A methodology for regulating fuel stratification and improving fuel economy of GCI mode via double main-injection strategy  

作　　者：Haoqing WU Yaoyuan ZHANG Shijie MI Wenbin ZHAO Zhuoyao HE Yong QIAN Xingcai LU 

机构地区：[1]Key Laboratory for Power Machinery and Engineering of the Ministry of Education,Shanghai Jiao Tong University,Shanghai 200240,China

出　　处：《Frontiers in Energy》2023年第5期678-691,共14页能源前沿（英文版）

基　　金：supported by the National Key R&D Program of China(Grant No.2022YFE0100100).

摘　　要：Gasoline compression ignition(GCI)combustion faces problems such as high maximum pressure rise rate(MPRR)and combustion deterioration at high loads.This paper aims to improve the engine performance of the GCI mode by regulating concentration stratification and promoting fuel-gas mixing by utilizing the double main-injection(DMI)strategy.Two direct injectors simultaneously injected gasoline with an octane number of 82.7 to investigate the energy ratio between the two main-injection and exhaust gas recirculation(EGR)on combustion and emissions.High-load experiments were conducted using the DMI strategy and compared with the single main-injection(SMI)strategy and conventional diesel combustion.The results indicate that the DMI strategy have a great potential to reduce the MPRR and improve the fuel economy of the GCI mode.At a 10 bar indicated mean effective pressure,increasing the main-injection-2 ratio(Rm-2)shortens the injection duration and increases the mean mixing time.Optimized Rm-2 could moderate the trade-off between the MPRR and the indicated specific fuel consumption with both reductions.An appropriate EGR should be adopted considering combustion and emissions.The DMI strategy achieves a highly efficient and stable combustion at high loads,with an indicated thermal efficiency(ITE)greater than 48%,CO and THC emissions at low levels,and MPRR within a reasonable range.Compared with the SMI strategy,the maximum improvement of the ITE is 1.5%,and the maximum reduction of MPRR is 1.5 bar/°CA.

关 键 词：gasoline compression ignition injection strategy fuel stratification high efficiency high load 

分 类 号：TK4[动力工程及工程热物理—动力机械及工程]