m)输入30 W电功率,得出其仿真结温稳定在58.19℃,满足结温小于65℃的要求,说明应用热管的散热系统满足设计要求.由热阻网络模型计算得出的理论结温为57.43℃,与仿真结果相差0.76℃,其误差仅为1.31％,验证了理论分析计算的正确性,对实际工程中热设计具有指导意义.%High junction temperature of LED has been the technical bottleneck of the development of high power LED. With the rising of heat flux density, the simple straight fin heat sink can not meet the requirement of heat dissipation in natural cooling conditions. We set up a heat dissipation system based on the heat-pipe technology, analyzed the heat transfer mechanism and the route of heat dissipation , then established the model of thermal network according to the physical model and calculated the thermal resistance of each part, finally got the total theoretical thermal resistance and the LED junction temperature. At the same time, we made a simulation analysis of this heat dissipation system by using the finite element method. Simulation results of the LED module(0. 025 m×0. 025 m×0. 005 m) with 30 W input power show that the junction temperature of LED stable is at 58. 19℃ , less than 65℃ which is the deadline of requirement. The cooling system applying the heat pipe meets the requirement of design well. The theoretical junction temperature calculated by thermal model is 57. 43℃ ,only 0. 76℃ less than the simulation result, implying the error is only 1, 31 %,this validates the theoretical analysis calculation , which has guiding significance for practical engineering design.
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