论文部分内容阅读
通过纳米颗粒沉积法在不锈钢球上制备了静态接触角大于160°的超疏水表面,并采用淬火法对该不锈钢球在过冷度为0℃~25℃的去离子水中的瞬态池沸腾传热过程进行了实验研究。结果表明,由于表面的超疏水特性,整个瞬态沸腾过程直至极低表面过热度时始终处于膜态沸腾状态。不锈钢球的冷却速率随着过冷度的增大而提高,其膜态沸腾的热流密度和平均努塞尔数也随着过冷度的增加而近似呈线性增长的趋势。对汽膜演化过程的可视化观察发现,在过冷度较大时蒸汽产生量减少,导致汽膜层扰动减弱、汽液相界面趋于平稳。
The superhydrophobic surface with the static contact angle greater than 160 ° was prepared on the stainless steel ball by nanoparticle deposition. The transient pool boiling of the stainless steel ball in deionized water with supercooling of 0 ℃ ~ 25 ℃ The thermal process was studied experimentally. The results show that due to superhydrophobic properties of the surface, the entire transient boiling process is always in membrane boiling until very low superficial superheat. The cooling rate of stainless steel balls increases with the increase of undercooling, and the heat flux density and average Nusselt number of film boiling increase approximately linearly with the increase of undercooling. The visual observation of the vapor evolution process shows that the steam generation decreases when the supercooling degree is large, which leads to the weakening of the vapor layer disturbance and the steady-state vapor-liquid interface.