(1. 中国汽车工程研究院股份有限公司,重庆,401122;
2. 湖南大学 先进动力总成技术研究中心,湖南 长沙,410082;
3. 汽车噪声振动和安全技术国家重点实验室,重庆,401122)
摘 要: 为了揭示多缸发动机各缸燃烧过程的差异及其影响因素,针对一款先进车用直列4缸增压直喷汽油机,基于AVL试验台架分别开展外特性和部分负荷工况下的试验研究。通过对比分析各缸燃烧过程参数及关联参数,得出各缸燃烧不均匀性的变化规律及影响因素。研究结果表明:在外特性下,随着转速增加,各缸平均指示压力(pIME)的不均匀性增加,泵气平均有效压力(pPME)的不均匀性变化不明显,各缸pIME相对偏差基本在6%以内;在部分负荷下,各缸pIME、最高爆发压力、pPME、最大缸压升高率的不均匀性随着负荷增加逐渐上升,但各缸燃烧循环变动率、50%燃烧点位置的不均匀性随着负荷增加基本不变,各缸10%~90%燃烧持续期的不均匀性随负荷增加而下降;pPME在一定程度上缓解了各缸pIME的不均匀性。
关键词: 直喷汽油机;进气增压;燃烧不均匀性;循环变动
(1. State Key Laboratory of Vehicle NVH and Safety Technology, Chongqing 401122, China;
2. Research Center for Advanced Powertrain Technology, Hunan University, Changsha 410082, China;
3. China Automotive Engineering Research Institute Co. Ltd., Chongqing 401122, China)
Abstract:To reveal the differences and influencing factors in the combustion process of each cylinder of the multi-cylinder engine, the experimental studies for an advanced automotive inline 4-cylinder supercharged direct injection gasoline engine under external characteristics and part load conditions were carried out based on the intake and exhaust parameters and combustion data of each cylinder measured by the AVL test bench. By comparing and analyzing the combustion process parameters and related parameters of each cylinder, the variation law and influencing factors of the combustion unevenness of each cylinder were obtained. The results show that, Influnced by the external characteristics, when the speed increases, the unevenness of each cylinder of the indicated mean effective pressure(pIME) increases, the unevenness of each cylinder of the pumping mean effective pressure (pPME) does not change significantly, and the relative deviation of the pIME of each cylinder is basically within 6%. Under partial load, the unevenness of each cylinder of the pIME, the highest burst pressure, pPME and the increase rate of the maximum pressure gradually increase with the increase of load, but the unevenness of each cylinder of the change rate of combustion cycle and the position of 50% combustion point are basically unchanged with the increase of load, and the unevenness of each cylinder of the 10%-90% burning duration decreases with the increase of load. pPME alleviates the unevenness of each cylinder of the pIME to some extent.
Key words: direct injection gasoline engine; intake supercharging; combustion unevenness; cycle change