Properties of premixed hydrogen/propane/air flame in ceramic granular beds

This study investigated how various H-2 concentrations of fuel mixed with a ceramic granular bed (CGB) affect the propagation characteristics of a premixed C3H8/air flame. The results showed that at low firing rates (Gamma < 1.5 kJ/s), as Gamma increased, adding H-2 exerted little effect on the flame temperature and absolute flame front velocity (S-ab); however, at high Gamma > 1.5 kJ/s), as T increased, adding H-2 caused a significant decrease in the flame temperature and a substantial increase in S-ab. Thus, heat transfer was not obvious, and the flame reaction zone was relatively broad. Although adding H-2 moved the flame reaction zone upstream, the heat transfer mechanism reduced the effect that resulted from adding H-2 under low Gamma conditions. Because of the characteristics of H-2, the flame reaction zones moved upstream, causing the flame thickness and heat loss to increase. Adding H-2 decreased the flame temperature and increased S-ab. Crown Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.