Comparison of combustion characteristics of petroleum coke and coal in one-dimensional furnace

The effect of primary air fraction f₁, outer secondary air swirl strength and excess oxygen coefficient on the combustion characteristics of petroleum coke, Hejin lean coal and Shenmu soft coal are researched on a one-dimensional furnace using a dual channel swirl burner. The results show that with the increase in primary air fraction f₁, the NO_x emission concentrations of both Hejin lean coal and petroleum coke increase, and the combustion worsens in the earlier stage, but the burn-out rate of Shenmu soft coal is improved. The NO_x emission concentration obtains a minimum value with an increase in f₁. The ignition and burn-out rate of petroleum coke and Shenmu soft coal are optimal when Ω_dl is minimum and Ω_dl=0.87, respectively. However, both the NO_x emission concentration of petroleum coke and Shenmu soft coal are minimum when Ω_dl=1.08. The increase in excess oxygen coefficient delays the ignition of petroleum coke, worsens the combustion condition and increases the NO_x emission concentration, but it greatly decreases the NO_x emission concentration of Shenmu soft coal.