Research On Heat Transfer Performance Optimization Of Intelligent Car Headlight

In recent years,LED automotive headlights have gradually replaced halogen headlights and hernia headlights with their features of long life,high efficiency and low energy consumption,and are widely used in the field of automotive headlights.But its heat dissipation problem constrains the development of high-power LED car lamp industry.The research shows that the heat dissipation performance of LED car lights is mainly related to the heat dissipation mode and the material of LED car lights PCB board.Therefore,this paper takes the high-power LED headlamp of Guangxi Liuzhou Wuling Automobile as the research object,combines the knowledge of heat transfer,fluid mechanics and other disciplines,and studies its heat dissipation by means of finite element analysis and experimental verification.In order to analyze the influence of LED lamp heat dissipation mode and PCB material on its heat dissipation performance,this paper uses UG software to establish a threedimensional LED lamp model,and uses Fluent software to establish a three-dimensional LED lamp heat generation model and fluid dynamics model.This paper analyzes the heat dissipation performance of LED car lamps made of MMC,MPCBs,Cu and Al.The results show that the heat dissipation performance of LED car lamps made of MMC,MPCBs,Cu and Al is in the order of Cu,MMC,Al and MPCBs under the same ambient temperature.On this basis,the influence of ambient temperature and lamp power on the thermal conductivity of copper substrate and aluminum substrate is also analyzed.The results show that the best cooling effect is obtained by using copper as the substrate.Based on the cost factor,the natural convection heat transfer model of LED car lamp with finned radiator is established in this paper.The affect of the number of fins on the heat dissipation performance of the car lamp is analyzed.The ambient temperature is set as 30℃and the bulb power is set as 36 W.The simulation results show that the change of the number of heat sinks has little effect on the heat dissipation of the headlamp under the condition that the size of the heat sinks remains unchanged.When the fin number is 5 and 8,the maximum temperature of the headlamp is 120.05℃ and 118.2℃,respectively.On the basis of simulation,the experimental verification shows that the maximum temperature of the lamp is 118.7℃,which is about 2℃ different from the simulation results.The model has high accuracy.However,the working temperature of the lamp cannot exceed 80℃,so the heat dissipation method does not meet the requirements.The cost factor should be ignored and the heat dissipation method should be optimized.For installation of finned radiator of the LED lamp light the problem of high temperature natural convection heat transfer model,this text established the finned radiator installation LED lights forced convection heat transfer model,the lamp add water cooling device,analyzes the impassability airflow effect on the properties of light heat radiator,comprehensive consider light stability,the power factor and the heat dissipation effect,The air volume was selected as 4 CFM.The simulation results show that,compared with the natural convection heat transfer model of the headlamp with fins,the maximum temperature of the headlamp is reduced to 69.584℃,which is reduced by about 51℃,and the heat dissipation effect is obvious.This heat dissipation method meets the requirements.Above is not installed to the car LED lights,heat transfer analysis,considering the practical engineering application,the lamp to the car equivalent to bring lights have a shell,therefore,this paper established the installation of fin heat sink and the shell of the LED lamp forced convection heat transfer model,air volume for 4 CFM,lights the highest temperature of 75.7 ℃.This temperature is close to the limit of lamp working temperature,barely meet the requirements.In order to ensure that the lamp has sufficient space for temperature rise,graphene material is added into the heat dissipation material in this paper.Through simulation,the temperature is reduced by about 10 ℃.This optimization method can effectively improve the life and reliability of the lamp.Finally,this paper designed the LED temperature test experiment,according to the characteristics of the LED actual working environment,simulate the ambient temperature,determine the vehicle lamp heat dissipation experiment collection,the type of temperature system,etc.,to build an experimental platform.The conclusion shows that the absolute error between the simulated temperature and the measured temperature is less than 10%,and part of the error is related to the simplified headlamp model,which verifies the accuracy of the simulation.Therefore,the heat transfer model established in this paper can accurately analyze the heat dissipation characteristics of LED headlights,which can provide reliable reference value for engineering applications.