Investigation of performance of free-piston engine generator with variable-scavenging-timing technology under unsteady operation condition
Investigation of performance of free-piston engine generator with variable-scavenging-timing technology under unsteady operation condition
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DOI：
10.1016/j.applthermaleng.2021.117288
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发表时间：
2021-09
影响因子：
6.4
通讯作者：
Chen Ziwen;Boru Jia;Zhenfang Xin;H. Feng;Zhengxing Zuo;A. Smallbone;A. Roskilly
中科院分区：
文献类型：
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作者：
Chen Ziwen;Boru Jia;Zhenfang Xin;H. Feng;Zhengxing Zuo;A. Smallbone;A. Roskilly
大量的自由活塞发动机发电机仍然使用交叉扫气，这限制了扫气质量和非定常条件下的性能。变扫气定时技术是一种改变固定扫气过程使扫气过程与活塞运动协调的新方法。本文研究了可变扫气正时技术对自由活塞发动机发电机的影响。在自由活塞发动机发电机具有不同压缩比、循环变动和频率的设计情况下，可变扫气正时技术改善了扫气品质和性能。采用可变扫气正时技术的自由活塞发动机发电机在不同压缩比下的输出比平均降低约0.3，在不同循环变动下的输出比平均降低约0.18，在不同频率下的输出比平均降低约0.2。FPEG的捕集效率提高到70%以上，清除率保持在85%以上。对于不同的压缩比，功率平均增加0.18千瓦。而在其他工况下，功率平均提高了0.2kW。指示效率的提高幅度在1%~ 2%之间。讨论了不同非定常工况下自由活塞发动机发电机性能的变化。
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 scavenging process so that the scavenging process is coordinated with piston movement. This paper investigated effects of the variable-scavenging-timing technology implemented on the free-piston engine generator. In designed case that the free-piston engine generator has different compression ratios, cyclic variation and frequency, the variable-scavenging-timing technology improved the scavenging quality and performance. The delivery ratio of the free-piston engine generators applied with the variable-scavenging-timing technology decreased about 0.3 at different compression ratios, 0.18 at different cyclic variations and 0.2 at different frequencies on average. The trapping efficiency of FPEG rose over 70% and the scavenging efficiency was maintained at least 85%. As for different compression ratios, the power increased by an average of 0.18 kW. While the power was improved 0.2 kW on average under the other condition. The increase of indicated efficiency had an increase varying from 1% to 2% compared with before. The changes of the performance about free-piston engine generators under different unsteady condition also were discussed.