高辛烷值燃料HCCI燃烧特性的变参数研究

Study of HCCI Combustion Characteristics with High RON Fuel

构建了一种高辛烷值燃料与空气压缩自燃反应机理(89种组分,413个反应)。用在快速压缩机上获得的试验数据对它进行了验证,考察了机理的有效性。然后将其嵌入内燃机模型,在CHEMKIN平台上对这种燃料的HCCI燃烧特性进行了变参数的数值模拟,研究了进气温度、进气压力、空燃比、压缩比、转速和EGR等因素对燃烧特性的影响,同时预测了缸内反应物、生成物、自由基浓度随曲轴转角变化的历程。计算结果对燃用高辛烷值燃料HCCI发动机燃烧过程的优化提供了依据。

A comprehensive chemical kinetics mechanism (89 species,413 reactions) for hydrocarbon fuels with high RON was constructed to simulate the auto-ignition process under the Homogeneous Charge Compression Ignition (HCCI) conditions.The reaction mechanism was validated by using the experimental datas from a Rapid Compression Machine.The simulated results showed a good agreement with the measurements.The ignition delay and the burning rate could be captured accurately by the simulation.The mechanism was implemented into the numerical simulation of HCCI combustion in gasoline engines combined with CHEMKIN code.The HCCI combustion characteristics were studied under different inlet temperature,inlet pressures,A/F ratios,compression ratios,engine speeds as well as EGRs.Meanwhile,the concentration variations of reactants,the major products and the radicals versus crank angle were calculated.The research results provided guidance for the optimization of HCCI combustion process.