크레비스형 베이퍼 챔버를 가진 히트파이프를 이용한 자동차용 LED 헤드램프의 냉각 시스템 개발

Abstract

The Light Emitting Diode(LED) receives attention to headlamp of vehicle because of reduction of using energy and cutting down on CO2 emissions. Above all, it has long life span as 10,000 hours comparing halogen, and uses low electricity. This is effective for improvement of fuel consumption and it'll helpful for an electromobile. And it has quick response and durability. Also, it is eco-friendly due to not using mercury gas. Furthermore, it can be compact and light-weight. However, it has a considerable disadvantage to use LED for headlamp. It is that the LED generate high heat from modules and the heat may cause failures in electronics. We thought that research is needed to solve the problem and studied the method to radiate the high heat quickly. Therefore, the purpose of this study puts to develop the cooling system of LED headlamp for vehicle using crevice type vapor chamber heat pipe and to analyze thermal properties of a LED headlamp cooling system. Working fluid was distilled water and Al2O3 nanofluids, its charging ratio differed according to test conditions. We also considered sintered on heating surface to improve cooling performance. As a result of the experiments, when the charging ratio is 55 %vol., the LED Chip temperature was 72.05℃ and the thermal resistance was 2.2 ℃/W to search optimum charging ratio of crevice type vapor chamber. And, in the case of sinter, 30 %vol. of vapor chamber volume showed the best performance among all experiments. At that time, the LED chip temperature was 70.35℃ and the thermal resistance was 2.33 ℃/W. Also, when we use Al2O3 nanofluids, the LED Chip temperature was 78.25℃ and the thermal resistance was 2.56 ℃/W. In this study, we knew that LED chip temperature was maintained below 85℃ in all test conditions and and the crevice type vapor chamber heat pipe has possibility for use LED headlamp cooling system.