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


  • S.G. Kobzar Institute of Engineering Thermophysics of the National Academy of Science of Ukraine
  • G.V. Kovalenko Institute of Engineering Thermophysics of the National Academy of Science of Ukraine
  • A.A. Khalatov Institute of Engineering Thermophysics of the National Academy of Science of Ukraine
Keywords: pulverized coal boiler ТПП – 312, formation of nitrogen oxides, curling of primary air flow.

Abstract

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.

References

1. Kobzar S.G., Khalatov A.A. [Determination of the effectiveness of reducing emissions of nitrogen oxides by the system of stepwise burning of coal of the boiler TPP 312 of unit №. 6 DTEK Ladyzhyn TPP] [Bulletin of NTUU KPI. Series: Energy and heat engineering processes and equipment]. 2014. № 13 (1056). P. 85–91. ( in Ukr. )
2. Kobzar S.G., Khalatov A.A. [Testing a simplified model for calculating the combustion and the formation of nitrogen oxides during the combustion of liquid fuel], Promyshlennaya teplotekhnika [Industrial Heat Engineering]. V.28, №3. 2006. P.62–66. ( in Rus.)
3. Kobzar S.G., Khalatov A.A. . [Extension of the life of the boiler furnace screens TPP-312 by reducing high-temperature gas corrosion by controlling the flow structure in the furnace volume during coal combustion], [in the book «Problems of resource and safety of operation of structures, structures and machines: Collection of scientific articles»], Kiev: Electric Welding Institute E.O. Paton NAS of Ukraine. 2015. 816 p. Electronic edition. http://www.patonpublishinghouse.com/rus/compilations#winresurs2015/. P. 368–374. (in Ukr.)
4. Kobzar S.G., Kovalenko A.V., Khalatov A.A. [Computer simulation of the erosion of convective heating surfaces of the boiler TPP 312], Promyshlennaya teplotekhnika [Industrial Heat Engineering], 2017. V. 39. №. 5. P. 78–83. ( in Ukr.)

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Published
2019-10-24
How to Cite
Kobzar, S., Kovalenko, G., & Khalatov, A. (2019). SLOW-UP GENERATION OF NITROGEN OXIDES BY TURNING THE PRIMARY AIR FLOW IN THE SWIRL BURNER OF THE BOILER TPP 312. Thermophysics and Thermal Power Engineering, 41(4), 51-56. https://doi.org/https://doi.org/10.31472/ttpe.4.2019.7
Section
Fuel Utilization and Burning, Heat Power Units, Ecology