Investigation of the combustion process of activated fuel in an automotive diesel engine

BACKGROUND: Intensive development of the transport sphere and the extension of the fleet of tractors and cars, as well as the tightening of standards and requirements in the field of exhaust gas emissions have resulted in increased requirements for the combustion process. This problem can be solved by improving the working process in the engine by preheating the fuel to 300 °C in the high pressure fuel supply system. Under external thermal influence, the conditions of mixture formation are improved, an increase in the rate of preflame reactions and a positive change in the dynamics of the combustion process are observed. When potential energy of hydrocarbon molecules increases in the activated complex system, energy is redistributed among active molecules. Along with this, the rate coefficient of a chemical reaction increases due to the concentration of foci of hydrocarbon molecules that have reached the energy barrier.

The object of research is the process of diesel fuel combustion at preliminary external influence on it.

AIMS: The aim is to study the combustion process of a motor-tractor diesel engine upon fuel activation. Development of a scheme of individual phases of the activated diesel fuel combustion of depending on the temperature at heating.

METHODS: Theoretical study and analysis of the combustion process of thermally preprepared fuel for an automotive diesel engine. Theoretical determination of the dependence of the rate of formation and concentration of toxic components and dispersed particles on the rate constant of direct and reverse chemical reactions, as well as on the activation temperature of fuel at emission in exhaust gases.

RESULTS: The actual coefficient of molecular change of the working mixture increases when diesel fuel is activated. The rate of formation of total nitrogen oxides and hydrocarbons increases by 1.79% and 3.66%. The proportion of unburned carbon in the combustion process on activated fuel varies within ± (2…4) %.

CONCLUSIONS: Theoretically, a scheme for changing individual phases of the activated fuel combustion process by time and temperature has been developed. Fuel heating accelerates the pre-flame preparation in the liquid phase, shortens the duration of the rapid gorenje phase. The concentration of toxic indicators depends on the constant of the chemical reaction rate and the activation temperature of the fuel.