NO_xFormation, Control and Reduction Techniques

Abstract

The formation of nitrogen oxides (NO x ) in combustion systems is an important environmental concern. The control of NO x emissions and modern reduction techniques is based on worldwide investigations performed in this field. In this chapter, developments in the understanding of nitrogen chemistry in flames during the pas twenty years following the seminal studies of Miller and Bowman [1] are summarized. The different routes of NO x formation, including the newly proposed NNH route and prompt‐NO via NCN and other precursors, are discussed. The results of recent laboratory studies on NO x control through reburning are also detailed. Other approaches for NO x control, including low‐NO x burners, flue gas recirculation, and over‐fire air, are also outlined. Of special and practical interest are the selective noncatalytic reduction (SNCR) techniques; these include ammonia‐based, urea‐based, ammonium carbonate‐based SNCRs, and additive‐enhanced SNCR. An example of nitrogen‐containing additives for the simultaneous reduction of NO x and minimization of corrosion is presented. Finally, potential future developments and areas of use of these reduction techniques are discussed.

Influence of turbulence on the efficiency and reliability of combustion chamber of the gas turbine

“…This method of organizing the combustion process in the combustion chambers simultaneously provides a high completeness of fuel combustion, but at the same time greatly reduc-es its reliability and the range of loads of stable operation [11][12][13]. A decrease in the reliability and stability of the combustion chamber is associated with the following: -flame breakthrough, due to which thermal destruction and burnout of the fuel of combustion devices occurs, -poor flame-out, which causes pressure pulsations and mechanical stress on the parts of the combustion chamber and turbine, -the formation of a fuel-rich hearth in the flame, which is the main reason for the existence of local hot zones, -in traditional burners, due to the uneven temperature field, the guide vanes of the first stage of the gas turbine fail, and -when the load is reduced, there is a danger of flame breakdown and flame breakthrough.…”