Application of overfire air technology on an example of a steam boiler PK-39 of the Aksu TPP (Kazakhstan)

Year 2018, Volume: 6 Issue: 4, 217 - 223, 28.10.2018

A. Askarova S. Bolegenova

https://doi.org/10.17694/bajece.475543

Abstract

When burning any fossil fuels, one of the
most harmful combustion products are nitrogen oxides NOx, which damage both the
environment and human health in particular. Reduction of NOx emissions from
fuel combustion at TPPs plays an important role in reducing the total level of
nitrogen oxides NOx emitted into the atmosphere. One way to reduce the concentration
of nitrogen oxides NOx is the stepwise combustion of the pulverized coal
mixture, in particular the «Overfire Air» technology. The essence of this
method is that the main volume of air is fed into the pulverized burners, and
the rest of the air is further along the height of the torch through special
nozzles. Structurally, the method of stepwise combustion of fuel can be carried
out in boilers with a two-tier arrangement of burners along the height of the
combustion chamber. In this case, practically no significant reconstruction of
the boiler is required, which is associated with additional costs. In the
present work, computational experiments on the use of modern overfire air
technology (OFA) in the combustion chamber of the PK-39 boiler of the Aksu TPP
were carried out and the fields of the main characteristics of heat and mass
transfer, as well as the influence of the mass flow of the oxidant through the
OFA injectors on the combustion process were obtained.

Keywords

coal combustion, numerical simulation, overfire air technology

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