船用重油多元模型燃料的构建与验证

为了复现实际船用重油燃料燃烧特性，基于化学解构法原理，提出了重油多元模型燃料。选择了正十四烷、2,6,10-三甲基十二烷、四氢化萘和正癸基苯作为基础燃料，表征实际重油的正构烷烃、异构烷烃、环烷烃和芳烃成分。模型燃料的比例依据带权欧几里得距离算法进行最优化求解。针对发展的多元模型燃料，基于流动反应器试验平台对模型燃料的中低温氧化特性进行点对点比较，多组分模型燃料成功复现了典型反应物、中间产物和生成物浓度随温度变化的趋势。基于“解耦法”的机理简化方法，发展了重油多组分模型燃料骨架机理。该机理成功预测了重油馏分的中低温氧化特性。基于该骨架机理进行敏感性分析，得到出烷烃类自由基主导的基元反应对重油碳烟生成密切相关。此外，基于定容燃烧装置数值仿真结果，证明了重油多组分模型燃料对近发动机条件下的喷雾燃烧过程具有较高的预测能力。

Development and Validation of Multi-Component Surrogate for Heavy Fuel Oil

In order to reproduce combustion properties of heavy fuel oil, multi-component surrogate has been proposed based on chemical deconstruction method. Surrogate components consisted of n-tetradecane, farnesane, tetralin and n-decylbenzene, instead of n-alkanes, iso-alkanes, cyclo-alkanes and aromatics in the target fuel, respectively. Besides, the optimal proportions of surrogates were determined by weighted Euclidean distance algorithm. In consideration of point-to-point validations of oxida-tion properties, experiments were conducted in a laminar flow reactor. Results showed that multi-component surrogate suc-cessfully reproduced concentration profiles of reactants, intermediates and products under low to intermediate temperature, which indicated the high-fidelity of multi-component surrogates. Based on decoupling methodology, skeletal mechanism for multi-component surrogates was proposed and developed. The computational results based on the mechanism agreed well with the experimental data in flow reactor. Furthermore, the mechanism of multi-component surrogate was applied in the exploration of intrinsic combustion behaviors of heavy fuel oil. According to the sensitivity analyses of ethylene, elementary reactions related to large n-alkane contribute a lot to soot formation in the combustion of heavy fuel oil. Besides, according to the results in visual constant volume combustion chamber, multi-component surrogates well predicted the spray and combustion process under engine-relevant conditions.