Results in Engineering (Dec 2023)
Experimental study of triple fuel physiognomies on LDRCCI diesel engine combustion
Abstract
Environmental deterioration and the current energy crisis are the driving factors for better combustion technologies and renewable, clean energy sources. To improve engine combustion efficiency and reduce emissions, numerous low-temperature combustion techniques have been investigated. Among all low-temperature combustion engines, the reactivity-control compression ignition (RCCI) engine is the most recent and preferred one to reduce PM and NOx emissions to govern the ignition and combustion processes. However, it has not yet revealed the optimal solutions. The port injection is used for the secondary fuel system to manage emissions, in-cylinder charge reactivity, and combustion phasing during RCCI operation. A triple-fuel RCCI engine that burns a port-injected blend and direct-injected diesel fuel has been experimentally investigated in this work. The G5E15-RCCI engine was observed to run at a maximum cylinder pressure and HRR of 90.76 bar, and 63.02J/deg respectively at 3000 rpm while for the baseline fuel they are much lower at 58.69 bar and 11.8J/deg respectively with the speed being 2500 rpm. The NOx and CO2 emissions were at their lowest levels with the engine running on G5E15, whereas they were at their highest for the engine running on baseline mode. Under G5E15-RCCI engine operation, CO and UHC increase as usual while G10E10-RCCI emits a minimum that can be taken as a novel finding in which CO and HC emission reduction was demonstrated with RCCI in this study. The brake power in all experiment cases was observed as approximately the same with slight increases for G10E10 at speeds greater than 2400 rpm. The maximum engine brake torque occurred in the speed range of 2000-2600 rpm for G10E10 and in the narrower range of 2200- 2400 rpm for the G5E15 port-injected blend. Better brake thermal efficiency was noted for the engine running on baseline fuel in the speed range of 2200-2600 rpm while being higher for the engine running on G5E15 RCCI mode at 2800 and 3000 rpm as such.
