Analysis of the Effectiveness of the Use of Nitrogen Oxide Reducing Agent of Exhaust Gases of Diesel Engines

The relevance of the article is due to the need to radically improve the environmental performance of automobile diesels. The most significant gaseous toxic component of spent diesel engines are nitrogen oxides. The mechanisms and models of nitrogen oxides formation in the diesel combustion chamber are considered. The analysis of methods for reducing the emission of nitrogen oxides with diesel exhaust gases has been carried out. The most effective method of their purification from nitrogen oxides is the use of SCR technology, in which an aqueous urea solution is supplied to the diesel exhaust system. At a temperature of about 130 °C, urea decomposes into ammonia and carbon dioxide. Ammonia released from urea reacts with nitrogen oxides of exhaust gases, reducing them to nitrogen. A method for calculating the urea supply to the diesel exhaust system has been developed. Tests of the YAMZ-6566 diesel engine equipped with the SCR system were carried out. With an excess urea ratio of 1.03, the efficiency of the SCR system ranged from 89 to 100 %, depending on the operating mode of the diesel engine.