为了提高LED灯具的散热能力, 基于烟囱效应原理, 设计了一种新型的LED灯具散热结构。该结构仅采用一块圆柱状基板, 不需要散热器, 突破了传统LED灯具的构造模式。运用软件Solidworks构建三维模型, 用其插件Flow Simulation进行热仿真。当功率为10 W时, LED芯片最高温度为81.34 ℃。当功率增加到15 W时, 最高温度变为105.54 ℃, 高于芯片安全工作温度85 ℃。因此, 本文提出在基板中间加入散热器的改进方案, 使LED芯片最高温度下降了30.79 ℃。并以散热器翅片数12个、内环直径20 mm、翅片厚度1 mm为基础模型参数, 进行优化试验。研究表明: 在翅片数为12个、内环直径为12 mm、翅片厚度为1 mm时, LED异形灯的散热效果最好, 此时, LED异形灯的最高温度为72.21 ℃。当功率为8, 13, 15, 17, 19 W时, LED异形灯芯片的温度都满足LED工作的安全要求。经过对8 W的LED异形灯样品的实验测试, 测得其最高温度为53 ℃, 与仿真结果仅相差1.01 ℃, 证实了研究的准确性。所设计的LED异形灯, 为解决大功率LED散热问题提供了一条新的途径。

In order to improve the cooling capacity of LED lamps and lanterns, a new type of LED lamp radiating structure was designed based on the principle of the chimney effect. The new type of LED lamp without radiator only used a cylindrical substrate break through the traditional mode of construction of LED lamps. A three-dimensional model was built by adopting Solidworks, and its plug called Flow Simulation was used to simulate the model. The highest temperature of LED chip is 81.34 ℃ when the power is 10 W. The highest temperature changes to 105.54 ℃ at 15 W, higher than the security temperature of LED chip. Therefore, an improved scheme of joining the radiator in the middle of the substrate was put forward. Then, the maximum temperature of LED chip reduces by 30.79 ℃. Based on the model in which the number of fins is 12, the diameter of inner ring is 20 mm, the thickness of fins is 1 mm, the thermal simulation was carried on. The results show that the special-shaped LED lamp has the best cooling capacity when the number of fins is 12, the diameter of inner ring is 12 mm, and the thickness of the fins is 1 mm. At the moment, the highest temperature is 72.21 ℃. The temperature of LED lamp can all meet the security requirements when the power of the special-shaped LED lamp is 8, 13, 15, 17 and 19 W. The experiment results of 8 W LED lamp show that the highest temperature is 53 ℃, higher than the results of the simulation results only 1.01 ℃. It confirms the correctness of the simulation. In conclusion, the designed special-shaped LED lamps provide a new way to solve the heat dissipation problem of high power LED.