海绵钛还原过程TiCl4非平衡相变规律及相变流场特性研究

The theory of heat and mass transfer, metallurgy transport and energy transfer of the flow were seriously lagged behind, matured to insufficient theoretical understanding of the titanium reduction system, obtained to the indeterminacy of mechanisms about titanium tetrachloride(TiCl4) in reduction reactor in Kroll process. By taking the non-equilibrium phase transition of TiCl4 in reduction reactor as the research object, basing on thermodynamics calculation and experiments about phase transition, the thermodynamics and dynamical model about non-equilibrium surface boiling of TiCl4 are established. And the phase transformation laws are expounded. Then, the heat and mass transfer models of surface boiling are established based on the experiments of numerical simulation and verification. And the flow characteristics of surface boiling process are expounded. Further more, the mechanisms of phase transition would be exploratory studied. The results would provide basic theory support for intensification of heat transfer and mass transfer in titanium sponge reduction process. Implementation of this project will be of guiding significance to production efficiency enhancement, energy conservation and consumption reduction in titanium sponge industry in China.

镁热法生产海绵钛还原过程TiCl4相变行为不明确造成对还原系统的理论认识不足，冶金传输、流场传热与流动理论研究滞后。以还原过程TiCl4表面沸腾相变过程为研究对象，根据TiCl4平衡相变过程的热力学计算和TiCl4相变物理试验建立TiCl4表面沸腾非平衡相变热力学和动力学模型，阐明TiCl4表面沸腾非平衡相变规律；以TiCl4相变物理试验和数值模拟试验为基础，建立TiCl4表面沸腾相变过程的传热与流动模型，对TiCl4表面沸腾相变形成的气-熔流场进行数值计算，阐明TiCl4表面沸腾相变流场特性；揭示TiCl4表面沸腾非平衡相变过程机理，为强化海绵钛还原过程流场的传热与传质技术提供基础理论支撑。该项目的实施对我国海绵钛行业的生产效率提高及节能降耗具有重要的指导意义。

镁热法生产海绵钛还原过程TiCl4相变行为不明确造成对还原系统的理论认识不足，冶金传输、流场传热与流动理论研究滞后。本项目分析不同壁面过热度下液态TiCl4沸腾传热曲线和沸腾传热系数的变化规律，并确定了液态TiCl4沸腾传热Rohsenow关联式中的两个实验常数Cw=9.62×10-3，s=1.89，得到了液态TiCl4沸腾传热Rohsenow经典关联式；利用量纲分析法，拟合得到了液态TiCl4沸腾传热Nu数的实验关联式。建立了一个内部平衡、外部不平衡的非平衡热力学系，基于“界面相”的概念，推导了液态TiCl4沸腾相变过程界面熵产的计算公式，研究了比熵产和界面温度的不连续性的变化规律；确定了界面熵产最小化的热力学条件。基于立方型状态方程Peng-Robinson模型（简称“P-R EOS模型”），建立了混合气体xTiCl4+(1-x)Ar二元系的p-v-T模型，研究了超临界温度下气相TiCl4+氩气混合气体的p-v-T关系，基于氩气的立方型状态方程的P-R EOS模型计算得到了气相TiCl4的p-v-T关系和气相TiCl4的P-R型状态方程；计算了气相TiCl4的压缩因子和Virial型状态方程。基于格子Boltzman方法构建了液态TiCl4非平衡沸腾相变模型，研究了不同条件下液态TiCl4非平衡相变的流场特性。.在项目资助下，共完成发表SCI学术论文6篇，授权国家发明专利3项。培养毕业博士研究生1名，毕业硕士研究生3名。