基于分形理论的柴油引燃天然气发动机燃烧模型

以柴油引燃天然气发动机为研究对象,针对柴油引燃油的扩散燃烧和天然气气体燃料的均质预混燃烧的特点,分别建立了引燃油多区燃烧模型和基于分形理论的预混天然气气体燃料燃烧模型.在试验验证所建模型的基础上,分析了引燃油量、喷油提前角和发动机转速对柴油引燃天然气发动机性能的影响.研究表明,适当增加引燃油量和减小喷油提前角可以降低柴油引燃天然气发动机的最大缸内压力升高率,从而有利于遏制柴油引燃天然气发动机高负荷时的爆震倾向.

Combustion Model of Natural Gas Engine Ignited by Pilot Diesel Based on Fractal

A combustion model of natural gas engine ignited by pilot diesel was developed, which includes a multi-zone combustion sub-model for the diffusion combustion of the pilot fuel, and a gas combustion sub-model based on fractal for the homogenous combustion of the natural gas. On the basis of experiment, studies in variation of engine parameters with quantity of pilot, injection timing and rotate speed of the engine were carried out. it is revealed that increasing the amount of pilot fuel and retarding the fuel injection timing suitably will reduce the maximum pressure rise rate effectively, and this is beneficial to keep an engine away from knock at high load.