Cycle variations characteristic of high pressure common rail diesel engine at idle condition(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2016年05期
- Page:
- 95-102
- Research Field:
- 汽车与机械工程
- Publishing date:
Info
- Title:
- Cycle variations characteristic of high pressure common rail diesel engine at idle condition
- Author(s):
- HAN Zhi-qiang; REN Chuan-jian; ZENG Dong-jian; WANG Hai
- 1. School of Automobile and Transportation, Xihua University, Chengdu 610039, Sichuan, China; 2. Sichuan Research Center of Clean Automotive Engineering and Technology, Xihua University, Chengdu 610039, Sichuan, China
- Keywords:
- automobile engineering; diesel engine; idle; cyclic variation
- PACS:
- U464.173; TK421.2
- DOI:
- -
- Abstract:
- Idle condition might makes bad fuel atomization, uneven mixed gas concentration distribution, larger cycle fluctuations, and poor economy and emissions because of its low speed, less intake charge, more residual gas coefficient, low cylinder mean temperature and weak air movement. Therefore, the research of idle cycle fluctuation characteristics of turbocharged diesel engine is important for the optimization of idle speed control strategy, and improvement of the stability performance of idle diesel engine. To examine the influence of different injection pressure, injection timing and coolant temperature on cycle-to-cycle variation at idle condition, an experimental study was conducted on a 4-cylinder water-cooled high-pressure common rail diesel engine. The cycle fluctuation of the engine was evaluated by measuring the maximum cylinder pressure, the corresponding crank angle, the cycle fluctuation rate of maximum pressure rise rate, and the fluctuation ratio of the continuous cycle. The results show that at idle condition, the combustion can be advanced and the coefficient of variation (CoV) of maximum cylinder pressure (Pmax) and its position (φmax) increase from 2.9% and 0.2% to 4.2% and 1.9% respectively with the increase of injection pressure. The CoVPmax falls from 3.2% to 2.3% and then increases to 3.5% with the increase of injection timing from -2°ATDC to -14°ATDC. The experimental results also show that the cyclic variation is sensitive to temperature changes. When the cooling water temperature increases from 30 ℃ to 50 ℃, the maximum pressure fluctuation rate and cycle fluctuation rate of the cylinder decrease sharply, but when the cooling water temperature increases further, the idle cycle fluctuation is weakening gradually.
Last Update: 2016-10-06