路试状态汽油机缸内热功转换过程性能及影响因素的-中南大学学报.PDF

第 48 卷第 5 期 中南大学学报( 自然科学版) Vol.48 No.5 2017 年 5 月 Journal of Central South University (Science and Technology) May 2017 DOI: 10.11817/j.issn.1672-7207.2017.05.034 路试状态汽油机缸内热功转换过程性能及 影响因素的检测与分析 唐琦军，刘敬平，付建勤，易鹏，朱国辉 (湖南大学 先进动力总成技术研究中心，湖南 长沙，410082) 摘要：提出一种能对整车实际路试工况下汽油机的多项运行及性能参数进行连续检测与诊断的方法，应用于某车 辆的实际路试工况，获得汽油机瞬态参数，并对该样机进行系统的稳态台架试验。研究结果表明：无论是台架稳 定工况还是实车瞬变工况，汽油机缸内热功转换效率主要与 50%放热量的位置以及过量空气系数相关；当 50%放 热量的位置出现在上止点后 10°左右(高速略早、低速略晚)时，高压循环热效率达到峰值；而影响 50%放热量的 位置有点火提前角、转速、负荷、缸内残余废气系数和过量空气系数等参数；该样机标定时由于对缸内残余废气 系数的变化缺乏了解，瞬变工况下的过量空气系数与理想值有偏差，从而影响实际热效率；某些过渡工况下点火 提前角变化异常，导致热效率偏离理想值。 关键词：汽油机；瞬变工况；燃烧放热规律；热功转换效率 中图分类号：TK417+.4 文献标志码：A 文章编号：1672−7207(2017)05−1384−07 Diagnostics and analysis of heat to work conversion process and major influencing parameters of IC engine under road test conditions TANG Qijun, LIU Jingping, FU Jianqin, YI Peng, ZHU Guohui (Research Center for Advanced Powertrain Technology, Hunan University, Changsha 410082, China) Abstract: A new approach was demonstrated which enables continuous detection and judgment of multi controlling and performance parameters in an automotive IC engine under actual road testing conditions. The transient performance parameters of engine were obtained from the typical road testing operations. Steady state engine tests were conducted to help understanding what were observed during the transient tests. The results show that 50% burning position and the relative air-fuel ratio (AFR) are the two most important key factors for the heat to wor