典型燃油多步化学反应机理研究

发布时间：2018-05-14 14:26

本文选题：正癸烷 + 简化机理　；参考：《南京航空航天大学》2015年硕士论文

【摘要】：为了准确预测RP-3型航空煤油的点火和燃烧特性,为在役或下一代航空发动机主燃烧室、加力燃烧室或超燃冲压发动机燃烧室的两相喷雾燃烧过程数值预估提供可靠的化学反应机理计算模块,本文对RP-3型航空煤油替代燃料及其多步化学反应机理进行基础研究。本文具体研究内容包括以下三个方面:1)确定正癸烷作为RP-3型煤油的替代燃料及其详细化学反应机理(62组分344步),并在预混燃烧器中对正癸烷的燃烧特性进行分析,和试验数据进行对比分析,结果表明其可以作为RP-3型航空煤油的替代燃料。随后基于敏感性分析和反应流分析方法,对正癸烷详细化学反应机理进行简化,建立一种36组分62步简化反应机理,并在完全搅拌反应器和预混燃烧器中进行计算,与详细机理结果和试验数据进行对比。结果表明:完全搅拌反应器中62步简化机理计算得到的平衡温度、反应物和主要生成物的摩尔分数与344步详细化学反应机理计算结果整体变化趋势吻合较好;预混燃烧器中62步简化机理得到的进口反应物和出口生成物摩尔分数与详细机理结果和试验数据稍有差异,但变化趋势基本一致;62步简化机理能在较大范围内反映正癸烷的燃烧性能。2)独立设计了本生灯预混预蒸发燃烧试验台,对RP-3型煤油预混预蒸发燃烧火焰进行了试验测量,结果表明:本生灯预混预混蒸发火焰稳定燃烧的油气比大于0.0603;当灯管内流体雷诺数大于1150时,层流火焰过度到湍流火焰;火焰焰心、内焰、外焰高度可以均可通过CH4、UCH、CO2、温度等的极值点位置来判断;不同工况下的火焰中心轴线和不同高度截面径向上温度和烟气组分浓度总体变化趋势基本是相同的。3)以试验用的本生灯预混预蒸发燃烧火焰为数值模拟对象,建立数值模拟网格,采用三种航空煤油替代燃料及其多步简化化学反应机理对本生灯预混预蒸发燃烧火焰进行数值模拟,并和相应的试验数据相比较。计算结果表明:标准k-e湍流模型和EDC燃烧模型能较好的描述本生灯燃烧火焰,可用于后续本生灯预混预蒸发燃烧火焰的研究;三种简化机理中心截面上流场,以及中心截面和不同高度截面的温度、O2浓度和CO2浓度分布基本相同;在各工况下,62步简化机理计算的火焰中心轴线和不同高度截面径向上的温度、O2浓度、CO2浓度和试验数据能很好的吻合,能对火焰温度和烟气组分进行较准确和可靠的预测;23步简化机理在各工况下的计算结果和试验数据都相差很远,因此C12H23的23步简化机理不能准确的预测RP-3型煤油的预混预蒸发燃烧过程;38步简化机理在贫油时能对轴线温度,在富油时对轴线O2做出一定预测,但不能对CO2进行准确的预测。本文所提出的正癸烷62步简化机理能较准确描述我国RP-3型煤油的实际燃烧过程,为发动ii机燃烧室的数值模拟提供可靠的化学反应机理计算模块。
[Abstract]:In order to accurately predict the ignition and combustion characteristics of RP-3 type aviation kerosene, a reliable chemical reaction mechanism calculation module is provided for the numerical prediction of the two phase spray combustion process for the main combustion chamber of the active or next generation aero engine, the afterburner or the combustor of the scramjet combustor. In this paper, the RP-3 type aviation kerosene substitute fuel and its multistep process are used in this paper. The basic research of the mechanism of the reaction is carried out in this paper. The following three aspects are as follows: 1) determining the substitution of the RP-3 type kerosene as a substitute fuel and the detailed chemical reaction mechanism (62 components 344 steps), and the analysis of the combustion characteristics of the positive in combustor in the premixed burner, and the comparison and analysis of the experimental data. The results show that it can be used. As an alternative fuel for RP-3 type aviation kerosene, based on the sensitivity analysis and reaction flow analysis, the mechanism of the detailed chemical reaction of the positive subunit was simplified, and a 36 component 62 step simplified reaction mechanism was established and calculated in a complete stirred reactor and a premixed burner, and compared with the detailed mechanism results and the experimental data. The results show that the equilibrium temperature is calculated by the 62 step simplified mechanism in the complete stirred reactor. The mole fraction of the reactant and the main product is in good agreement with the overall change trend of the 344 step detailed chemical reaction mechanism. The molar fraction of the inlet reactant and the export product obtained by the 62 step simplification mechanism in the premixed burner and the details are detailed. The mechanism results are slightly different from the experimental data, but the change trend is basically the same. The 62 step simplification mechanism can reflect the combustion performance of the.2 in a larger range. The premixed premixed pre evaporative combustion test bench is designed independently and the premixed premixed combustion flame of RP-3 type kerosene is tested. The results show that the premixed premixed evaporation of the Benson lamp is made. The fuel gas ratio of the flame stable combustion is greater than 0.0603, and when the Reynolds number in the tube is more than 1150, the laminar flame is over to the turbulent flame, and the flame core, the inner flame and the outer flame can be judged by the extreme point position of CH4, UCH, CO2, temperature and so on; the center axis of the flame and the radial temperature and smoke at different height sections under different working conditions The overall variation trend of component concentration is basically the same.3). The numerical simulation grid is set up with the premixed pre evaporating combustion flame of the experimental Benson lamp as the numerical simulation object. The numerical simulation of the premixed premixed combustion flame of the Benson lamp is simulated with three kinds of aviation kerosene substitute fuel and its multi step simplified chemical reaction mechanism. The results show that the standard k-e turbulence model and the EDC combustion model can describe the burning flame of the Benson lamp well. It can be used for the subsequent study of pre mixed premixed combustion flame of the Benson lamp; the flow field on the central section of the three simplified mechanisms, the temperature of the central section and the different height section, the distribution of O2 concentration and the concentration of CO2 are basic. In the same condition, the 62 step simplified mechanism calculated the central axis of the flame and the temperature on the radial section of the different height, the concentration of O2, the concentration of CO2 and the experimental data can be in good agreement, and can make a more accurate and reliable prediction of the flame temperature and the smoke composition, and the difference between the calculation results and the experimental data of the 23 step simplification mechanism at various working conditions. So the 23 step simplification mechanism of C12H23 can not accurately predict the premixed premixed combustion process of RP-3 type kerosene; the 38 step simplification mechanism can make a certain prediction on the axis temperature and the axis O2 in the oil rich, but can not accurately predict the CO2. The 62 step simplification mechanism proposed in this paper can describe our country accurately. The actual combustion process of RP-3 kerosene provides reliable chemical reaction mechanism calculation module for the numerical simulation of II combustion chamber.

【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：V231.2;V312

【参考文献】