Currently, thermal power plants operating on hydrocarbon fuels (gas, fuel oil, peat, shale, etc.) are one of the main sources of electricity. An effective and promising method for suppressing harmful emissions (NO_x, carbon oxides, soot) from the combustion of fossil fuels is the injection of steam into the combustion chamber. The influence of various mathematical submodels was studied on the accuracy of the numerical simulation of the process of n-heptane combustion in a laboratory burner with steam additive to the reaction zone as a promising chemical engineering method for the disposal of substandard liquid fuels and combustible waste with the production of thermal energy. The problem was solved in a three-dimensional stationary formulation. Systematic verification of these submodels, and a comparison of the results of the calculation with the experimental data obtained were carried out. The comparison with the experimental data was carried out for gas components and temperature distribution at the burner outlet; high agreement of the results was achieved. Optimal submodels of the methodology for calculating the process of fuel combustion in a jet of steam were determined. The best agreement with the experiment data was obtained using the EDC model in combination with a mechanism consisting of 60 components and 305 elementary reactions. More correct simulation results were obtained using the RSM turbulence model and the DO radiation model.

Changing the operating power of a pulverized coal-fired boiler can be an important tool to compensate for fluctuations in wind generation and stabilize power system. Pulverized coal-fired boilers were originally designed for baseload operation but technical modernization and application of new technologies and improved control systems make it possible to use them in balancing power lines with a relatively high contribution of renewable energy sources. A BKZ-540-140-1 boiler serves as an example in a numerical study of the effect of blast oxygen concentration on coal dust combustion processes and ignition stability at low loads. An increase in the blast oxygen concentration stabilizes ignition and increases the efficiency of coal combustion in the boiler. Analysis of the calculated results shows that increasing the oxygen concentration at low-critical loads allows for a localized increase in temperature, which contributes to a reduction in flame size. An increase in the oxygen concentration by 5 and 10% leads to a reduction in the heat loss with flue gas by 13.5 and 20.5%, respectively.