Research on Combustion and Emissions of RCCI Engine

The RCCI (Reaction Control Compression Ignition) engine achieves very high thermal efficiency and very low NOx and low PM emissions. By mixing two fuels with different cetane numbers, reactive stratification occurs in engine cylinder to achieve reactive combustion stratification. And the fuel in the cylinder can provide combustion efficiency of the engine and reduce emissions of the exhaust. LRF (low cetane number) is injected into the cylinder after being premixed, and the HRF (high cetane number) affects pressure rise rate through segmented combustion and heat release rate, such that the segmented fuel rate of the fuel and the heat release rate can be adjusted by the two fuel injection concentrations and injection times. The CR and geometry of piston bowl of engine play an important role in this. This paper reviews the segmentation performance and injection conditions of RCCI engines and summarizes the research progress in changing combustion processes, including changes to the internal parameters of RCCI engines, includes the use of alternative fuels and the use of low-reactivity cetane number improvers. And the effect of fuel ratios with highly reactive fuels, fuel reaction strategies for different degrees of reaction, compression ratio, EGR engine performance and emission rate, and geometry of the piston bowl surface.