单组元液压自由活塞发动机关键技术

为解决传统内燃式液压自由活塞发动机对压缩比控制要求严格的缺点,采用单组元推进剂代替传统的矿物燃料,利用单组元燃料催化分解后释放出的高温混合气推动活塞组件往复运动,提出了一种对外输出液压能的新型液压自由活塞发动机.采用Fluent软件模拟在脉冲工作方式下,催化床的床载、比表面积、孔隙率、流阻等对单组元燃料分解特性和寿命的影响.通过在动力腔头部安装辅助电磁排气阀的方式来提高活塞的运行频率,提高输出功率.采用隔热陶瓷和合理的排气口设计来减小动力腔壁面热量损失,提高输出功率.利用软密封和硬密封相结合的方式来阻止动力腔的气体进入液压泵,保证了系统工作可靠.

Key technologies on monopropellant-powered hydraulic free piston engine

A new type of hydraulic free piston engine was proposed to overcome the shortcomings of the traditional internal combustion hydraulic free piston engine which needs to  control the compression ratio exactly. The new type  engine uses the decomposed hot gases released by the monopropellant to drive the piston assembly to and fro and output  hydraulic energy. The influences of the bed load, area ratio, porous and resistance of the catalyst bed on the monopropellant decomposition were studied, and the life of the  catalyst bed under the pulse working style was analyzed using Fluent. The operation frequency of the piston and the power output were improved by inserting an exhaust solenoid  valves to the dynamic cylinder. The adiabatic ceramic and the suitable design of exhaust ports  can reduce the heat loss through the dynamic cylinders. Both the soft seal and  hard seal were introduced to reduce the gas in the dynamic cylinder flow into the hydraulic pump and made the system work reliably．