Investigation of performance of free-piston engine generator with variable-scavenging-timing technology under unsteady operation condition

A substantial number of free-piston engine generators still use cross scavenging, which limits scavenging quality and performance under unsteady condition. Variable-scavenging-timing technology is a novel method to change the fixed process so that coordinated with piston movement. This paper investigated effects variable-scavenging-timing implemented on generator. In designed case generator has different compression ratios, cyclic variation frequency, improved performance. The delivery ratio applied decreased about 0.3 at 0.18 variations 0.2 frequencies average. trapping efficiency FPEG rose over 70% was maintained least 85%. As for power increased by an average kW. While kW other increase indicated had varying from 1% 2% compared before. changes condition also were discussed.