Experimental study on the effect of diluent gas on H2/CO/air mixture turbulent premixed flame

To study the effects of different diluents on the propagation characteristics of H2/CO/air mixture turbulent premixed flames, a series of experiments were carried out in a turbulent premixed flame experimental system. The effects of turbulence intensity (0.49-1.31 m/s), dilution gas content (10%, 20%, and 30%), hydrogen fraction (50%, 70%, and 90%), and equivalence ratio (0.6, 0.8, and 1.0) on the turbulent premixed flame were studied. The results show that with the increase in hydrogen fraction or turbulence intensity or equivalence ratio, the ST and ut increase at the same radius. Compared with N2 dilution, CO2 dilution showed a more obvious inhibition effect on ST. With the increase of Ka, ST;35mm/u' gradually decreased, and the extent of ST;35mm/u' decrease gradually became smaller. As the intensity of turbulence increases or the hydrogen fraction increases, the slope of ST,35mm/u' with Da/Le gradually decreases. In the turbulence intensity range of this experiment, the ut,35mm/ml under nitrogen dilution condition has a larger floating range. The growth rate of ut,35mm/ml at a low equivalence ratio is significantly higher than that at a high equivalence ratio. (c) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

The study examines the effects of different diluents on the propagation characteristics of H2/CO/air mixture turbulent premixed flames. Increasing hydrogen fraction, turbulence intensity, or equivalence ratio leads to higher ST and ut. CO2 dilution shows a stronger inhibitory effect on ST compared to N2 dilution.