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目的:化学反应机理在内燃机计算流体动力学(CFD)仿真中起关键作用。基于敏感性分析与粒子群寻优算法,本文旨在提出适用于内燃机CFD仿真的焦炉气化学反应机理,为焦炉气在内燃机上的应用研究提供条件。创新点:1.结合敏感性分析与离子群寻优算法,对化学反应机理参数进行了优化;2.建立了焦炉气化学反应机理,可准确仿真滞燃期、层流火焰速度、缸内压力变化和NOx生成。方法:1.根据简单碳氢燃料机理结构,搭建焦炉气化学反应机理(图1);2.通过敏感性分析,获得在燃烧中起关键作用的化学反应(图2和3);3.通过粒子群寻优算法,对上述关键化学反应的动力学参数进行优化(图4和5);4.通过数值仿真,验证机理的准确性(图6~13、16和17)。结论:1.根据敏感性定义,搭建的敏感性分析模型可准确地识别在燃烧过程中起关键作用的化学反应;2.基于粒子群寻优算法搭建的优化模型可对化学反应的动力学参数进行合理优化;3.优化后得到的焦炉气化学反应机理可准确预测滞燃期与层流火焰速度以及模拟内燃机缸内压力变化与NO_x生成。
Aim: The chemical reaction mechanism plays a key role in computational fluid dynamics (CFD) simulations of internal combustion engines. Based on the sensitivity analysis and particle swarm optimization algorithm, this paper aims to put forward the chemical reaction mechanism of coke oven gas suitable for CFD simulation of internal combustion engine, and provide the conditions for the research of coke oven gas on internal combustion engine. Innovative points: 1. Combining sensitivity analysis and ion group optimization algorithm, the parameters of chemical reaction mechanism are optimized.2. The gas chemical reaction mechanism of coke oven gas is established, which can simulate the flame retardancy, laminar flow flame velocity, Pressure changes and NOx generation. Methods: 1. Based on the simple hydrocarbon fuel mechanism structure, a coke oven gas chemical reaction mechanism is set up (Figure 1); 2. The chemical reactions that play a key role in combustion are obtained by sensitivity analysis (Figure 2 and 3); The particle swarm optimization algorithm is used to optimize the kinetic parameters of the above mentioned key chemical reactions (Figures 4 and 5). 4. The numerical simulation verifies the accuracy of the mechanism (Figures 6-13, 16 and 17). According to the definition of sensitivity, the sensitivity analysis model can accurately identify the chemical reactions that play a key role in the combustion process.2. The optimization model based on particle swarm optimization algorithm can determine the kinetic parameters of chemical reaction 3.The chemical reaction mechanism of coke oven gas obtained after optimization can accurately predict the flame retardancy and the laminar flow flame velocity as well as simulate the cylinder pressure variation and NO_x generation in the internal combustion engine.