摘要
为了评估二冲程电热塞点火微型内燃机的燃烧特性,构建了测试平台进行燃烧测试。与常规汽油机对比分析表明:微型内燃机放热率低、循环变动大、燃烧持续期长,比常规尺寸机型燃烧持续期长约20°CA,并且平均指示压力(p_(mi))和燃烧压力低;电热塞点火形式无固定点火时间,燃烧始点波动很大,导致微空间燃烧不稳定。基于首着火循环的瞬态分析表明:微型内燃机较高的残余废气系数是微空间燃烧特性差的主要原因;无残余废气情况下,微型内燃机燃烧放热率曲线与常规机型相当,燃烧持续期约为22°CA,比稳定燃烧时缩短近50%;缸体温度和残余废气共同影响燃烧始点和燃烧持续期,但残余废气是主要影响因素;残余废气量和缸体温度越高,对应的pmi越低,当缸体温度为150℃时,稳定燃烧状态下的pmi仅为0.17 MPa。
To evaluate the combustion characteristics of a two-stroke glow-plug ignition miniature Internal Combustion Engine （ICE） , a test platform was constructed and combustion diagnoses were implemented. Analogy analysis with conventional Gasoline Engines（GEs） shows that miniature ICE has lower Rate of Heat Release （ROHR）,higher cyclic variations and longer combustion duration, about 20 °CA longer than those of conventional GEs. Besides, miniature ICE has lower indicated mean effective pressure （ pmi） and combustion pressure. Due to the unstable ignition of glowplug, the Start of Combustion （SOC） fluctuates considerably, leading to micro combustion instability. Transient analysis based on the captured first combustion cycle shows that high residual gas fraction of miniature ICE is the primary reason for the poor combustion characteristics of micro combustion. Without residual gas （the first combustion cycle）,the ROHR curve of miniature ICE approaches those of conventional GEs and the combustion duration is approximately 22 ℃A, nearly 50% shorter thanthose of stable combustion. Both engine block temperature and the residual gas affect the SOC and combustion duration, but the residual gas is the main factor. The more amount of residual gas and the higher the engine block temperature, the lower the pmi because that both of them impair the increase of intake charge. At 150 ℃,the pmi in steady combustion state is merely 0.17 MPa.
作者
唐志刚
张力
尚会超
吕晓惠
陈曦
郑仁蔚
TANG Zhi-gang ZHANG Li SHANG Hui-chao LYU Xiao-hui CHEN Xi ZHENG Ren-wei(College of Automotive Engineering , Chongqing University , Chongqing 400044 , Chin)
出处
《吉林大学学报（工学版）》
EI
CAS
CSCD
北大核心
2017年第3期811-818,共8页
Journal of Jilin University:Engineering and Technology Edition
基金
国家自然科学基金项目(51175530)
高等学校博士学科点专项科研基金项目(20130191110001)
关键词
动力机械工程
车辆工程
微型内燃机
电热塞点火
燃烧特性
残余废气
power mechanical engineering
vehicle engineering
miniature internal combustion engine （ICE）
glow-plug ignition
combustion characteristics
residual gas
