船用LNG-柴油双燃料燃烧反应动力学及其与发动机缸内流体动力学协同作用的基础研究

项目名称： 船用LNG-柴油双燃料燃烧反应动力学及其与发动机缸内流体动力学协同作用的基础研究

项目编号： No.51479149

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 其他

项目作者： 李格升

作者单位： 武汉理工大学

项目金额： 80万元

中文摘要： 我国正积极开发LNG燃料动力船舶，其发动机主要采用LNG缸外预混进气-柴油缸内直喷双燃料燃烧模式，化学反应和缸内流动对该模式下的燃烧过程都有显著影响，而船用LNG-柴油双燃料基础燃烧数据和燃烧化学反应动力学（简称化学动力学）机理不完善，无法实现化学动力学与流体动力学的耦合计算，制约了双燃料发动机缸内燃烧规律研究，以致难以实现燃烧优化控制。本项目通过激波管和定容燃烧弹实验获取丰富的基础燃烧数据，分析双燃料着火与传播特性；重点研究LNG和柴油组分对混合燃料化学动力学的影响规律，构建双燃料的多组分替代物模型燃料及其化学动力学机理；建立化学动力学与发动机多维CFD耦合的燃烧综合计算模型，通过数值计算和发动机台架试验，揭示化学反应和缸内流动对双燃料发动机燃烧的影响规律，探索化学反应和缸内流动协同作用的高效清洁燃烧机制。该研究可为船用LNG-柴油双燃料发动机的燃烧优化控制提供重要理论支撑。

中文关键词： 船舶柴油机；LNG燃料；化学动力学；缸内流动；协同作用

英文摘要： China has been actively developing LNG(Liquefied Natural Gas)-fueled ship today, and the dual-fuel (DF) combustion mode, i.e., premixed LNG is first charged and then ignited by pilot diesel, is employed in the main engine of the ship. With this combustion mode, both the chemical reaction and in-cylinder flow have significant effects on the combustion process. Unfortunately, since the paucity of basic combustion data and chemical kinetic mechanism of the marine DF of LNG & diesel, the computational study of combustion characteristics by coupling fluid dynamics and chemical kinetics has been limited. As a result, it is difficult to carry out the combustion optimization and controlof DF engines. To address this deficiency, the present research aims to: (1) obtain sufficient combustion data of the DF using shock tube and constant-volume combustion vessel experiments to analyze the ignition and flame propagation characteristics of the DF; (2) estimate the kinetics influence of the components of LNG and diesel on the DF combustion process to develop the multi-component fuel surrogates model and combustion reaction kinetic mechanism for the DF; (3) develop a comprehensive computational-model for the comubstion process in DF engines by coupling chemical kinetic mechanism and multi-dimensional CFD (computational fluid dynamics) model. Based on these, the effects of chemical reaction and in-cylinder flow on the combustion process of DF engines can be revealed by numerical calculation and engine test, and a high-efficiency clean combustion mode based on the interaction between chemical reaction and in-cylinder flow will be proposed. The present research is capable of providing a new approach and theoretical basis to combustion optimization and control for the marine LNG & diesel dual-fuel engines.

英文关键词： Marine diesel engine;LNG fuel;Chemical kinetics;In-cylinder flow;Interaction