Effects of hydrogen addition to methane on the thermal and ignition delay characteristics of fuel-air, oxygen-enriched and oxy-fuel MILD combustion

The present study investigated the effect of adding hydrogen to methane on the thermal characteristics and ignition delay in methane-air, oxygen-enriched and oxy-fuel MILD combustion. For this purpose, numerical simulation of MILD furnace is performed by k-epsilon turbulence, modified EDC combustion, and DO radiation models. Additionally, a well stirred reactor (WSR) analysis alongside with CFD simulations is used for getting the better insight of combustion process and numerical results. The results show that H-2 addition to CH4 provides a more uniform temperature field with higher peak and average temperatures under a similar oxidizer atmosphere. Also, more ignition delay time (IDT) obtained by the replacement of CO2 with N-2, can be compensated by consideration of H-2 in the fuel composition. This study implies that the use of H-2 as an additive to methane is an effective strategy for conversion of methane-air to oxy-fuel combustion system with almost identical thermal and ignition characteristics. (C) 2021 Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC.

Automated summary

The study demonstrates that adding H2 to CH4 can result in a more uniform temperature field with higher peak and average temperatures, while compensation for additional ignition delay time can be achieved by considering the presence of H2 in the fuel composition.