۳-D Modeling of Heat and Mass Transfer during Combustion of Solid Fuel in Bkz-۴۲۰-۱۴۰-۷C Combustion Chamber of Kazkhstan

In this paper the results obtained by the numerical method of modeling of Ekibastuz coal burning in BKZ-۴۲۰ combustion chamber of Kazakhstan Power Plant are presented. They are devoted to the numerical simulation of combustion processes in the furnace boiler BKZ-۴۲۰. Boiler’s steam generates capacity equal ۴۲۰ T/h. Boiler has six vertical pulverized coal burners arranged in two levels with three burners on the front wall of the boiler. High ash, low-grade coal from Ekibastuz burned in the furnace. Its ash content is ۴۰%, volatile – ۲۴%, humidity–۵%, highest calorific value is ۱۶۷۵۰ kJ/kg. Milling dispersity of coal was equal to R۹۰ = ۱۵%.It was shown in this research that the most intense burning is observed in the central part of the chamber where the flow temperature reaches about ۹۸۰ °C and it is seen that the temperature reaches a peak in the cross sections of the burners location. The combustion reaction there occurs more intensively.

Keywords:

BKZ , ۴۲۰ , Pulverized coal , combustion , Two–phase flow , Ekibastuz coal , Heat and mass transfer , Modeling , Turbulence