点燃式发动机燃用不同燃料的燃烧特性及循环变动  

Combustion Characteristics and Cycle-by-Cycle Variations of Spark-Ignition Engine Fueled with Different Fuels

作　　者：刘帅[1] 王忠[1] 赵洋[1] 瞿磊[1] 孙波[1] Liu Shuai Wang Zhong Zhao Yang Qu Lei Sun Bo(School of Automobile and Traffic Engineering, Jiangsu University, Zhenjiang 212013, China)

机构地区：[1]江苏大学汽车与交通工程学院,镇江212013

出　　处：《燃烧科学与技术》2016年第4期349-356,共8页Journal of Combustion Science and Technology

基　　金：国家自然科学基金资助项目(51376083);江苏省高校自然科学基金重点资助项目(13KJA470001);2011年江苏高校优势学科建设工程资助项目(苏政发办[2011]6号);江苏省2013年度普通高校研究生科研创新计划项目(CXZZ13_0672);江苏省2014年度普通高校研究生科研创新计划项目(KYLX_1035)

摘　　要：围绕点燃式发动机燃用汽油、LPG和CNG的燃烧特性及循环变动开展了研究.发动机在最大转矩工况运行,分别从压力参数方面及燃烧参数方面对循环变动进行了分析.结果表明,汽油的燃烧循环变动系数最小,LPG燃烧过程中循环变动系数增大,CNG燃烧过程中循环变动系数最大;燃烧阶段循环变动是产生发动机循环变动的主要原因,采用进气道预混的方式燃用气体燃料时,进气阶段变动是造成发动机循环变动的原因之一;汽油燃烧时,火焰发展期与燃烧持续期线性相关,良好的着火决定燃烧过程的稳定,LPG和CNG燃烧时,火焰发展期与燃烧持续期的相关性减弱,着火和火焰的传播共同影响燃烧过程的稳定性;放热率型心与平均指示压力有良好的线性关系,说明发动机的平均指示压力受放热过程的影响.This investigation took cyclic variations as the research objective,and analyzed the elements which caused the cyclic variations of gasoline,LPG and CNG engines,respectively.The combustion pressures were col-lected at the maximum torque to analyze the relationship between combustion pressure and the crank angle of peak pressure.Furthermore,standard deviation and variation coefficient analyses were applied in order to reveal the laws of flame development period and combustion duration period,heat release centroid variation and indicated mean pressure correlation.The results are stated as follows：variation coefficient increased during certain combustion cy-cles in LPG engine and variation coefficient decreased due to misfiring cycles,while thecyclic variation of gasoline engine was the smallest;the crank angle of peak pressure was barely influenced by mean indicated pressure;cyclic variations were most affected by combustion process,and intake process was a significant factor that affectscyclic variations when gas fuel was exploited with inlet premix method;for some reason,flame development period af-fected combustion duration period more in gasoline than in LPG and CNG engines,in consequence,combustion proceeded owing to excellent ignition in gasoline engine,and excellent ignition stimulated the stability of combustion and flame spread;moreover,heat release rate centroid demonstrated a good linear relationship with indicated mean pressure,showing that heat release process affected indicated mean pressure enormously.

关 键 词：点燃式发动机 汽油 液化石油气 压缩天然气 燃烧 循环变动 

分 类 号：U464.173[机械工程—车辆工程]