微热管式汽车LED大灯的设计与散热研究

Design and Heat Dissipation Research of Micro Heat Pipe Automobile LED Headlamp

在密闭狭小空间,散热问题是制约大功率LED在汽车大灯领域发展的因素之一。提出了一种用于汽车LED大灯的以铜粉为烧结芯的平板微热管组散热装置,针对车灯运行的不同工况,研究了热阻、环境温度及翅片组上的对流换热系数等参数对散热器性能的影响,最后进行了微热管车灯散热实验。结果表明:正常工作环境下,当LED灯的功率为60 W时,LED结点温度为67℃,散热器的热阻稳定在0.61K/W;复杂环境和高功率工况下,LED结点温度都低于120℃,在翅片上的对流换热系数大于80W/(m2·K)后,LED结点温度趋于平稳。同时,实验验证了散热器的性能,在输出功率为50W的情况下,热管式散热器LED结点温度为58℃,说明该新型热管式散热器能满足汽车LED大灯散热的要求。

In the confined space, heat dissipation problem is one of the factors that restrict the development of high power LED in automotive headlamps. A flat panel micro heat pipe group with copper powder as sinter core, is proposed as a radiator used in automobile LED headlamp. Under different working conditions of vehicle lights, the effects on the radiator performance of thermal resistance, ambient temperature, and convective heat transfer coefficient of the fin group are studied. Finally, the heat dissipation experiment of the micro heat pipe for vehicle light is conducted. The results show that, under normal working conditions, when the power of the LED lamp is 60 W, the junction temperature of the LED is 67 ＊C, and the thermal resistance of the radiator is stable at 0.61 K/W. Under complex and high power conditions, the junction temperature of LED is below 120 ℃, and when the convective heat transfer coefficient of the fin is greater than 80 W/（m2·K）, the junction temperature of LED tends to be stable. Meanwhile, the performance of the radiator is verified by experiments. When the output power is 50 W, the LED junction temperature of the heat pipe radiator is 58 ℃, indicating that the new heat pipe radiator can meet the heat dissipation requirements of the LED headlamps.