Partially-charged advanced low-temperature combustion in diesel engine: Progress and prospects

Stringent mandates relating to emission management forced scientists, engine manufacturers, and policymakers to have more tightly bound relationships aiming at the strategies of cleaner combustion and more efficient fuel use from internal combustion engine-based vehicles. Emerging as a promising solution, diesel engines based on the combustion of premixed-charge compression ignition (PCCI) and partially premixed combustion ignition (PPCI) showed prominent advantages for lowering NOx and PM emissions because a partially homogeneous air-fuel mixture, which is different from HCCI engines and diesel engines, is mostly formed and burnt in the premixed phase. In this review paper, the PCCI/PPCI combustion and their applications to real engines are thoroughly analyzed. Moreover, various injection strategies like injection pressure, injection timing, injection angle, and critical characteristics for approaching the PCCI/PPCI combustion modes including the numerical simulation and experiments are mentioned, and emission indicators and performance characteristics of engines based on PCCI/PPCI combustion modes are also discussed in details. Additionally, the role of fuel, exhaust gas recirculation, and engine loads in controlling the PCCI/PPCI combustion is scrutinized. Finally, the scenario for deploying and developing PCCI/PPCI engines in application to the real world is given out to move towards a brighter future with acceptable pollution and as-expected sustainability.