Identification and analysis on the variation sources of a dual-cylinder free piston engine generator and their influence on system operating characteristics
Identification and analysis on the variation sources of a dual-cylinder free piston engine generator and their influence on system operating characteristics
复制标题
DOI：
10.1016/j.energy.2021.123001
复制
发表时间：
2021-12
期刊：
影响因子：
9
通讯作者：
Zhi-Li Zhang;H. Feng;Boru Jia;Zhengxing Zuo;X. Yan;A. Smallbone;A. Roskilly
中科院分区：
文献类型：
--
作者：
Zhi-Li Zhang;H. Feng;Boru Jia;Zhengxing Zuo;X. Yan;A. Smallbone;A. Roskilly
稳定燃烧是双缸自由活塞发动机发电机（FPEG）面临的巨大挑战。燃烧变化容易发生，因为活塞运动只受作用在运动部件上的力的影响，没有机械结构的限制。本文研究了双缸fpeg循环和缸间变化的来源，并利用已建立的工作模型进一步分析了它们对活塞运动特性和发动机性能的影响。研究表明，FPEG具有一定的抗干扰性能，但易受外界条件和操作参数的影响。FPEG系统的运行应该限制在一个特定的范围内，而不是像传统内燃机那样固定在一个固定的压缩比上。仿真结果表明，无论是单缸还是双缸，在没有失火的情况下，FPEG系统只需几个循环就能恢复到一次燃烧变化的稳定运行状态。当一个圆柱体发生连续变化时，操作中心偏离几何中心。当燃烧发生变化时，压缩比和工作频率降低，但在正常气缸中压缩比明显降低。当两个气缸连续变化时，压缩比、工作频率和自由活塞发动机性能都会显著降低。
Stable combustion is a huge challenge for dual-cylinder free-piston engine generator (FPEG). Combustion variations are easy to occur, because the piston movement is only affected by the forces acting on the moving parts, and there is no mechanical structure limit. This paper has investigated the sources of cyclic and cylinder-to-cylinder variations for dual-cylinder FPEGs, and further analysed their effect on the piston movement characteristics in operation and engine's performance by using an established working model. This study reveals that FPEG has specific anti-interference properties but is easily affected by external conditions and operating parameters. The operation of the FPEG system should be limited to a specific range rather than fixed at a fixed compression ratio like a traditional internal combustion engine. The simulation results showed that the FPEG system returns to a stable operating state within just a few cycles for one-time combustion variations if there are no misfires, regardless of whether they occur in one cylinder or two cylinders. The operating centre deviates from the geometric centre when continuous variations occur in just one cylinder. The compression ratios and operating frequency decrease when combustion variations occur, but the compression ratio decreases significantly in normal cylinders. When continuous variations occur in two cylinders, the compression ratio, operating frequency, and free-piston engine performance are significantly reduced.