四冲程自由活塞发动机仿真与实验

Simulation and Test of Four-stroke Free-piston Engine

为实现清洁高效利用燃料发电,提出并研究了四冲程自由活塞发动机。基于活塞组件的动力学方程、燃烧室内的气体状态方程以及代用燃烧放热规律,建立系统仿真模型,对系统动态特性进行仿真研究,重点讨论了压缩比和膨胀比对系统性能的影响。在仿真分析的基础上,研制了一台缸径为62 mm的原理性样机,对样机实验结果进行了分析,并利用仿真模型对样机的性能参数进行了回归分析。研究结果表明:目前样机的发电效率为34%左右,优化后四冲程自由活塞发动机的发电效率在45%左右,比传统小型汽油发电机组有明显的性能优势。

A four-stroke free-piston engine was simulated and tested to achieve energy conversion from fuel to electricity.Simulation models were created based on the kinetic equation of free-piston,the equation of gas state,and an equivalent heat release rate of combustion process.Dynamic properties of the system were analyzed by using the model.Effects of the compression ratio and the expansion ratio were discussed.Based on the results of the simulation,an experimental prototype was fabricated.Testing results of the prototype were analyzed,and performance parameters were given out in detail.The generating efficiency 34% was obtained up to now,and the efficiency 45% was available after optimization.According to the simulated and tested results,the new generating system has distinct advantages to conventional gasoline generators.