摘要
研究不同喷油策略对自由活塞发动机燃烧排放性能的影响,探索了适合自由活塞发动机柴油燃烧系统的喷油策略。基于AVL FIRE仿真平台,搭建三维动网格计算模型,通过台架试验数据,对试验喷油策略为矩形的缸压数据进行标定,验证了模型的准确性。然后对4种不同曲线形状喷油策略(普通三角形、等腰三角形、矩形和梯形)下的发动机燃烧放热及排放性能进行了仿真计算。研究结果表明:压缩上止点前采用矩形喷油策略缸内油气混合速率最快,压缩上止点后采用等腰三角形喷油策略更有利于油气混合;等腰三角形喷油策略下发动机峰值燃烧压力最大,最接近上止点,而且指示热效率最大,达到0.371;等腰三角形喷油策略下,缸内峰值燃烧压力和温度最大,NO排放最高而碳烟排放最低。
The effect of different fuel injection strategies on the combustion and emissions of a free-piston linear engine was researched,and diesel fuel injection patterns suitable for the engine were explored.A three dimensional moving mesh model was established based on the AVL FIRE platform,and the accuracy of the simulation model was validated by the experimental in-cylinder pressure under a rectangle-shaped injection strategy.The engine combustion and emissions under four different injection strategies(normal triangle-shaped,isosceles triangle-shaped,rectangle-shaped and trapezoid-shaped)were simulated.The results indicated that the mixing rate in cylinder was the greatest when adopting the rectangle-shaped injection strategy before the top dead center(TDC),and the mixture homogeneity was better when employing the isosceles triangle-shaped injection strategy after TDC.The peak pressure in cylinder was the greatest and nearest to TDC when adopting the isosceles triangle-shaped injection strategy,with which the indicated thermal efficiency was the highest,reaching 0.371.Besides,the NO mass fraction under the isosceles triangle-shaped injection strategy was the largest while the soot emission was the least among the four injection strategies.
作者
张鹏博
何义团
袁晨恒
邵毅明
ZHANG Pengbo;HE Yituan;YUAN Chenheng;SHAO Yiming(School of Traffic&Transportation,Chongqing Jiaotong University,Chongqing 400074,China)
出处
《内燃机工程》
EI
CAS
CSCD
北大核心
2019年第6期43-49,共7页
Chinese Internal Combustion Engine Engineering
基金
国家自然科学基金项目(51805056)
重庆市研究生教育创新基金项目(2018S0134)~~
关键词
自由活塞发动机
喷油策略
燃烧
排放
热效率
free piston engine
injection strategy
combustion
emissions
thermal efficiency
