Providing an enormous heat transfer, droplet boiling evaporation is widely used in the liquid cooling for nucleate reactors and high-power electronic devices and other fields. This paper reported a combined theoretical and experimental study on the evaporation characteristics of the droplets attached to a high temperature wall (>100°C). Different from the non-boiling evaporation, the effect of droplet temperature on evaporation time, contact angle and evaporation process are investigated. Nucleate boiling regime in the evaporation of a single droplet, especially the transition from static evaporation to nucleate boiling is investigated. Our results report that the evaporation of sessile droplets in boiling regime is very intense, and can be classified into five stages according to the change in internal bubble morphology, namely the wall bubble germination, wall bubble growth, global bubble germination, global bubble growth, and central large bubble formation. Droplet evaporation does not follow the constant contact diameter pattern in the non-boiling regime, but consists of growth period, steady period, and decline period. Basically consistent with the experimental results, the feasibility of numerical simulation to study the droplet evaporation in the boiling regime is verified.

液滴沸腾蒸发提供巨大的传热，广泛应用于成核反应堆和大功率电子设备的液体冷却等领域。本文报道了对附着在高温壁（> 100°C）上的液滴的蒸发特性的综合理论和实验研究。与非沸腾蒸发不同，研究了液滴温度对蒸发时间、接触角和蒸发过程的影响。研究了单个液滴蒸发中的核沸腾状态，特别是从静态蒸发到核沸腾的转变。我们的结果报告说，沸腾状态下固着液滴的蒸发非常强烈，根据内部气泡形态的变化可以分为五个阶段，即壁面气泡萌发、壁面气泡生长、全局气泡萌发、全局气泡生长和中心大气泡形成。在非沸腾状态下，液滴蒸发不遵循恒定接触直径模式，而是由生长期、稳定期和下降期组成。与实验结果基本一致，验证了数值模拟研究沸腾状态下液滴蒸发的可行性。