混合工质溶液池沸腾气泡成核及换热机理研究

项目名称： 混合工质溶液池沸腾气泡成核及换热机理研究

项目编号： No.51506057

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 能源与动力工程

项目作者： 许雄文

作者单位： 华南理工大学

项目金额： 20万元

中文摘要： 非共沸混合工质相变传热广泛存在于能源化工流程中，目前其传热关联式对于较大温度滑移下的混合工质适用性较差，给换热器设计计算带来了很大的制约。本项目以非共沸混合工质溶液沸腾过程为研究对象，对其沸腾过程中的气泡成核衰减机理及沸腾换热衰减规律进行基础科学研究。主要研究内容有：从分子运动学出发，提出混合工质沸腾气核密度衰减机理，并建立混合工质气核密度的数学模型，计算混合工质相比纯工质时的气核衰减系数，修正沸腾气核衰减后的混合工质沸腾传热关联式；采用传质主导模型计算气液界面上的有效过热度，考虑传质阻力引起的传热衰减；从而建立同时考虑沸腾气核衰减及气泡成长传质阻力作用后的沸腾传热关联式并进行实验验证。本项目旨在揭示混合工质成核机理，通过混合工质溶液沸腾气核密度衰减系数修正其沸腾传热关联式，得到一个适用性较强的混合工质沸腾传热计算关联式。

中文关键词： 相变传热机理；气泡动力学；气泡生长

英文摘要： The phase change heat transfer of non-zeotropic mixture solution widely exists in the energy chemical processes. At present, the heat transfer correlations are poorly applicable to mixture solutions with large temperature glide, which made greatly trouble to the heat exchanger design. This study takes the boiling process of non-zeotropic mixture solution as object, focus on fundamental mechanism research of the gas nucleus reduction and the boiling heat transfer decrement. A theory of mixture solution boiling nucleation will be tried to propose through the molecule dynamics. The mathematical model of the nucleus density will be constructed to calculate the reduction ratio by the mixed effect. Then the boiling heat transfer correlations deriving from the pure substances will be corrected by considering the nucleus reduction in mixture solutions. After that, considering the heat transfer reduction by mass transfer resistance, the effective superheated degree on the interfacial of the gas and liquid will be calculated through the mass transfer dominating model. At last, a new boiling heat transfer correlation of non-zeotropic mixture solution will be constructed and verified by experiments. This study aims at disclosing the boiling gas nucleation mechanism of mixture solutions, and obtaining a more adaptive pool boiling heat transfer correlation for mixture solutions.

英文关键词： Phase and heat transfer mechanism;Bubble dynamics;Bubble growth