Experimental study on the effect of load and air+gas/fuel ratio on the performances, emissions and combustion characteristics of diesel–<scp>LPG</scp> fuelled single stationary ci engine

Abstract

Abstract Due to the issue of 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 has been proven to be a good solution to limit the pollutants and the excessive use of fossil resources in the aim to support and advance the African Union's and UN's sustainable development goals. 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 loads from 0 to 12 kg and a range of volume 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 the dual‐fuel mode gives better performance and fewer pollutants than the single‐fuel mode. For example, at low load, Brake thermal efficiency, the indicated thermal efficiency, and mechanical efficiency increased by 83.79%, 24.36%, and 41.77%, respectively, and by 57.48%, 19.84%, and 24.37% at high load when we moved from the single‐fuel mode to the dual‐fuel mode. The smoke, carbon monoxide, and NO x decreased by 24.3%, 94.2%, and 96.2% respectively at low load and by 62.3%, 89.8%, and 91.4% at high load. And, no knocking came up during this research compared to natural gas or hydrogen dual‐fuel engines.