Design And Optimization On Heat Radiation Of High-power LED Automotive Headlamp

Today, because of the increasing shortage of the energy, the new cold light source LED has greatly attracted people’s attention, for that it has the advantages of high efficiency, energy conservation, environmental protection and long service life, and so on. High-power LED as a lighting source not only can be very significant to save energy, but also can extend service life. With the continuous progress of science and technology, the improvement of LED luminous flux and heat dissipation problems have become a serious impediment to high-power LED lighting. And the two very critical issues have hindered the extension and popularization of high-power LED lighting. When the brightness of the chip has been increasing, at the same time, the temperature of the chip is also rising. And the high temperature will result in light fading, so that the life of LED lamps will be shortening or even losing its own effect. In the article, it is aimed at the problems that it is difficult to dissipate heat for high-power white LED automobile headlamps, and that even it will cause the issues of a decrease in brightness and reduction of service life. In order to solve these problems, the cooling device has been further researched and optimized the design for high-power white LED vehicle headlamps.In this paper, the air-cooled form and the Mean-temperature plate structure model has been applied to the cooling solution. The user-defined model is established by using ANSYS software. At first, in the natural convection state, measured the distribution of LED junction temperature at 25°C and 50 °C respectively. Secondly, after changing the convection coefficient, in forced convection state, observed the distribution of LED junction temperature at two different temperatures. By comparison, it is found that cooling effect is better in forced convection state whatever temperature the headlamp is working at. So, in the follow-up work, select the forced convection method, and the ambient temperature are set to 50 ° C. Through quantitative calculation, change the number of fins, the thickness of heat sink and the aluminum plate, and the height of fins, and observe the LED junction temperature distribution in a variety of conditions. Then, the optimal design results of the Mean-temperature plate structure model will be got by comprehensive Analysis. In the case of optimum design, it is measured that the maximum temperature of model is about 64 ° C. Compared with the previous 70 ° C before optimizing, it reduce 6° C. Improve the cooling effect, at the same time, also meet the high power LED headlamp cooling requirementsThe cooling solution by this article discussed, compared with the conventional, without changing the lamp chamber space and the stability of the premise, it is possible for further use of the light cavity headlamps factor structure itself, and some conditions when the car is moving, timely and effectively, to dissipate the heat generated by the LED, and then the LED’s operating temperature can be quickly reduced. Thereby, it ensures that the vehicle headlamp can work stably. This not only reduces the cost of car headlights, but also the structure of the headlamps is relatively simple. It has a very important significance and value for the automotive industry which uses high-power LED as a vehicle headlamp lighting.