Numerical investigation of burning reserve fuel in combustion chamber of boiler BKZ-420-140

Abstract

Relevance of the work is caused by the need to assess the effectiveness and reliability of the boiler units on reserve fuel after reconstruction associated with a change in the base fuel and approaches of numerical analysis. The main aim of the research is to analyze physical and chemical processes in the furnace volume of boiler BKZ-210-140 operating on reserve fuel and rated load when using the Euler and Euler combined and Lagrangian modeling approaches; to construct the mathematical models of the object of study, taking into account the number of rational settlement areas and application of modern numerical algorithms and approaches; to compare numerical results obtained by using different software packages and different representations of the combustion of liquid fuel in the power boiler furnace; to evaluate temperature fields in the volume of the combustion chamber, the concentration of chemical elements of the combustion products, formation of a wind flow patterns and efficiency of backup fuel burn. Methods: numerical simulation based on the Euler and Lagrangian approaches, the finite volume method, wall functions, the two-parameter k-e? turbulence model, the model of the chemical reaction in a turbulent flow Eddy-Break-Up - EBU, P1 approximation of spherical harmonics method, the theoretical calculation based on the standard method of thermal calculation of boilers. Results: numerical representation of physical and chemical processes in the furnace of the boiler BKZ-210-140 at reserve fuel combustion; comparison of the results obtained by different numerical models; assessment of the reliability of evaporator surface functioning and efficient of operation of the reserve fuel boiler unit; recommendations for improving the combustion mode in order to increase the operational efficiency of the boiler BKZ-210-140 when combusting fuel oil