Efficient and clean combustion of intelligent charge compression ignition (ICCI) engine at low load conditions. (15th January 2023)

• Record Type: Journal Article
• Authors: Qian, Yong; Zhang, Yaoyuan; Mi, Shijie; Wu, Haoqing; Li, Zilong; Lu, Xingcai
• Is Part Of: Fuel. Volume 332(2023)Part 1
• Publication Date: 2023-01-15
• Subjects: Intelligent charge compression ignition (ICCI) -- Low engine loads -- Low-octane gasoline -- High efficiency -- Clean combustion; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2022.126002
• Languages: English
• ISSNs: 0016-2361

Abstract

Highlights: Intelligent charge compression ignition (ICCI) combustion under low loads were investigated. Effects of low-octane gasoline on combustion and emissions of ICCI were studied in detail. Efficient combustion can be expanded to IMEP of 4 bar with ITE higher than 50 %. NOx and particulate emissions maintained at low levels by optimizing engine control parameters. Abstract: The efficient and clean combustion of compression ignition (CI) engines under low load conditions has always been a challenge. Intelligent charge compression ignition (ICCI) mode has been proved to be able to effectively control the combustion phase and heat release rate which has great potential to improve engine efficiency. In this paper, the combustion and emission characteristics of ICCI mode under low load conditions with indicated mean effective pressure (IMEP) from 2 to 6 bar were explored. Commercial diesel was selected as high-reactivity fuel, commercial gasoline with the research octane number (RON) of 95 and three low-octane gasolines with RON of 85, 80 and 75 were tested as the low-reactivity fuel. The results show that by optimizing the fuel injection strategies and gasoline ratio, the indicated thermal efficiency (ITE) at IMEP of 6 bar could reach above 50 % with commercial gasoline as low-reactivity fuel. For IMEP of 2 bar, increasing intake air temperature and reducing intake pressure improved ITE up to 46 %. By taking RON85 as low-reactivity fuel, the ITE at IMEP of 4 bar could reach 51.4 % with the intake air temperature of 50 °C. NOx and particulate emissions were maintained at low levels under ICCI mode. Based on this study, the efficient and clean combustion of ICCI mode can be reached at IMEP of 4 bar with ITE higher than 50 %.