Experimental Study On Pilot Test Of Ignition Charactristics Of Bias Coal Jet

Horizontal Bias Combustion Burner is a stable combustion with low NOx emission, without high temperature corrosion and slagging,high efficiency pulverized coal burner. Different jet conditions ignition characteristics of pulverized coal flow for regardless of the pre-combustor design or post-operation are all great importance. To this end, the original 0.5MW swirl burner laboratory test bench was re-design and transformation, to build a 0.5MW single rich lean burner pilot test platform. In close to industrial reality furnace environment for a coal-fired power plant to study the rich lean jet ignition characteristics under different flow conditions, to provide theoretical guidance for the design of the burner.We are ensuring the furnace heat load, air temperature and other operating parameters and conditions remain unchanged, only by changing the burner opening area to change the primary air velocity, study effects of different primary air velocity-on bias coal different ignition characteristics. Research shows that: under different primary air velocities Bias Coal jets began to start fire at a distance of 200 mm vents and flame shape pre-length is longer, as the reaction continues to be, the flame length is gradually shortened. With the increase in the primary air velocity, 200 mm range jet in heating up phase, the temperature is gradually heated and jets temperature increased, but gas components O2 and CO2 concentration trend is gentler. Within the range of 200 mm to 500 mm range, the jet temperature continues to rise, but the rapid decline in the concentration of O2, CO2 rapidly increased, and high air conditions at the center line of the furnace temperature was lowered to low air conditions. Because of high primary air velocity turbulence intensity increased, resulting in volatile combustion dispersion, while strengthening the jet and the surrounding flue gas entrainment, resulting in high air O2 was taken to the surrounding environment caused by lower concentrations. In the regional differences has become less after more than 500 mm range.By analyzing the bias side radial temperature, the nozzle cross section at a distance of 200 mm, the corresponding point temperature of the rich side higher than weak side, and the temperature close to the wall appears ha an increasing trend, and this stage belong to the endothermic phase jet. At two sections distance of 360 mm and 520 mm to burner nozzle opening, in the direction towards the wall without temperature increase trend, indicates for this distance, the jet has been in the heat release stage. By analyzing the radial distribution of flue gas composition, it shows that the jet fire from outside first started and then ignited the fire inside the jet, and finally to the entire jet ignition process.First, ensure the furnace heat load and other operating parameters and conditions remain unchanged, then study the influence of excess air ratio(increased from 0.6 to 1.2) on bias coal different ignition characteristics., the results show that: with excess air ratio increase, less impact on the pre-ignition. But the excess air ratio improve and strengthen the air turbulence inside the furnace, the flue gas mixed coal particles accelerated with the surrounding temperature, improve the heating rate, breaking the post-O2 concentration decreased the reaction inhibition. Excess air coefficient ratio increased make the jet combustion later period of pulverized coal more intensely, and enhance the strength of the fire.