Dual fuel intelligent charge compression ignition (ICCI) combustion: Efficient and clean combustion technology for compression ignition engines

A brand-new combustion mode intelligent charge compression ignition (ICCI) was proposed to be expected for ultra-high efficiency and low emissions simultaneously. The introduce for conceptual model of ICCI mode aimed to realize flexible and controllable in-cylinder charge stratification fed by two complementary fuel, gasoline and diesel. To fulfill this unique dual-fuel combustion mode, two common-rail direct-injection systems were independently utilized on a modified single-cylinder engine, controlled by their own on-limits electronic control unit, respectively. Fundamentally experimental investigations on ICCI mode was conducted by the fuel ratio variation at 8 bar indicated mean effective pressure (IMEP). The experimental results showed that high indicated thermal efficiency close to 50% and low NOx emissions well below 0.12 g/kWh were simultaneously achieved at 85% gasoline ratio. Based on the optimal gasoline ratio, multi-injection strategies of ICCI mode can further improve thermal efficiency and emissions. Meanwhile, comparisons of ICCI with other combustion modes, including reactivity-controlled compression ignition (RCCI), G85 dual direct injection (DDI), G85, and G70 single direct injection (DI) strategies were carried out. In the similar operating conditions, ICCI combustion got better performance compared with other combustion modes, achieving about 2% increased indicated thermal efficiency in comparison to RCCI or DDI mode and near none NOx emissions compared with DI combustion. Prospectively, if it can be continually researched, ICCI has a large potential based on the further optimization in the future.