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SLOW-UP GENERATION OF NITROGEN OXIDES BY TURNING THE PRIMARY AIR FLOW IN THE SWIRL BURNER OF THE BOILER TPP 312

The aim of the work is computer simulation of the formation of nitrogen oxides in the furnace of the boiler TPP 312 with the swirl of the primary air in the boiler burners. The organization of the vortex flow allows reducing the generation of nitrogen oxides due to the formation of a return flow, which ballasts the combustion zone by oxidation products. The limitation of this technique is the reduction of the combustion temperature which can lead to underburning. 
The objective of the study is to determine the formation of nitrogen oxides based on computer simulation of the gas dynamics of the firing space of the boiler TPP 312 DTEK Ladyzhyn TES when swirling streams of air are used in the burner channels. 
Efficient combustion of fuel, in particular solid, is ensured by three factors: mixing of the fuel and the oxidizing agent, residence time in the temperature zone necessary for the combustion of fuel particles and temperature. The selection of the parameter is under pressure from requirements operating in opposite directions. On the one hand, a higher temperature contributes to better fuel burning, but, on the other hand, the formation of nitrogen oxides increases at a higher temperature. 
Analysis of the data on the quality of coal that comes to the station made it possible to derive the averaged characteristics of coal that were used to improve the combustion model of the software package. 
Conclusions 
In the presence of swirling flow, the maximum temperature is 108 K lower than in the case of a direct-flow burner, which causes a 5% reduction in the generation of nitrogen oxides. Centrifugal flows created a rarefaction zone at the burner axis and the reaction products begin to heat the fuel mixture in the burner itself. The surface area of ​​the beginning of combustion during the application of twisting reduces by 30%. 
The results of the study showed that the twisting of the primary air does not lead to a significant reduction of nitrogen oxides.