Thermodynamic analysis of diesel engine ignition delay under low load conditions

In recent decades, renewable energies (e.g., wind and solar) were introduced to reduce the dependency of diesel generation in remote areas and islands power systems. However, diesel generation cannot be eliminated entirely because of the uncertainty and intermittent of renewable sources. In this regards, low load diesel operation (below 30% of maximum rated power) is considered to achieve highest possible penetration of renewable energy in the hybrid (e.g., renewable diesel) power system for isolated locations. Ignition delay (ID) is one of the key parameters to affect engine response and performance in the power generation sectors. This study investigated the diesel engine ignition delay for different load operations from 15% to 100% under different engine speed ranging from 1500 rpm to 2100 rpm. From this analysis, it was found that ignition delay time increased with a decrease in engine load and decreased with an increase in engine speed. The results showed that at 15% and 25% loading conditions ignition delay times are 1.16 and 0.98 ms for 1500 rpm, 0.98 and 1.07 ms for 1800 rpm, and 1.10 and 0.92 ms for 2100 rpm engine speed operation. These results indicate that the change of engine load and speed did not significantly affect ignition delay.