【摘要】 自由活塞内燃发电机(FPEG)被视为未来可以取代传统内燃机的新一代能量转换装置。本文研究了自由活塞内燃发电机的关键运行参数如过量空气系数及点火位置对FPEG系统性能的影响规律并对相关参数进行敏感性分析。仿真结果显示系统运行压缩比对过量空气系数及点火位置的变化十分敏感，当过量空气系数从0.85增加到1.15时，系统运行压缩比从15.8下降到6.6，而当点火位置从15 mm增加到20 mm时，系统运行压缩比从6.1增加到13.3。系统运行频率对过量空气系数的变化更为敏感，但系统指示热效率和摩擦损失则对点火位置的变化更加敏感，传热损失对过量空气系数和点火位置的变化敏感度接近。为了维持系统稳定高效运行，过量空气系数应维持在略低于1.0的状态，并且在选择点火位置时，需要考虑缸内压力升高所带来的重要部件结构损坏的风险。更多还原

【Abstract】 The free-piston engine generator(FPEG) is regarded as the next generation of energy conversion system which may replace traditional engines in the future. The effect of key operational parameters like excess air ratio of input mixture and ignition position on the engine performance of a dual-cylinder FPEG was investigated, and their sensitivity was analyzed in this paper. The operating compression ratio of the system is susceptible to changes in excess air ratio and ignition position. At the same time, it decreases from 15.8 to 6.6 when excess air ratio increases from 0.85 to 1.15, but it increases from 6.1 to 13.3 as ignition position increases from 15 mm to 20 mm. The operating frequency and indicated power are more sensitive to changes in excess air ratio than ignition position. But it is the opposite for the indicated thermal efficiency and friction loss. Excess air ratio and ignition position have a quite similar influence on heat transfer.Therefore, from the perspective of system operation and performance, it is preferable to keep excess air coefficient slightly below 1.0. In contrast, when selecting ignition position, it is of great importance to comprehensively consider the risk of structural damage caused by the increase in the compression ratio and in-cylinder gas pressure.更多还原