Design And Research Of Heat Dissipation Device For Automobile LED Headlamp Based On Heat Pipe

In recent years,light-emitting diodes(LED)are gradually becoming the light source of our new era,more and more widely used in the automotive field,and will soon become the main light source of automobiles in the new era.However,the development of automotive LED headlamps is restricted to a great extent because of the large power and high heat flux of headlamps.At the same time,the amount of excess heat that is not released in time will also affect the service life of LED.How to solve the problem of heat dissipation in automotive headlamp lighting for high-power LED has been restricting the development of high-power LED headlamp.Aiming at the heat dissipation problem of LED headlamps,the following research and design are carried out in this paper.Firstly,this paper analyzes and compares various heat dissipation methods and heat dissipation structure,and collects the current development status of LED.SolidWorks software is used to design headlamps for automobiles with high-power LED as the light source.Each headlamp is equipped with three different heat sinks based on heat pipe technology,which are micro-heat pipe radiator,flat micro-heat pipe radiator and pulsating heat pipe radiator.The three kinds of radiators are simple in structure and can be produced to meet the current car halogen headlamps to LED headlights refit.Secondly,the typical micro-heat pipe LED headlamp radiator model is imported into ANSYS workbench finite element analysis software,and the simulation data of the end temperature and the end temperature of the radiator are derived through the chip in the temperature field.Through theoretical qualitative analysis,it calculates whether the micro heat pipe radiator meets the large probability of heat dissipation of LED headlamps.At the same time,it can meet the economic,energy saving and environmental protection performance of the radiator.The effects of thermal resistance,ambient temperature and convective heat transfer coefficient on the performance of radiator were studied for different working conditions of vehicle lamp.The heat dissipation experiment of micro-heat pipe lamp was carried out.The results show that under normal working conditions,when the power of LED lamp is 60W,the temperature of LED node is67℃,and the thermal resistance of radiator is stable at 0.61K/W.When the temperature of LED node is lower than 120℃,and the convective heat transfer coefficient on the fin is greater than 80W/m~2·K,the temperature of LED node tends to be stable.Finally,we verify the feasibility of the automobile LED headlight micro heat pipe radiator by experiments.By building an experimental platform.The node temperature and radiator terminal temperature were measured.The results show that the node temperature of the micro-heat pipe radiator is 60℃and the terminal temperature is30℃at the power of 50 W.The start-up time of the micro heat pipe is 3min.Then,three different medium acetone,ethanol and distilled water were tested on the heat transfer performance of the heat pipe.The experimental results show that acetone is the best and the lowest node temperature is 52℃.The filling rate is between 30 and40%,which is the best liquid filling rate.Through the simulation and verification test in this paper,it is concluded that the heat pipe technology based on automotive LED headlamp is a good exploration direction,to a certain extent,effectively reduce the node temperature of LED headlamp.The heat dissipation efficiency of LED has been enhanced,and the service life of LED headlamps has been enhanced.It also shows that the new type of heat pipe radiator can meet the heat dissipation requirements of LED headlamps.