全部 标题 作者
关键词 摘要

OALib Journal期刊
ISSN: 2333-9721
费用:99美元

查看量下载量

相关文章

更多...
-  2019 

Improving diesel engine efficiency at high speeds and loads through improved breathing via delayed intake valve closure timing

DOI: 10.1177/1468087417743157

Keywords: Variable valve actuation,intake valve modulation,dynamic charging,volumetric efficiency,fuel economy

Full-Text   Cite this paper   Add to My Lib

Abstract:

Valve train flexibility enables optimization of the cylinder-manifold gas exchange process across an engine’s torque/speed operating space. This study focuses on the diesel engine fuel economy improvements possible through delayed intake valve closure timing as a means to improve volumetric efficiency at elevated engine speeds via dynamic charging. It is experimentally and analytically demonstrated that intake valve modulation can be employed at high-speed (2200?r/min) and medium-to-high load conditions (12.7 and 7.6?bar brake mean effective pressure) to increase volumetric efficiency. The resulting increase in inducted charge enables higher exhaust gas recirculation fractions without penalizing the air-to-fuel ratio. Higher exhaust gas recirculation fractions allow efficiency improving injection advances without sacrificing NOx. Fuel savings of 1.2% and 1.9% are experimentally demonstrated at 2200?r/min for 12.7 and 7.6?bar brake mean effective pressure operating conditions via this combined strategy of delayed intake valve closure, higher exhaust gas recirculation fractions, and earlier injections

Full-Text

Contact Us

service@oalib.com

QQ:3279437679

WhatsApp +8615387084133