单活塞式液压自由活塞柴油机工作特性的试验研究

An Experimental Study on the Working Characteristics of a Single Piston Hydraulic Free-piston Diesel Engine

对所研制的单活塞式液压自由活塞柴油机原理样机的工作特性进行研究。结果表明,活塞动力学与传统内燃机存在较大差异,通过改变停止在下止点的时间可控制活塞运动频率,实现功率调节。燃烧的主要阶段为速燃期,大部分燃油在速燃期内燃烧,放热速度较快。泵腔进出油阀的响应性影响泵腔压力的建立过程,提高进出油阀的响应性可改善燃烧过程,增加液压功率输出和提高液压自由活塞柴油机的工作效率。

The working characteristics of the principle prototype of a single piston hydraulic free-piston diesel engine （HFPDE） are studied. The results indicate that the piston dynamics of HFPDE differs from those of conventional engines, and the frequency of piston movement can be controlled and hence the power can be adjusted by changing the dwelling time of piston at the bottom dead center. The main combustion phase in HPFDE is rapid combustion phase, in which most of the fuel bums, resulting in higher rate of heat release. The responsibility of suction and discharge valves in pump chamber has certain effects on the building up process of pump chamber pressure. Raising their responsibility can improve combustion, increase hydraulic power output and enhance the efficiency of HFPDE.