Calculation of the process of nitrogen oxides formation during combustion of methanol in the engine

Abstract

The developed method is based on a two-zone model and allows calculating the pressure and temperature (fresh mixture and combustion products), cycle indicators, as well as the current concentration of nitrogen oxides (NO) in the combustion chamber as a function of the crank angle. It can be used to evaluate the influence of parameters such as the beginning and duration of combustion, the composition of the mixture, heat loss from the gas to the walls, compression ratio, etc. on indicator indicators and output. In this model, the cylinder charge during combustion is divided into two zones: the zone of unburned mixture and the zone of combustion products. It is assumed that the fuel-air (unburned) mixture before and during the combustion process is homogeneous. The zone of combustion products at each moment of the cycle has a uniform composition and temperature. The combustion process is calculated according to the specified fuel burn-out law, taking into account the dissociation of the combustion products. The equilibrium concentrations of individual combustion products necessary to account for dissociation (CO and H 2) and the formation of NO (O 2, H 2, O) are determined by approximating polynomials.