USE OF VEGETABLE OIL AS A FUEL IN A MEDIUM SPEED DIESEL ENGINE

Abstract

While being highly fuel-efficient, diesel engines are defined by relatively high emissions, which have a negative impact on people and the environment. In the future, most European countries plan to abandon the use of diesel engines after 2030. One way to use this type of engines is to convert them to alternative fuels from renewable energy sources, such as vegetable oils (rapeseed, sunflower and soya bean oils). A significant advantage of vegetable oils is that when they hit the ground, they break down in a couple of weeks. Sulfur oxides are virtually absent due to the small amount of sulfur in vegetable oils in the engine exhaust gases. Other environmental factors include reduced emissions of nitrogen oxides NOx, carbon monoxide CO, unburned hydrocarbons and carbon black C. However, it should be noted that the use of vegetable-based fuel involves problems related to fuel preparation, consideration of physical and chemical properties and proper engine operation and use of arable land for the cultivation of vegetable oils. The article presents the results of experimental studies to determine the effective performance of soybean oil, six cylinder, four-stroke supercharged diesel engine (26 – the diameter of the cylinder, cm; 34 – the piston stroke, cm) produced by "Pervomaiskdieselmash", which is a part of the stationary diesel generator (DGA-900) with the capacity of 900 kW. This diesel engine is with an undivided combustion chamber ("Geselman" type), gas turbine supercharging and intermediate charge air cooling. Soybean oil is more viscous and has better lubrication properties of conjugated vapors and engine components, as a result, the lifespan of the engine and high-pressure fuel pump increases by an average of 60%. However, more viscous soybean oil impairs fuel mixing, spraying and combustion. Starting qualities of the engine also deteriorate. On the other hand, as the temperature rises, the viscosity of soybean oil decreases sharply. The reasons which led to the emergence of the above-mentioned problems have been analysed. In addition, the features and advantages of the cogeneration power plant have been described, which makes it possible to obtain two forms of useful energy at the output such as thermal and electric. The use of cogeneration significantly increases the overall efficiency of the plant; it provides significant opportunities for efficient heat utilization and achieving maximum economic effect.