LED投光灯叉翅散热器热分析及优化

Thermal Analysis of LED Floodlight Crossed-fin Heat Sink and Optimization

摘要:

为探究叉翅散热器在某100W LED舞台投光灯上的散热强化作用并进行优化设计,通过数值模拟与实验验证的方法,对影响叉翅散热器散热性能的主要几何因素及其机理进行了分析。以LED芯片最高温度和散热器质量为优化目标,对短翅长度与间距进行了单因素分析,然后通过NSGA-Ⅱ算法进行双目标优化,并进行模糊C均值聚类,得到了不同应用场景下散热器配置。结果表明:叉翅散热器可有效增强散热性能,其结构可增加翅片表面平均对流换热系数,短翅长度和间距对单位质量散热性能影响均存在最优值,短翅过长或间距过小均会使翅片表面对流换热系数下降。双目标优化后的叉翅散热器可在几乎不改变散热器质量时,降低LED芯片最高温度2.33℃。

Abstract:

To examine the enhanced heat dissipation effect of a crossed-fin heat sink on a 100W LED stage spotlight and optimize the design, we analyzed the main geometric factors and mechanisms that affect the heat dissipation performance of the heat sink. To this end, numerical simulation and experimental verification were performed. The optimization objectives were set as the highest temperature of the LED chip and mass of the heat sink. A single-factor analysis was performed on the length and spacing of the short fins, followed by a dual-objective optimization using the NSGA-Ⅱ algorithm. Fuzzy C-means clustering was then applied to obtain different heat sink configurations for different application scenarios. The results indicate that the crossed-fin heat sink effectively enhanced the heat dissipation performance by increasing the average convective heat transfer coefficient of the fin surface. Both the length and spacing of the short fins exhibited optimal values that influenced the heat dissipation performance per unit mass. With excessively long short fins or excessively small spacing, the convective heat transfer coefficient on the fin surface decreased. After dual-objective optimization, the crossed-fin heat sink reduced the highest temperature of the LED chip by 2.33℃ with almost no change in its mass.