DIRECTION OF THE INJECTION PROCESS DURING THE USE OF FUEL MIXTURES THAT INCLUDE FUEL OF BIOLOGICAL ORIGIN IN MARINE DIESEL ENGINES

Abstract

Consider the issue of directing the injection process during the use of fuel mixtures that include fuel of biological origin in marine diesel engines. It was determined that during the use of fuel mixtures, which include biofuel, there is a change in the operating parameters of the diesel engine, primarily the maximum combustion pressure, the temperature of the exhaust gases, and the emission of nitrogen oxides with the exhaust gases. In order to prevent this phenomenon, as well as to improve the environmental friendliness of the ship's diesel engine and reduce mechanical and thermal loads, it is proposed to perform a reconfiguration of the high-pressure fuel equipment, which consists in changing the fuel injection advance angles. Experiments that confirmed this assumption were performed on marine diesel engines 6DK-20e Tier II Daihatsu Diesel, which were operated on a fuel mixture that included petroleum fuel RMA10 and biofuel FAME 99.9, which is a mixture of various methyl esters of fatty acids. Experiments were performed for two types of fuel mixtures: fuel RMA+10% biofuel FAME 99.9 and fuel RMA+15% biofuel FAME 99.9. This composition of the mixtures ensured the maximum reduction of the emission of nitrogen oxides and carbon dioxide with exhaust gases and the minimum increase in specific fuel consumption. The necessity of reducing the advance angle of fuel injection in the case of using fuel mixtures containing biological fuel in marine diesel engines has been experimentally proven. At the same time, it was found that reducing the fuel injection advance angle from -14° to -9° for different operating modes and different fuel mixture composition ensures a decrease in the maximum combustion pressure from values of 9.1–15.8 MPa to values of 8.7.- 15.5 MPa ( by 1.9–.4.4 %) and a decrease in the emission of nitrogen oxides with exhaust gases from the values of 6.19–7.14 kg/(kW·h) to the values of 5.93–6.61 kg/(kWh) – by 4.2–7.4 %. It was also established that increasing the fuel injection advance angle from -14° to -20° for different operating modes and different fuel mixture composition leads to an increase in the maximum combustion pressure to values of 9.5–16.1 MPa ( by 1,9–4.4 %) and an increase in the emission of nitrogen oxides with exhaust gases from values to values of 7.10–7.70 kg/(kW·h) – by 7.1–7.7 %. Determining the optimal fuel advance angles is achieved experimentally and contributes to ensuring the operational performance of marine diesel engines.