The Optimal Design Of Heat-removal System In Car’s LED Headlight

LED is considered as the4th generation light source in our history. Since low-carbon lifestyle and environmental protection theme came to our every-day’s life, LED illumination technology is getting people’s attention. LED lighting system used in automobiles has displayed a significant advantage, it is environmentally friendly and energy-efficient, its color temperature is better than other lighting systems, and also, the LED chip is so small that can be designed in various shape or style, and so on. However, because of the way of shining, when it is working, the heat generated in chip cannot be disseminated effectively, so heat dissipation problem is the stumbling block to LED’s development.This research topic comes from project of New Electric-vehicle Design With Digital Simulation Technology, which is a new design of pure electric vehicles using full digital modeling and simulation technology. We have customized a LED headlight system for this new electric-car, and my main task is to optimize LED’s cooling system. The key continent of this paper is how to solve the problem of LED’s thermal dissipation.First of all, we have identified the program based on previous research theories. Our approach to solving the problem is that:by changing the geometry of the heat-sink to improve the efficiency of its heat dissipation, and use LED chip junction temperature calculated by CAE software to express the radiation efficiency.Secondly, through learning the heat transfer theory and the hydromechanics elementary knowledge, we established a heat transfer model and a parameterized physical model. By changing each parameter of the physical model, a series of topological model will come out. What is more, we can study each parameter’s impact on the thermal efficiency of cooling system, through which we can confirm the best value of this parameter. Then, we take these model into simulation by using software of Icepak, which is a professional CAE software. In the process of our simulations, we took two conditions into consideration, one is when the car is static, the other is when the car is running at the speed of60km/h. By studying the influence of the parameters on the cooling effect, we can determine the value of each parameter.Finally, we conduct an experiment to verify the performance of our final structure. We calculated the efficiency of heat removal, reached the efficiency of88%. We also checked its vibration performance, as we expected, it met the design requirements. After calculated every parameter’s value, we made the heat-sink and measured the temperature change when LED is working. According to the result, we conclude that the capacity of LED headlight has been improved, and the cooling system has been optimized.