Initiation of Combustion of Coal Particles Coated with a Water Film in a High-Temperature Air Flow
A. V. Zakharevich1, G. V. Kuznetsov1, V. V. Salomatov2, P. A. Strizhak1, S. V. Syrodoi1
1Tomsk Polytechnical University, Tomsk, 6340050 Russia
2Kutateladze Institute of Thermophysics, Russian Academy of Sciences, Novosibirsk, 630090 Russia
Keywords: водоугольное топливо, зажигание, тепло- и массоперенос, термическое разложение, испарение, водяная пленка, время задержки зажигания, время испарения, water-coal fuel, ignition, heat and mass transfer, thermal decomposition, evaporation, water film, ignition delay time, evaporation time
Abstract
Results of an experimental study of ignition of a water-coal fuel in a high-temperature air flow are presented. The fuel is obtained on the basis of the mark D coal or filtrational cake of the Severnaya dressing plant. Based on the experimental results, physical and mathematical models of the processes of thermal preparation and ignition of water-coal fuel particles are formulated, which take into account the joint proceeding of the most relevant physical and chemical transformations (which exert an essential effect on the ignition condition) and the processes of heat and mass transfer during the induction period. A comparison of the basic ignition characteristics (ignition delay time and limiting values of the gas medium temperature), which are obtained experimentally and theoretically (based on results of numerical simulations), leads to a conclusion that the water film affects the dynamics of the ignition process.
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