过饱和蒸汽非平衡态等离子体诱导凝结过程机理研究

In the researches of phase-change heat exchangers, aerosol formation and nano material preparation etc., the process of molecular condensation induced by charge has been paid more and more attention. Recently, some studies have been proposed that the a part of the latent heat can be converted into electrical energy by means of plasma induced supersaturated vapor condensation. However, in the above research fields, the induction mechanism of condensation of a variety of charged particles and processes in non-equilibrium plasma has not been proved. In this research project, a variety of charged particles and processes will be introduced into the molecular dynamics simulations of supersaturated steam non-equilibrium plasma. At the same time, the influence of the macroscopic parameters of non-equilibrium plasma on the micro condensation process is considered. The induced law of condensation is induced According to the simulation results. It is expected that the induction mechanism of steam molecular by non-equilibrium plasma will be revealed. The macroscopic fluid and heat transfer model of supersaturated steam with non-equilibrium plasma induced condensation will be established. The study of this project will provide theoretical foundation for engineering application of induced condensation.

在相变换热、气溶胶形成、纳米材料制备等研究中，电荷诱导分子凝结已得到越来越多的关注。最近亦有研究提出利用等离子体诱导过饱和蒸汽凝结，将部分汽化潜热转化为电能输出。但是以上研究领域中，非平衡态等离子体多种荷电粒子和过程共同作用诱导凝结机理尚未探明。本项目将开展,过饱和蒸汽中加入非平衡态等离子体多种荷电粒子和过程的分子动力学模拟研究，同时考虑非平衡态等离子体宏观参数对于微观凝结过程的动态影响。根据模拟结果，归纳诱导凝结规律。本项目预期揭示非平衡态等离子体诱导凝结机理。建立含有非平衡态等离子体诱导凝结的饱和蒸汽宏观流体和传热分析模型。本课题的研究为诱导凝结的工程应用提供理论基础。

等离子体诱导水分子凝聚现象有着广泛的应用。最新实验中产生电荷的方法都是典型的非平衡态等离子体放电，如电晕放电。但是该过程尺度极小，反应复杂，极难通过实验来直接观测。迄今为止，带电粒子的形成和增强凝聚的机理尚未完全阐明。本课题围绕非平衡态等离子体放电机理和等离子体诱导凝结的宏观微观机理展开研究。主要进展包括以下三个方面。1、在非平衡态等离子体放电的流体模型上，推导了荷电粒子与中性分子碰撞造成的能量与动量传递项，构建传热传质数学模型。2、完善了水蒸气非平衡态电晕放电机理，改进了电荷增强凝结成核模型，首次将非平衡态等离子体数值模拟与非均相成核模型相结合。从而可以研究宏观非平衡态等离子体放电参数对微观凝结过程影响规律。该模型和结果有助于理解非平衡态等离子体增强凝聚的机理。3、对非平衡态等离子体诱导凝结过程的微观机理分析。其结果指出水分子作为极性分子，由于荷电粒子电场影响，会以荷电粒子为核心发生偏转和聚集，形成最初的凝结核心，从而强化凝结过程。本课题研究成果深化了对等离子体诱导蒸汽分子凝结过程的理论认识，为进一步应用提供理论基础。