自由活塞发动机活塞环密封特性研究  

Sealing Characteristics of Piston Ring in a Free-Piston Diesel Engine for Linear Alternator

作　　者：袁晨恒[1] 冯慧华[1] 王梦秋[1] 左正兴[1] 

机构地区：[1]北京理工大学机械与车辆学院,北京100081

出　　处：《内燃机工程》2015年第5期151-156,共6页Chinese Internal Combustion Engine Engineering

基　　金：国家自然科学基金资助项目(51006010);高等学校学科创新引智计划资助项目(B12022)

摘　　要：为获得自由活塞发动机活塞环密封特性,基于热力学方程和一维等熵流动方程建立了工作过程活塞环密封数学模型,对比发动机静态密封试验数据对模型进行了修正。运用所建密封模型和已有工作过程计算模型分析了自由活塞发动机和传统发动机活塞环密封特性之间的差异,并研究了相关参数对自由活塞发动机漏气损失的影响规律。研究发现:一个循环时间内,自由活塞发动机活塞环密封工作的时间较传统发动机长,但缸内气体泄漏质量较少;压缩过程中,自由活塞发动机缸内气体泄漏质量较多,但燃烧过程和膨胀过程泄漏的质量较少;选取适当的压缩比、活塞环间距和电磁负载有助于减小漏气损失。In order to study the sealing characteristics of piston ring in free-piston engine, a mathematic model of piston ring sealing in cylinder was established based on thermodynamics equations and one dimensional isentropic flow equation. The effectiveness of the sealing model was verified with the experimental data of static sealing in engine. The difference of piston rings sealing in crankshaft-piston engine and free-piston engine with the same cylinder diameters was obtained and analyzed with the mathematic sealing model and an existing engine performance model. The results show that the piston ring of free-piston engine possesses a longer sealing time than the piston ring of crankshaft-piston engine with less gas leak in one working circle. In compression stroke, gas leak in the combustion chamber of free-piston engine are more than that in crankshaft-piston engine, but less in combustion and expansion strokes. Selection of appropriate compression ratio, rings spacing and electromagnetic load is helpful for reducing leakage loss.

关 键 词：内燃机 自由活塞发动机 活塞环 密封 漏气损失 

分 类 号：TK441[动力工程及工程热物理—动力机械及工程]