Research Of Marine Diesel Engine Combustion Mechanism And Emission Simulation

Nowadays, Marine environmental pollution has become a serious problem, which is mainly influenced by the pollutants of diesel engine. The supplement of "MARPOL Convention" has strict restrictions on emissions of nitrogen oxides and sulfur oxides. Every country takes all kinds of effective measures to cope with pollution situation. By combustion and emission simulation, we research cylinder working process and predict the discharge of pollutants generation, which could help to improve the comprehensive performance and reduce the emissions.This article is a theoretical analysis about formation mechanism of nitrogen oxides and sulfur oxide, which are produced by internal combustion engine. On the basis of pollutant molecule formed, we could analyze the nitrogen oxides and sulfide formation mechanism through quantum chemical theory and calculation chemical methods. What's more, we could also optimize the various molecular configurations, determine the transition state, look for stable point, simplify the intermediate links of the reaction mechanism, and determine various chemical reaction kinetics parameters. With the help of above procedures, we could build the formation models of the nitrogen oxides of sulfur oxides which suit the Marine diesel engine simulation calculation on the basis of extended HB model.Importing a multidimensional combustion simulation program, this paper not only applies related turbulent combustion model and combustion chemical kinetic model, etc, but also modifies its original model of nitrogen oxides, and adds sulfide formation models. By debugging the program and taking the simulations, we got numerous data of cylinder flow field and average performance curve, and comparatively analyzed the calculated result and experimental data, the new model for reference to verify the accuracy and feasibility. On the basis of the new model, this study also calculates and analyzes the different performances of combustion process and emission performance by changing the working parameters such as the load, swirl ratio, and oil injection time.