The Numerical Analysis On NO_x Emissions Of Gas Turbine Combustor

Combustion chamber is one of the key components in gas turbine. It transfers the chemical energy of the fuel into heat energy of the high-temperature gas, preparing for the operation of gas turbine. The main factors of importance in assessing combustion chamber performance are combustion efficiency, pressure loss and outlet temperature and velocity distribution. Numerical simulation is an effective way to study the internal flow, because of the highly complexity of the geometry and the internal flow inside the combustor. Recently, with more and more strict control of the pollutant emission, the causes and effects of industrial pollution become better understood, and NOx emission control has become probably the most important factor in the design of industrial gas turbines. Therefore the study of the combustor NOx emission control technology has a significant impact on the gas turbine performance.The turbulent combustion flow of a gas turbine combustor was analyzed numerically based on the real 3-d model and commercial CFD solver, and the internal flow, combustion efficiency, distribution of temperature and NOx were also studied. In the numerical simulation, the high-Reynolds numberκ-εturbulence model, discrete phase modeling for liquid fuel, rapid chemical reaction system, EBU combustion model and SIMPISO algorithm were applied on the Star-CD software. Steam injection was added to the original model and the new model was simulated numerically for the single-phase flow, spray two-phase flow and the combustion flow simulation, to comparatively investigate the effect of the steam injection on the NOx emission and the combustion performance as well.Compared with the experimental results, numerical results of the combustion without steam injection agree well with the experimental results. NOx emissions were reduced in a large extent due to steam injection, but the combustion efficiency was reduced at the same time. This paper provides a theoretical basis to study the pollution reduction technology in the combustion chamber.