The use of ethanol in diesel engines.

The need to replace traditional petroleum motor fuels with alternative fuels is becoming more and more urgent every year. Special attention is paid to alcohol fuels, as they are renewable energy sources. In addition to being renewable energy sources, alcohol fuels have a number of positive qualities, including reducing harmful emissions into the atmosphere. The significant disadvantages of alcohol fuel include the low value of the cetane number and the insufficient efficiency of the ignition process. As a technical solution to this drawback, mixed fuel is used. Diesel fuel with a high cetane number is used as a starting dose, and alcohol is used as the main fuel. A positive fact when using alcohol as a fuel is the temperature of the working fluid reduced by 100...200 degrees during combustion in the diesel cylinder due to the lower heat of combustion of alcohol in comparison with diesel fuel and, as a result, less thermal effects on the elements of the cylinder and piston. The power of the diesel engine can be increased due to an increase in the water vapor content in the combustion products. Operation when expanding the gas in the diesel cylinder is proportional to the gas constant of the working fluid. In the combustion products, the largest share is nitrogen N2 with a gas constant equal to R=296.9 kJ / kg, carbon dioxide CO2 has a gas constant of R=189 kJ/kg and water vapor H2O has a gas constant of R=461.9 KJ/kg. The physical meaning of the gas constant is that when cooled by one degree, a kilogram of the working fluid performs work numerically equal to the value of the gas constant. Consequently, with an increase in the proportion of water vapor in the combustion products, the operation of the diesel engine increases. [ABSTRACT FROM AUTHOR]