Numerical simulation of nitrogen oxide formation in dust furnaces

Abstract

Even though natural sources of air pollution account for over 50 % of sulphur compounds, 93 % of nitrogen oxide which are the most dangerous artificial anthropogenic sources of air pollution and primarily associated with the combustion of fossil fuel. Coal-fired thermal power plants and industrial fuel-burning plants that emit large quantities of nitrogen oxides (NО and NО2), solids (ash, dust, soot), as well as carbon oxides, aldehydes, organic acids into the atmosphere pollute the environment in majority. In the present work, a mathematical model and a scheme for calculating the formation of nitrogen oxide has been developed. Also, the dependence of the rate of release of fuel nitrogen from coal particles at the initial stage of gasification and content of volatiles has been obtained. The main regularities of the formation of NOx at the initial section of the flame in the ignition zone of the swirl burner flame during the combustion of Ekibastuz coal have been revealed. Modern environmental requirements for the modernization of existing and the creation of new heat and power facilities determine the exceptional relevance of the development of effective methods and constructions to reduce emissions of nitrogen oxides, sulfur oxides and ash to 200, 300, and 100 mg/nm3 at a=1.4. The dust consumption in all experiments was kept constant and amounted to 0.042 g/s, as well as with the results of calculating the thermal decomposition of the Ekibastuz coal dust, the recombination of atomic nitrogen into nitrogen molecules, and the kinetics of the formation of fuel nitric oxide.
 It was found that despite the presence of oxygen in Ekibastuz coal for gases Odaf=11.8 % in an inert atmosphere, nitrogen oxides are not formed

Research of the combustion process in the initial mixing section of the injection gas burner

“…In order to increase the efficiency of the use of gaseous fuel, new operational solutions are being sought in the field of fuel technology and control systems for combustion devices. Numerical modelling and the simulation of combustion processes provides an effective tool for obtaining quantitative results of basic torch parameters with reliable accuracy (Xue et al 2020;Wang et al 2022;Yuanshu et al 2022;Khabbazian et al 2022;Ongar et al 2022). There are enough examples in the literature for it to be expected that based on mathematical modelling, reliable data on the structure of the torch can be obtained (Ramos 1981;Kaufmann et al 2002;Bernardi et al 2003;Guo et al2019).…”