Analysis of Characteristics of CI/HCCI Chemical Combustion Mode Switching of Automotive Engine

• Main Author: Mengxiong Lu
• Format: Article
• Language: English
• Published: AIDIC Servizi S.r.l. 2017-12-01
• Series: Chemical Engineering Transactions
• Online Access: https://www.cetjournal.it/index.php/cet/article/view/903

In view of the problems appearing in cylinder average index pressure and the operating smoothness in the direct switching process of CI/HCCI chemical combustion mode in the cylinder of diesel engine, the injection compensation measures are drawn up for CI/HCCI direct switching to improve the average index pressure fluctuation, and the influence of injection compensation coefficient, transitional cycle number, fuel injection quantity and other parameters on CI/HCCI chemical combustion mode switching process analyzed. The conclusions are as follows. The CI/HCCI chemical combustion mode switching in the cylinder will lead to slow heat release in the cylinder, resulting in higher IMEP fluctuation ratio. The IMEP fluctuation ratio is the highest when the HCCI mode of the lower load zone is switched to the CI mode. The first cycle of cylinder using fuel injection compensation can improve the stable operation of the engine. IMEP fluctuation ratio is the lowest when fuel injection compensation coefficient is 1.06. The IMEP fluctuation ratio is the lowest, when the number of transition cycles is 2-3, as the fuel injection slightly lower than the linear decrease can improve the operating smoothness, and effectively reduce the emissions of NOx and particulates in tail gas.