Experimental investigation of the effects of the high cetane number fuel injection on the performance of a direct injection low-temperature combustion engine

In recent decades, low temperature combustion engines have been the focus of researchers as an effective strategy to achieve the optimal combustion model. In this method of combustion, initially, the fuel with high octane is sprayed in the inlet manifold and then another fuel with a high cetane number is injected into the combustion chamber at a different time. Combustion in reaction-controlled compression ignition engines does not use direct control tools and depends on the reactions' initial conditions and chemical kinetics. Considering the importance of ignition timing and its control in low-temperature combustion engine performance, in this study, using the control variables of ignition delay, fuel injection time and maximum pressure inside the cylinder, along with the fuel injection system as the ignition control operator, to the experimental investigation of the performance of a direct injection low temperature combustion engine has been discussed. The results show that the injection time of diesel fuel inside the cylinder is one of the most important factors influencing the performance and efficiency of the engine. For low methane injection rate (15 slm), with increasing delay in pilot fuel (diesel) injection time, the value of the maximum heat release rate and specific fuel consumption decreased, while the mean effective pressure and gross indicator efficiency increased. By controlling the reactivity of the mixture and the fuel injection time with more reactivity, it is possible to achieve the appropriate ignition time, which indicates the importance of the fuel injection time as an essential control parameter in the ignition control of a low-temperature engine. In general, the methane rate has a secondary effect on ID compared to SOI.