Effect of diluent gas on propagation and explosion characteristics of hydrogen-rich syngas laminar premixed flame

Syngas, a promising renewable alternative fuel, shows different combustion characteristics depending on its exact composition. In this study, the effect of different diluents on the laminar premixed flame of hydrogen-rich syngas was experimentally investigated using a 90% H-2/10% CO/air mixture in a constant-volume combustion bomb. In particular, this investigation revealed the effects of varying the equivalence ratio (0.6, 0.8, and 1.0) and dilution content (10%, 20%, and 30%) on the flame propagation and explosion characteristics of syngas/air mixture. The results showed that for a given dilution gas content, the flame propagation speed under CO2 dilution is less than that under N-2 dilution; however, the flame acceleration effect of CO2 dilution is significantly higher than that of N-2. As the dilution increases, the rate of pressure rise and the maximum combustion explosion pressure gradually decrease. For a given equivalence ratio, the maximum rate of pressure rise and the deflagration index of the flame mixed with N-2 were higher than those for CO2. (c) 2022 Elsevier Ltd. All rights reserved.

Automated summary

This study experimentally investigated the combustion characteristics of a hydrogen-rich syngas premixed flame with different diluents. The results showed that the flame propagation speed was lower under CO2 dilution but had a higher flame acceleration effect, and as the dilution increased, the rate of pressure rise and the maximum combustion explosion pressure gradually decreased.