• Energy Research

This article considers the issues of ensuring operational performance and environmental sustainability of marine diesel engines by using biodiesel fuel. This research was conducted on 5S60ME-C8 MAN-B&W Diesel Group and 6DL-16 Daihatsu Diesel marine diesel engines, which are operated using RMG380 petroleum fuel and B10 and B30 biodiesel fuels. The efficiency of biofuel usage was assessed based on environmental (reduced nitrogen oxide concentration in exhaust gases) and economic (increased specific effective fuel consumption) criteria. It was found that the use of B10 and B30 biofuels provides a reduction in nitrogen oxide concentration in exhaust gases by 14.71–25.13% but at the same time increases specific effective fuel consumption by 1.55–6.01%. Optimum fuel injection advance angles were determined that ensure the best thermal energy, economic and environmental performance of diesel engines. The optimum angle of biofuel supply advance is determined experimentally and should correspond to the limits recommended by the diesel engine operating instructions. It has been proven experimentally that the use of biofuel increases the environmental sustainability of marine diesel engines by 13.75–29.42%. It increases the diesel engines environmental safety in case of emergency situations as well as accidental and short-term emissions of exhaust gases with an increased content of nitrogen oxides into the atmosphere phenomena that are possible in starting modes of diesel engine operation as well as in modes of sudden load changes. It is the increase in the environmental friendliness of marine diesel engines in the case of using biofuel that is the most positive criterion and contributes to the intensity of biofuel use in power plants of sea vessels.

The results of the research work on biofuel’s impact on the environmental and economic performance of marine diesel engines are presented. During the research, a fuel mixture was used that consisted of the diesel fuel RMA10 and FAME biofuel. The objective of the research was to determine the optimal concentration of biofuel mixed with diesel fuel. The research work was carried out on three of the same type of marine medium-speed diesel engine, 6N165LW Yanmar. One of the diesel engines only operated on diesel fuel, and the other two operated on a mixture of diesel fuel and 5–20% biofuel. During the experiment, the diesel engines operated at a load of 50–80% of the rated value. Experimentally, it was found that using biofuel improved the environmental friendliness of diesel engines: the emission of nitrogen oxides in exhaust gases was reduced by 8.7–23.4%, and the emission of carbon oxides in exhaust gases was reduced by 3.1–24%. However, when using biofuel, the economic efficiency of diesel operation decreased as the specific effective fuel consumption increased by 0.5–9.3%. The highest environmental efficiency was achieved when using a fuel mixture that included 10–15% biofuel in an 80% diesel load. In this case, the emission of nitrogen oxides was reduced by 21–23.5%, the emission of carbon oxides was reduced by 16.5–19.2%, and the magnification of the specific useful consumption of the diesel engine was 1–1.55%.