Amirkabir University of Technology Amirkabir Journal of Mechanical Engineering 2008-6032 54 1 2022 03 21 Study of The Effect of Wall Temperature and Oxidant Structure on Temperature Distribution and NO Emission in Non-Premixed Combustion Furnace Study of The Effect of Wall Temperature and Oxidant Structure on Temperature Distribution and NO Emission in Non-Premixed Combustion Furnace 249 266 4504 10.22060/mej.2021.19792.7114 FA Amin Tajdani PhD Student of Kashan University, Kashan, Iran Seyed Abdolmehdi Hashemi Esmaeil Ebrahimi Fordoei Faculty of Mechanical Engineering , Tarbiat Modares University Journal Article 2021 03 26 The aim of this study was to investigate the effect of the thermal condition of furnace wall and oxidant structure on NOx emission and thermal conditions inside the non-premixed combustion furnace. For this purpose, non-premixed combustion furnace simulations have been performed using OpenFOAM software. Standard k-ε turbulence model, modified eddy dissipation concept combustion model, and discrete ordinates radiation model are used in numerical simulations. In order to analyze the results of numerical simulations, chemical calculations using a well stirred reactor have also been considered. According to the results, increasing the furnace wall temperature to reach thermal insulation conditions leads to a significant increase in the average and maximum temperature inside the combustion chamber and transfers the combustion regime from flameless to high temperature. In addition, the replacement of carbon dioxide with nitrogen will be accompanied by a decrease in the combustion temperature due to physical and chemical differences between the two species. According to the results, increasing the wall temperature, despite reducing the heat loss, leads to an increase in NO_x in the high temperature combustion regime. The use of carbon dioxide instead of nitrogen in an oxidizer can be considered as a way to reduce heat loss while reducing NO_x emission from the non-premixed combustion furnace. The aim of this study was to investigate the effect of the thermal condition of furnace wall and oxidant structure on NOx emission and thermal conditions inside the non-premixed combustion furnace. For this purpose, non-premixed combustion furnace simulations have been performed using OpenFOAM software. Standard k-ε turbulence model, modified eddy dissipation concept combustion model, and discrete ordinates radiation model are used in numerical simulations. In order to analyze the results of numerical simulations, chemical calculations using a well stirred reactor have also been considered. According to the results, increasing the furnace wall temperature to reach thermal insulation conditions leads to a significant increase in the average and maximum temperature inside the combustion chamber and transfers the combustion regime from flameless to high temperature. In addition, the replacement of carbon dioxide with nitrogen will be accompanied by a decrease in the combustion temperature due to physical and chemical differences between the two species. According to the results, increasing the wall temperature, despite reducing the heat loss, leads to an increase in NO_x in the high temperature combustion regime. The use of carbon dioxide instead of nitrogen in an oxidizer can be considered as a way to reduce heat loss while reducing NO_x emission from the non-premixed combustion furnace. https://mej.aut.ac.ir/article_4504_4ac93818f5882e3eb0ce60d96f3986d6.pdf