Experimental Study on the Effect of Load and Air+gas/fuel Ratio on the Performances, Emissions and Combustion Characteristics of Diesel-LPG Fuelled Single Stationary CI Engine

Abstract

Abstract Due to the issue of the combustion stability when using natural gas and the problem of knocking when using both natural gas and hydrogen, Liquefied Petroleum Gas (LPG) is then a good candidate to use for the dual fuel concept since it’s been proven to be a good solution to limit the pollutants and the excessive use of fossil resources. In this paper, the effect of load as well as the Air + Gas/fuel ratio on the performance, emission, and combustion characteristics of a dual fuel diesel-LPG engine, single-cylinder, four-stroke, direct injection diesel engine with a rated power of 3.5 kW at a speed of 1500 rpm has been carried out. Experiments have been performed in dual fuel mode for a range of load from 0 to 12 kg and a range of mass flow of LPG from 1 to 5.5 L/min, and the results were compared with those obtained from the single fuel mode. Results show that dual fuel mode gives better performances and fewer pollutants than single fuel mode and the highest performances, as well as the fewest pollutants in the dual fuel mode, were observed regardless of the load for the mass flow of LPG of 5.5 L/min. Brake thermal efficiency, indicated thermal efficiency, and mechanical efficiency increased by 32.97%, 60.4%, and 16.66% respectively when we move from the single fuel mode to the dual-fuel mode. The smoke, the carbon monoxide, and the NOx decreased by 62.4%, 3381 ppm, and 31.8 ppm respectively when we move from the single fuel mode to the dual-fuel mode. The net heat release rate and the cylinder pressure (the peak) were also evaluated and were higher at 5 L/min in the dual-fuel mode. And, no knocking came up during this research as compared to natural gas or hydrogen dual-fuel engines.