A dual assisted compression ignition combustion mode is researched on a hydraulic free piston engine. The dual assisted compression ignition combustion mode is realized by combining a glow plug with a spark plug in the ignition system to assist the homogeneous charge compression ignition combustion. The effects of control parameters and operating parameters on dual assisted compression ignition combustion mode are revealed by experiments. It is found that as the compression ratio increases, the combustion characteristics of dual assisted compression ignition change from spark ignition to two-stage heat release. The dual assisted compression ignition combustion has more controllability on the combustion phase and the heat release rate than glow plug assisted compression ignition due to the direct and stable spark ignition. When the temperature of the glow plug is lower, the heat release phase is dominated by the spark plug. With the temperature further increases, the heat release process is mainly controlled by the glow plug. The dual assisted compression ignition combustion has a wider compression ratio range than spark assisted compression ignition to guarantee the high indicated thermal efficiency. The suitable methanol/air equivalence ratio range for dual assisted compression ignition combustion mode is between 0.6 and 0.8.

在无液压活塞发动机上研究了双辅助压缩点火燃烧模式。通过在点火系统中组合电热塞和火花塞来实现双重辅助压缩点火燃烧模式，以协助均质充量压缩点火燃烧。实验揭示了控制参数和运行参数对双辅助压缩点火燃烧模式的影响。发现随着压缩比的增加，双辅助压缩点火的燃烧特性从火花点火变为两级放热。由于直接和稳定的火花点火，与电热塞辅助的压缩点火相比，双辅助压缩点火燃烧在燃烧阶段和放热率上具有更大的可控性。当电热塞的温度较低时，放热阶段由火花塞控制。随着温度的进一步升高，放热过程主要由电热塞控制。双辅助压缩点火燃烧比火花辅助压缩点火具有更大的压缩比范围，以确保较高的指示热效率。双辅助压缩点火燃烧模式的合适的甲醇/空气当量比范围在0.6到0.8之间。双辅助压缩点火燃烧比火花辅助压缩点火具有更大的压缩比范围，以确保较高的指示热效率。双辅助压缩点火燃烧模式的合适的甲醇/空气当量比范围在0.6到0.8之间。双辅助压缩点火燃烧比火花辅助压缩点火具有更大的压缩比范围，以确保较高的指示热效率。双辅助压缩点火燃烧模式的合适的甲醇/空气当量比范围在0.6到0.8之间。