Dual main injection strategy GCI mode improves fuel economy

Exploring advanced combustion mode with high efficiency and low emissions has been the dream of the next generation of researchers. Conventional diesel engines have high compression ratios, resulting in 35%-45% thermal efficiency, but diffuse combustion.

The properties of diesel generate NO_X And soot emissions are high. Gasoline Compression Ignition (GCI) is an advanced combustion mode in the field of internal combustion engines that combines the advantages of high efficiency of diesel engines and low emissions of gasoline engines. Although GCI mode can achieve high efficiency while maintaining low NO_X and soot emissions, GCI combustion still faces problems such as high maximum pressure rise ratio (MPRR) and combustion degradation at high loads.

The research group of Yong QIAN of Shanghai Jiao Tong University proposes a new method to improve the problems of combustion decay of GCI mode at high MPRR and high loads. A new method called double main-injection (DMI) technique used two direct injectors for simultaneous main injection. By comparing the TMI strategy with the single main-injection (SMI) strategy and conventional diesel combustion at high loads, ① found that the simultaneous main-injection of two direct injectors can achieve rapid fuel delivery and control of the fuel layer in TMI. method, ② exhaust gas recirculation has a significant effect on combustion and emissions of DMI mode, ③ DMI strategy achieves more efficient and stable combustion of GCI mode, ④ DMI strategy can relieve the need of GCI.

Improves injection pressure and problems like high MPRR and combustion collapse.

The proposed new algorithm-DMI strategy can improve fuel economy and reduce MPRR at high loads, and it is more important for GCI mode. The findings were published in Frontiers in Energy on January 10, 2023.