Experimental and modeling analysis of multiple-injection strategies with B20 operation in a CRDI engine

Biodiesel blend (B20) is the most widely adopted renewable alternative for diesel and their production feedstock varies significantly concerning geographic location and availability. Further, modern diesel vehicles involve an electronic injection system with varying multiple injection schedules for light and heavy-duty applications. Thus, testing a new feedstock with an optimum injection schedule is cumbersome and time-consuming. Thus, the current work involves a combined study of engine experiments with phenomenological combustion and emission modeling to ascertain the nature of B20 operation in an automotive LDD CRDI Engine. The twin-cylinder engine was experimentally tested with multiple-injection strategies, viz. single and triple with diesel and waste cooking biodiesel blend (B20) under three injection pressures. It is observed that the multiple-injection reduces nitric oxide (NO) and soot emissions simultaneously. The increase in NO emission with B20 can be mitigated to diesel level with the help of multiple-injection. The soot emission from B20 is significantly less than diesel at both single and triple injection cases. The model is validated with a wide range of experimental results and a parametric study has been carried out to explore the effect of operating parameters such as fuel quantity and the dwell period between the injection pulses for B20 fuel. The parametric investigations recommend a suitable pilot fuel quantity and longer dwell between the pilot and main injection for NO reduction, and a small quantity of post fuel and medium dwell between main and post-injection for achieving soot reduction without penalty on mean effective pressure.

Automated summary

The study investigates the operation of B20 in automotive engines through engine experiments and combustion emission modeling, concluding that multiple injections can reduce NO and soot emissions, with significantly lower soot emissions for B20 compared to diesel.