Thermal model design and analysis of the high-power LED automotive headlight cooling device

Abstract

A study of the thermal performance of conventional plate-fin heat sinks and novel cooling device integrated with heat conductive plates (HCPS) for the application in high-power LED headlight was presented. The thermal resistance network model was built to analyze the factors which have impacts on the junction temperature. The analyses were based on the experiment combined with computations using the CFD software FloEFD. The prediction results were validated with the experimental one. Details of the heat transfer performance, particularly the temperature distribution of the LED module and lampshell, as well as the effect of HCPS length on the system thermal resistance and the average heat transfer coefficient were obtained. Since it could make some distance between the heat sink and the lampshell, the average surface convective heat transfer coefficient had been improved and the overall external thermal resistance was reduced effectively. The effects of the simulated ambient temperature, chip package depth, inclination angles and fan rotate speeds on the junction temperature were also examined. Results indicated that the airflow was weakened as the chip package depth increased. In addition, with the presence of the enforced velocity airflow, the junction temperature decreased gradually from 116.61 °C to 78.05 °C.