Burning low volatile fuel in tangentially fired furnaces with fuel rich/lean burners

Optimization of air staging in a 1 MW tangentially fired pulverized coal furnace

“…10 shows that NO x reduction efficiency increases with RRL at the beginning, then NO x reduction efficiency reaches a maximum value at RRL = 3, and NO x reduction efficiency declines slightly at the end. In the horizontal bias combustion burner, the pulverized coal combustion with rich/lean streams may have a great influence on NO x reduction [24]. The less air supply inhibits fuel-NO x formation in the rich stream of pulverized coal, and, and thermal-NO x formation is also limited because of the low temperature in the coal lean stream of pulverized coal.…”

Determining the optimum coal concentration in a general tangential-fired furnace with rich-lean burners: From a bench-scale to a pilot-scale study

“…Generally, the overall mass ratio of pulverized coal and air (coal concentration, kg/kg) in the primary air of traditional burners is approximately 0.3e0.6; maintaining a stable flame for low-grade coal is difficult at such a low concentration [6]. However, Fig.…”

A dimensionless factor characterizing the ignition of pulverized coal flow: Analytical model, experimental verification, and application

“…On the other hand, when the proportion of volatile in coal arises, the theoretical optimal concentration of pulverized coal decreases. Previous experimental studies [11,12] have verified empirically that (depending on the specific type of coal and burner) there exists an optimal concentration of pulverized coal during its combustion. However, such empirical result is not as explicit and universal as the one (Equation (18)) proposed in this paper.…”

“…Conventionally, for a given type of coal and a specific burner, extensive experiments need to be carried out to identify an empirical relationship between the ignition characteristics of pulverized coal [11,12]-such an empirical relationship is in general not transferable to other types of coal/ burner without an appropriate modeling effort. By using cold tests and industrial tests, Li et al [3] investigated the radial bias combustion of pulverized coal swirl burners burning low-grade coals and low-volatility coals.…”

“…Zhou and Cen [13] measured the distribution of concentration of pulverized coal in a furnace via a cold test, although no model was established to correlate their results with combustion. Wei et al [12] carried out hot test of low volatile coal combustion in a tangentially fired furnace and measured the carbon content in the charcoal and NO x emission; these two parameters were plotted with the experimental parameters without any theoretical basis. Faundez et al [14] carried out ignition tests of three coals of different ranks, and found that the ignition temperature of a coal blend is always close to the lower rank coal in the blend; the relationship between ignition temperature and the properties of burner and furnace was not discussed.…”