Mathematical model of emissions of harmful substances from automotive and tractor engines under operating conditions

BACKGROUND: One of the features of improving the performance of diesel engines is the analytical evaluation method, as well as the analysis of operation in field conditions when using various types of fuel. The studied agricultural machinery operates at various speed load modes of their engines. Mathematical modeling of working processes that link output variables with input effects allows determining the emissions of harmful substances from automotive and tractor engines under operating conditions. AIM: Compilation of a mathematical model of emissions of harmful substances from automotive and tractor engines under operating conditions. METHODS: Experimental studies were carried out in accordance with the requirements of GOST 14846-2020 (Automotive engines. Bench test methods) and GOST 18509-88 (Tractor and combine diesel engines. Bench test methods). The main operational factors influencing the power, environmental and economic performance of engines running on water-fuel emulsion were analyzed at the Irkutsk State Agrarian University named after A.A. Ezhevsky and the Buryat State University named after D. Banzarov. During the experiments in the field, the following factors were found: a decrease in torque, a decrease in diesel power due to fluctuations in the resistance moment on the engine by an average of about 10% for each of the above indicators. This indicates a violation of the cyclic fuel supply, mixing and combustion processes, which negatively affects technical, economic and environmental indicators. RESULTS: Experimental data were obtained for various indicator powers corresponding to fluctuations in the cyclic fuel supply for operating conditions. Under operating conditions, soot emissions ranged from 0.11 to 0.32 times; NOx emissions ranged from 2.94 to 5.62 times, and when adding a 30% methanol additive, soot emissions ranged from 0.02 to 0.32 times; NOx emissions ranged from 2.5 to 2.2 times. The calculated indicators show a satisfactory correlation to the theoretical studies, ranging within up to 5%. Therefore, according to the proposed method, it is possible to determine the emissions of harmful substances of diesel engines under operating conditions. An analysis of the dynamic properties of fuel supply under operating conditions is carried out and equations for the relationships of output coordinates with input ones are presented. Under field experiment conditions, a decrease in torque and diesel power with significant fluctuations in crankshaft velocity were found. Emissions of harmful substances of diesel engines were determined by calculation. CONCLUSION: An integrated approach to the study of the influence of alternative fuels and operating conditions on emissions of harmful substances in diesel engines is crucial for development of effective solutions to reduce their negative impact on the environment.