Mathematical modeling of combustion processes of coal-water fuel in low-power marine boilers

At present, coal still has an important role in the global economy. According to the current consumption rate and estimates of coal reserves in the world, its reserves will be used up in 200 — 250 years. Its share in the world consumption of fuel and energy resources is currently about 30 %, and up to 40 % of the world's electricity is produced by coal power plants. However, there is a number of environmental, economic and technological problems associated with the use of coal in the energy sector. Their solution is the improvement of the technology of coal mining and enrichment, as well as the development of new environmentally friendly fuels based on it. One of such fuel type is a coal-water one. The article presents the results of numerical simulation of the combustion of coal-water fuel in a ship's low-capacity hot water boiler. The model has been created in the ANSYS Fluent software package, based on the developed mathematical model of the processes of hydrodynamics, heat and mass transfer, as well as the kinetics of thermochemical fuel transformations during the combustion of coal-water fuel. Various options for the operation of the boiler have been analyzed, which make it possible to provide modes of both solid and liquid ash removal to ensure low harmful emissions into the environment.

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