This investigation was aimed at studying the influence of 21-30% oxygen concentration on the heating rate, emissions, temperature distributions, and fuel (natural gas) consumption in the heating and furnace-temperature fixing tests. Increase in the oxygen concentration led to a more rapid heating rate and lesser fuel consumption due to lower levels of the inert gas (N 2 ). When the oxygen concentration was increased from 21% to 30%, the heating rate was increased by 53.6% in the heating test and the fuel consumption was reduced by 26.1% in the furnace-temperature fixing test. Higher oxygen concentrations yielded higher flame temperature; hence, the NO x emission increased with increasing oxygen concentration. However, the increase of NO x emission in the furnace-temperature fixing test was less than that in the heating test. Moreover, the NO x emission was more sensitive to the excess oxygen at higher oxygen levels. The CO 2 concentration in the flue gas increased linearly with the oxygen concentration. Additionally, the temperature distributions became progressively nonuniform with increasing oxygen concentration because the convective heat transfer coefficient was altered.
- Oxygen-enriched combustion
- Temperature distribution