A comprehensive study of the effects of spark discharge duration on low-carbon combustion of high-pressure direct-injection propane: Factors affecting combustion, in-cylinder performance, and emissions

Abstract

To address emissions and fuel depletion, stringent emissions regulations encourage the replacement of diesel with clean and sustainable fuels. Propane has benefits over liquid fuels due to its advantageous chemical and physical properties, such as low carbon number in the fuel component and no fuel evaporation problems. The effects of spark release duration on propane direct injection were studied using experiments and simulation on a modification head of large-bore RCEM using three spark ignition strategies. The validated model CFD was applied to study the combustion and emission of propane as well as the spatial distribution of propane in the research engine. The main objective was to determine how high-pressure direct injection of propane can increase the efficiency of CI engines and reduce particulate and standard emissions. Data analysis revealed that propane releases heat more gradually than diesel fuel. However, the steady burning of DI propane offered extra benefits, such as improved combustion rate, which affected exhaust gas production. The emissions reduction was realized with DI-propane combustion compared to diesel combustion. Propane produces fewer particulates than diesel. THC and NOx emissions from diesel vehicles were 1.8% lower and 32.3% higher, respectively, than propane combustion. It is feasible to decrease NOx, particulate, and unburned fuel pollutants while maintaining CO2 emissions at levels comparable to a diesel engine. Both the onset of propane injection and the length of ignition timing have been shown to be optimum factors in emissions and performance. As the spark duration advances, the temperature in the cylinder increases, leading to a heat release peak resulting from combustion of residual fuel near the cylinder liner and in the gap area.