液压自由活塞发动机活塞运动特征参数变化机理与调控

项目名称： 液压自由活塞发动机活塞运动特征参数变化机理与调控

项目编号： No.51305034

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 机械、仪表工业

项目作者： 吴维

作者单位： 北京理工大学

项目金额： 26万元

中文摘要： 液压自由活塞发动机（HFPE）以在效率、排放等方面的优势，在近十几年发展迅速。与传统二冲程曲柄连杆内燃机活塞运动相比，HFPE活塞运动无解析表达、无固定运动轨迹、无固定极限位置，造成系统循环稳定性变差、功率密度和能量转换效率低于预期，系统控制的鲁棒性不足，影响了HFPE的进一步发展。基于项目组前期理论研究与试验测试结果，本项目申请拟利用与活塞直接作用的气缸气体、液压腔油液实现"虚拟曲柄连杆"的功能，并以一个机理揭示为基础，实现方法的创新。通过开展HFPE流体压力变化规律与活塞运动特性之间的耦合关系研究，揭示活塞频率、极限位置等活塞运动特征参数变化机理，获取活塞运动循环变动的分析参数变化规律，建立活塞运动循环变动的分析参数计算方法，探究引入"液压惯性模拟"思想的HFPE液压压力区间调控机制，形成液压压力区间调控方法，为提高系统循环稳定性、改善系统控制的鲁棒性提供思路。

中文关键词： 液压自由活塞发动机；非线性运动；循环变动；压力区间调控；液压混合动力

英文摘要： The hydraulic free-piston engine (HFPE) has advantages in such as efficiency, exhaust, et al. The researches on the HFPE develop fast in the past decades. Compared with the piston motion in the conventional two-stroke crank IC engine, the piston motion in the HFPE has no analytical expression, no fixed trajectory and no fixed limit position. It leads to the decrease of the cycle-by-cycle stability. The power density and the energy conversion efficiency are also reduced. The robustness of the system control is insufficient and the HFPE application is limited. Based on the former theoretical and tested results, the project application intends to use the in-cylinder gas and the hydraulic cavity oil which interact with the piston directly to perform the "virtual crank" function. By studying the coupling relationship between the HFPE fluid pressure variations and the piston motion characteristics, the change mechanism of piston motion characteristic parameters, such as the piston frequency and limit position will be revealed. The changes of the parameter for the cycle-by-cycle variation analysis of the piston motion will be proposed. The parameter calculation method for the cycle-by-cycle variation analysis of piston motion will be established. By exploring the mechanism of the HFPE hydraulic pressure interval regula

英文关键词： hydraulic free-piston engine；nonlinear motion；cycle-by-cycle variation；pressure interval regulation；hydraulic hybrid