Research on Influence of Valve Response on Transient Combustion and Emission Performance for Non-throttle Engine Fueled with E10 |
You Zhou1,2,3, Fangxi Xie2,3, Boqiang Zhang1, Peng Sun1, Xun Zhang1, Zechen Yao1, Xianglong Meng2,3 |
1School of Mechanical and Electrical Engineering, Henan University of Technology, Zhengzhou 450000, China 2State Key Laboratory of Automotive Simulation and Control, Jilin University, Changchun 130000, China 3College of Automotive Technology, Jilin University, Changchun 130000, China |
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Received: May 21, 2024; Revised: June 14, 2024 Accepted: June 18, 2024. Published online: October 18, 2024. |
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ABSTRACT |
Non-throttle engine can greatly improve engine thermal efficiency and has considerable application prospect, but combustion and emission performance under transient conditions need to be clarified. This test studied the effects of valve lift response on non-throttle combustion and emissions performance under transient conditions by test and ANOVA. The results showed that for non-throttle engine, there shows a un-synchronization phenomenon between valve lift and in-cylinder combustion. When switching from high IMEP to low IMEP, faster valve control motor speed shortened excess air coefficient and cylinder pressure stability cycles. However, when switching from low IMEP to high IMEP, faster valve control motor speed caused cylinder pressure and IMEP deteriorated and misfire trend seriously. Especially, when excess air coefficient fluctuated higher than 1, NOx emissions deterioration occurred. The fluctuation of intake and exhaust valve lift under transient conditions led to fluctuation of excessive air coefficient, i-EGR rate, and other boundary conditions. Excess air coefficient dominated cylinder pressure and IMEP under light load, but the proportion of i-EGR rate and initial reaction temperature increased to 50% gradually with load increasing. I-EGR rate and excess air coefficient were important boundaries for NOx emission, but influence of i-EGR rate on HC and CO emission was limited. |
Key Words:
Non-throttle engine · Transient condition · Variable valve lift · NOx emissions · Ethanol fuel |
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