论文部分内容阅读
将瞬态团簇尺寸分布模型引入蒸汽冷凝体系,通过求解描述团簇增长的动力学方程,模拟研究了特定冷凝条件下团簇及微小液滴尺寸分布的演化特征。模型结果表明,核化过程中,团簇/微液滴尺寸分布迅速从单调递减式分布转变为近似正态分布特征。随着时间延长,尺寸分布的峰值向团簇/微液滴尺寸增加的方向移动。在壁面冷凝过程中,核化生成的最小液滴也具有一定分布,进一步完善了经典冷凝理论中对初始冷凝过程液滴分布和演化过程的描述。同时模拟结果与文献报道的微米级液滴生长演化趋势相似,表明较大尺寸液滴分布特征是核化阶段团簇/微液滴尺寸分布特征进一步演化的结果,揭示了冷凝过程液滴尺寸分布演化的微观物理本质。
The transient cluster size distribution model was introduced into the steam condensing system. By solving the kinetic equation describing the growth of the clusters, the evolution characteristics of the size distribution of the clusters and tiny droplets under a specific condensation condition were simulated. The model results show that during the nucleation process, the size distribution of the clusters / microdroplets rapidly changes from a monotonically decreasing distribution to an approximately normal distribution. As time goes by, the peak of the size distribution moves in the direction of increasing cluster / droplet size. In the process of wall condensation, the minimum droplets generated by nucleation also have certain distribution, which further improves the description of the droplet distribution and evolution in the initial condensation process in the classical condensation theory. At the same time, the simulation results are similar to those reported in the literature. The results show that the distribution characteristics of larger droplets are the result of the further evolution of the size distribution of clusters / microdroplets in the nucleation stage, revealing the droplet size distribution The micro-physical nature of evolution.