Effects of Operating Conditions on NOx Emission in OFA-type Boiler

OFA형 보일러의 운전조건이 NOx 발생에 미치는 영향

  • 박경우 (호서대학교 기계공학부)
  • Published : 2013.06.10

Abstract

In the present study, the characteristics of combustion phenomena and NOx emission in the OFA-type tangentially injected coal-fired boiler have been investigated numerically in order to find the effect of geometrical variation on the performance of the boiler. For these, numerical analyses of turbulent flow, chemical reaction, and radiation heat transfer are performed by using the computational fluid dynamics method. The predicted results clearly show that NOx formation highly depends on the combustion processes, the temperature and species concentrations. In addition, the optimum conditions for both the maximum NOx reduction and highest boiler efficiency can be obtained by considering the amount of supplied air and the injection angle at OFA, and modifying the boiler configuration. It is also found that the variation of supplied air at OFA is more effective than that of the injection angle for reducing the NOx emission, within the present operating conditions.

Keywords

Computational fluid dynamics;combustion;NOx;overfire air;radiation;tangentially injected coal-fired boiler;turbulent flow

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