L. Y. Zhuo, Y. Jiang, R. Qiu, J. T. An and W. Xu (2014) Effects of Fuel-Side N-2, CO2, H2O Dilution on Combustion Characteristics and NOx Formation of Syngas Turbulent Nonpremixed Jet Flames. Journal/Journal Of Engineering for Gas Turbines And Power-Transactions Of the Asme 136 7. [In English]
Web link: http://dx.doi.org/10.1115/1.4026427
Keywords: syngas turbulent flames, NOx formation, dilution, extinction and, reignition, DIFFUSION FLAMES, EMISSION CHARACTERISTICS, REIGNITION, EXTINCTION, MODEL, H-2
Abstract: The effects of the three fuel-side diluents N-2, CO2, and H2O on the accurate flame structure and NOx formation characteristics of the turbulent syngas nonpremixed flames are investigated using the one-dimensional-turbulence (ODT) model. For nonpremixed flames, the fuel mixtures consist of H-2, CO and three diluents: N-2, H2O, and CO2. The proportion of diluents is varied from 10% to 30% while the H-2/CO ratio is kept as a constant at 0.75 all the time. Mass fraction of main species and temperature of 30% N-2 basic dilution case predicted by the ODT model are compared with the tests measuring results obtained by International Workshop on Measurements and Computation of Turbulent Nonpremixed Flames, and it is found that the results are in good agreement. Numerical results indicate that the CO2 diluted flames have the largest reduction on flame temperature as well as the NOx emission, while H2O is more effective than N-2. For CO2 and H2O dilution flames, flame structure becomes unstable with an obvious lift phenomenon. Since ODT captures the flame extinction process, flames added with CO2 and H2O not only have a lower extinction temperature but also the reignition process is slower.