An Experimental Research The Effect of The Pressure in High-Pressure Pipelines on Exhaust Emissions of The Fishing Vessels' Main Diesel Engines

When the pressure in the high-pressure pipelines of the diesel engine’s fuel injection system decreases, the injection pressure at the injector decreases accordingly, making the formation of the fuel-air mixture uneven, which will reduce the efficiency of the fuel-air mixture. Low heat and combustion temperature, cause increased soot emissions. Therefore, it is necessary to determine the level of pressure reduction in the high-pressure pipelines during engine operation and compare it to the initial state (standard state) given by the manufacturer. Thereby giving measures to repair and maintain the fuel injection system, which will help improve combustion efficiency and reduce environmental pollution, and at the same time prevent problems with the diesel engines used as the main engine of fishing boats. In this paper, the experimental results on 4CHE-Yanmar diesel engines are presented, showing that: When the pressure in the high-pressure pipeline is reduced by up to 14% compared to the initial state of the manufacturer, the soot emissions increased by 5%, NOx emissions decreased by about 6%.