Effects of CO(2) and N(2) Dilution on the Combustion Characteristics of H(2)/CO Mixture in a Turbulent, Partially Premixed Burner

[Image: see text] Herein, the influences of CO(2) dilution, N(2) dilution, and CO(2)/N(2) (in which half of the N(2) is replaced by CO(2)) dilution on the combustion characteristics of a turbulent, partially premixed CO/H(2)–air flame were experimentally investigated in terms of the flame structure, flame temperature, and CO and CO(2) concentrations in flames. TDLAS (tunable diode laser absorption spectroscopy) technique and an infrared gas analyzer were used for such purposes. CO(2) dilution not only increases more momentum but also reduces the reaction rate. This results in a much longer flame length than that under N(2) dilution. Compared with N(2) dilution, the L(H) (axial length of the high-temperature reaction zone) values for the same levels of CO(2) dilution and CO(2)/N(2) dilution are much longer. The highest CO concentration in the CO(2) diluted flame is higher than that in the CO/H(2) flame and that in the CO(2)/N(2) diluted flame is higher than in that the N(2) diluted flame. The sizes of the main chemical reaction zone in CO(2) and CO(2)/N(2) diluted flames are larger than that in the N(2) diluted flame. The inflection points in the rates of variation of the flame temperature and the CO and CO(2) concentrations verify that CO(2) dilution creates lower intensities and lower rates of chemical reactions, compared with N(2) dilution.