A study on the spark discharge effect on ignition and emission characteristics of LPG engine using RCEM

Abstract

A study on the spark discharge effect on ignition and emission characteristics of LPG engine using RCEM Department of Mechanical Engineering Cahyani Windarto A spark ignition strategy in compression ignition has been considered to achieve high performance and reduce pollutant emissions of direct injection engines. It is challenging to optimize the operating parameters of spark discharge duration effect of the internal combustion engine. The potential improvement in in-cylinder performance and emission characteristics of CI engines fueled with gasoline, diesel and propane mode was investigated in an experimental and simulation series in this study. Analyzing the novel technique of liquid fuel injection is worthwhile given the potential for high-efficiency compression ignition engines to achieve marine diesel-like, high-efficiency combustion in a RCEM research engine. The spark ignition energy depends on the discharge current and the spark discharge duration. Since propane has a low cetane number, spark plug operating is provided to achieve reliable ignition. However, the respective roles of both on the rapid compression and expansion machine (RCEM) running with spark ignition and gasoline direct injection in- cylinder pressure have not been fully investigated. 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. Three spark ignition strategy ranging from 50 mA up to 200 mA is applied to enhance the ignition discharge energy according to six selected cases of ignition timing duration (0.7 ms, 1.0 ms, 2.0 ms, 3.0 ms, 4.0 ms, and 5.0 ms). 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. Finally, the establishment of a compression ignition engine combined with spark energy discharge might contribute to faster plasma formation, as well as expose the kernel development to a wider range of spark duration. Keywords: RCEM; spark discharge energy; computational fluid dynamics; in-cylinder performance; direct injection; propane; emission.