基于LED灯具的散热考虑

　　基于LED灯具的散热考虑

　　由于使用LED照明灯具（称为灯具在照明业务）变得更加普遍，他们的设计师面临的LED矛盾。虽然LED比白炽灯泡效率高得多（图1），它们的最大允许工作温度要低得多，而且在工作温度限制下也很难保持。［注：可见光LED发光效率约为100流明/瓦，相比约15流明/瓦白炽灯。］在热强度的差异部分是由于玻璃，白炽灯泡的特种金属，陶瓷，固有可以容忍更多的热量比LED封装。

　　Figure 1： The luminous efficacy of LEDs （often informally confused with their efficiency） has increased dramatically over the years and is now five times to six times better than incandescent bulbs; ironically， the thermal issues and associated dissipation challenges are far more difficult for LEDs.

　　However， a large part of this difference is due to how the LED manages its own heat compared to a traditional bulb. Thermal physics shows that there are three ways for heat to travel from its source to a cooler sink：

　　Radiation， where the heat energy leaves as electromagnetic infrared waves. （Note that this is the only choice in the vacuum of space， making the cooling of spacecraft a real challenge.）

　　Conduction， where the heat travels through a solid or static liquid.

　　Convection， where the heat is carried away by a moving fluid （a gas， usually air， or a liquid in some advanced designs）.