船用LNG燃料点火与火焰传播机制研究

项目名称： 船用LNG燃料点火与火焰传播机制研究

项目编号： No.51509198

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 其他

项目作者： 张尊华

作者单位： 武汉理工大学

项目金额： 21万元

中文摘要： 船用LNG燃料是一种典型的多组分燃料，其基础燃烧特性并非各单一燃料的简单线性叠加，深入研究其点火与火焰传播机制对LNG燃料在船舶动力装置中的推广应用具有重要指导意义。本项目将利用定容燃烧弹高速纹影摄像系统和点火能量实时测控装置，准确获取船用LNG燃料向外传播球形火焰的基础燃烧实验数据，阐明质量和热量间的非对等扩散、点火能量和燃料组分对LNG点火及火焰传播特性影响的内在规律。在此基础上利用实验数据验证并完善LNG燃料燃烧反应动力学机理，构建基于详细化学机理的火焰动力学与点火热力学耦合的LNG点火与火焰传播理论计算模型，以此研究球形火焰前锋面分子水平的动态精细化结构，探索火核的形成、发展与火焰传播等演变过程和规律，揭示船用LNG多组分燃料的点火与预混火焰传播机制。该研究可为船用LNG发动机点火系统的优化设计以及LNG燃料安全、高效和清洁燃烧提供重要基础数据和一定理论支撑。

中文关键词： 船用LNG燃料；点火能量；火核形成；火焰传播；化学动力学

英文摘要： Marine LNG fuel is a typical multicomponent fuel, and its fundamental combustion characteristics cannot be derived accurately from the linear combination of the combustion characteristics of each component involved in LNG fuel. To conduct a thorough study on the mechanism of ignition and flame propagation of LNG fuel is of great significance for the wide application of LNG fuel to marine power plants. In the present project, the experimental data for the outwardly expanding spherical flames of LNG fuel will be determined accurately using an experimental facility for spherical flames, which mainly consists of a constant-volume combustion bomb and a schlieren optical system, and a real-time measurement and control device for the ignition energy. The effects of the non-equidiffusion between mass and heat, the ignition energy and the fuel composition on ignition and flame propagation of LNG fuel will be investigated. Subsequently, the reaction mechanism for LNG combustion will be validated and improved in terms with the experimental data obtained, and then a theoretical model for ignition and spherical flame propagation of LNG fuel will be built. In this theoretical model, the coupling between the ignition thermodynamics and the flame dynamics based on detailed chemical kinetics is taken into consideration. By means of the theoretical model, the dynamic structure of the spherical flame front at molecular level will be investigated, and the evolution laws of some typical processes such as the formation and development of the flame kernel and the spherical flame propagation will be explored. Finally the mechanism of ignition and premixed flame propagation of LNG multicomponent fuel can be revealed. This project is expected to provide the required experimental data and the theoretical support for the optimization design of the ignition systems of marine LNG engines and for the LNG combustion in a safe, efficient and clean manner.

英文关键词： Marine LNG fuel;Ignition energy;Flame kernel formation;Flame propagation;Chemical kinetic