Influence of Different Outer Secondary Air Vane Angles on Flow and Combustion Characteristics and NO_xEmissions of a New Swirl Coal Burner

Abstract

Measurements were taken for a 300 MWe wall-fired pulverized-coal utility boiler installed with eight centrally fuel rich swirl coal combustion burners in the bottom row of the furnace during experiments. For various outer secondary air vane angle settings, flow characteristics, gas temperature and gas species concentrations in the burner region were measured. The results show that with decreasing outer secondary air vane angle, the swirl intensity of air, divergence angles and maximum length and diameter of the central recirculation zone all increased; the turbulence intensity of the jet flow first increased and then quickly decreased. With decreasing outer secondary air vane angle, the rate of increase in the gas temperature in the early stage and the rate of decrease in the later stage increased along the jet flow direction. For outer secondary air vane angle of 25°, the O2 concentration along the jet flow direction in the burner region was low, and the CO concentration decreased with increasing outer secondary air vane angle. For outer secondary air vane angles of 30° and 35°, the NO x concentrations were less than those for 25° and 40° outer secondary air vane angles. Gas species concentrations in the side wall region varied slightly with a change in the outer secondary air vane angle.

Effects of Secondary Air on Flow, Combustion, and NOx Emission from a Novel Pulverized Coal Burner for Industrial Boilers

“…The observations in Figure 7 are in good agreement with the experimental results presented in the literature. 9,18 A double-peak pattern is seen on the curves of the radial velocity component in the slices near the exit of the PA and SA nozzles (x/D < 0.250), as shown in Figure 8. The maximum value of the outer peak becomes higher with increasing swirling intensity of the inner SA.…”

Gas/particle flow and combustion characteristics and NOx emissions of a new swirl coal burner

“…The single-phase test facility [39,40] consists of a wind box, valve, dynamic pressure meter, model burner, coordinate frame, and an IFA300 constant temperature anemometer system. The threedimensional flow field, the jet borders and the central recirculation zone boundary of the burner were measured.…”

Combustion Characteristics and NOx Emission through a Swirling Burner with Adjustable Flaring Angle

“…Li et al [16] discussed the effect of swirl burner outer secondary air vane angle variation on combustion characteristics and NO x emissions with laboratory-scale and industrial-scale experiments, respectively. Jing et al [17] also researched the influence of swirl burner outer secondary air vane angles on combustion and NO x formation in 300 MW wall-fired boilers. Luo et al [18] proposed a swirl burner with dual-gear rings and double conical flaring based on dual register structure, and experimentally studied the effect on combustion and NO x emissions in the laboratory.…”