Study on adaptive behavior and mechanism of compression ratio (or piston motion profile) for combustion parameters in hydraulic free piston engine
Study on adaptive behavior and mechanism of compression ratio (or piston motion profile) for combustion parameters in hydraulic free piston engine
复制标题
液压自由活塞发动机压缩比（或活塞运动曲线）对燃烧参数的自适应行为及机理研究
DOI：
10.1016/j.apenergy.2017.11.100
复制
发表时间：
2017
期刊：
影响因子：
11.2
通讯作者：
Zhiyong Li
中科院分区：
文献类型：
--
作者：
Heming Geng;Yang Wang;Xudong Zhen;Yu Liu;Zhiyong Li
液压自由活塞发动机（HFPE）的活塞运动曲线是由缸内气体和液压流体的复合力控制的。通过对HFPE活塞运动的动力学计算分析，发现活塞运动曲线和压缩比对燃烧参数的变化具有自适应性。随着燃烧正时提前，活塞换向时间提前，并且CR减小。通过样机试验验证了这种自适应特性的存在，并证明了HFPE对混合气浓度变化具有自适应特性。该自适应特性可使HFPE有效避免爆震或二次燃烧现象，使其最大缸内气压和最大放热率值稳定，减少指示功损失，使输出功率保持相对稳定。
The Hydraulic Free Piston Engine (HFPE) piston motion profile is controlled by the composite force of the in-cylinder gas and hydraulic fluid. Based on the analysis of HFPE piston motion by dynamic calculations, it is found that the piston motion profile and compression ratio (CR) are self-adaptive for the variation of combustion parameters. As the combustion timing is advanced, the piston commutation time is advanced, and the CR is decreased. Further, the existence of this self-adaptive features are demonstrated by a prototype test of HFPE, and it also proves that HFPE has self-adaptive features for the variation of mixture concentration. The self-adaptive features can make HFPE effectively avoid the phenomenon of knocking or post-combustion, make it stable of the maximum in-cylinder gas pressure and maximum value of heat release rate, reduce the loss of indicated work, and keep the output power relatively stable.