NUMERICAL SIMULATION OF HEAT AND MASS TRANSFER AT THE PARTIAL STOP OF FUEL SUPPLYING IN THE CHAMBER OF TPP

Аннотация

In this article, using numerical methods, studies have been performed to determine the effect of a forced partial stop of coal dust supply (emergency mode) through burners on the main characteristics of the combustion chamber of the BKZ-75 boiler of the Shakhtinskaya thermal power plant. Using computer simulation methods, various modes of supplying pulverized coal into the combustion chamber were investigated. Direct-flow method of supplying air mixture, when only two direct-flow burners work out of four burners, and two are in emergency mode. The vortex method of supplying the mixture, when two vortex burners operate with four torches with a swirl angle of the mixture flow and tilting them to the center of symmetry of the boiler by 30 degrees, and two are in emergency mode. The performed computational experiments made it possible to obtain the main characteristics of the heat and mass transfer process in the combustion chamber: flow aerodynamics, temperature fields, and concentrations of harmful substances (carbon and nitrogen dioxides) in the combustion chamber and at its exit. A comparative analysis was carried out for the two investigated emergency conditions (direct-flow and vortex), on the basis of which it was concluded that in the event of a forced partial stop of the burners, the use of a vortex method of supplying air mixture improves the metabolic processes in the combustion chamber and reduces emissions of harmful substances into the atmosphere.