燃烧器的结构优化及变负荷下的燃烧特性研究

Taking the burner of a 10 MW coal-fired test bench as the research object, the influence of the structure of the burner, different loads and different variable load rates on the combustion characteristics was studied by simulation method. The results show that increasing the blade with an inclination angle of 30° at an appropriate position in the horizontal bias burner and changing the blade angle can greatly improve the concentration ratio of the burner and reduce the concentration ratio of the burner. The thickness of the bluff body at the outlet of the burner is too thick, which will cause the high temperature zone of the combustion to deviate from the main combustion zone, and too small will lead to poor combustion effect. When the load is higher than 60%, the gas flow in the furnace is rigid, the gas is filled well in the furnace, and the combustion energy is maintained in the area around the horizontal plane of the burner center. When the load is less than 40%, the gas rigidity gradually weakens with the decrease of the load, and the gas dynamic field becomes worse. When the load reaches 20%, the airflow cannot be maintained in the area around the central horizontal plane of the burner, and begins to shift downward to the central horizontal plane of the secondary air. However, when the load is 40%, the high temperature area in the furnace can still be maintained in the area around the central horizontal plane of the combustion zone, and the burner can burn stably at 40% load. When the load is reduced to 20%, the high temperature area in the furnace is greatly reduced, and the area with temperature above 1 470 K only appears in the center of the furnace, and the combustion is unstable. Under different variable load rates, the burner can burn stably, and there will be no significant temperature change, but during the variable load operation, there will still be some time periods when the combustion becomes severe. With the increase of variable load rate, the temperature change rate of furnace outlet increases, and the temperature change rate of furnace outlet decreases under high load change rate.