Characteristic Study Of Air Duct Under CFBB With Plasma Ignition Technology

The circulating fluidized bed boiler is a new generation equipment of high efficiency and low pollution, which has the advantages like fuel wide adaptability of combustion; environmental protection etc. Plasma ignition technology reduced the oil mass in the course of ignition and low load combustion stabilization. It has realized the non-oil startup. It is an efficient means that can decrease cost of power plant. The thesis studies the plasma ignition technology in CFBB in the round firstly.First, the thesis presents the experimental study and the numerical simulation to III plasma ignition burner. The thesis gains the effect of burner structure, primary air velocity and pulverized coal concentration on the ignition characteristics of plasma. The results indicate that the spout diameter of the plasma ignition burner in^350mm is better than that inφ325mm. When the air velocity is 22m/s, and the pulverized coal concentration is 0.3kg/kg, it can ensure high temperature at the exit of the burner and can also guarantee that there is enough pulverized coal burning in the air duct to heat the secondly wind.Secondly, the thesis presents the experimental study and the numerical simulation to the combustion of air duct under CFBB. It studies the combustion of air duct. It also gains the effect of the model change of air duct and air distribution on combustion. The results indicate, air distribution could ensure pulverized coal complete combustion. The board with holes of air duct could decrease circumfluence in air duct, that it avoids air duct burnt. When primary air velocity is 22m/s, compass air velocity is 8m/s, secondary air velocity is 11m/s and pulverized coal concentration is 0.3kg/kg, it can ensure the temperature of heated bed and decrease circumfluence to avaid air duct burnt.At last, the thesis presents theoretical analysis to the problems during the start-up process of CFBB with plasma ignition technology, such as air-hood block, room under CFBB explosion prevention and so on. The analysis shows that pulverized coal won't cause air-hood block. Because of the quantity of the combustible in a low lever, installing ash hopper in the wind chamber and at the end of the air duct, putting ash hopper timing, and reducing the quantity of the formation won't cause deflagration phenomenon happens indoor.Above characteristic studies prove that the start-up process of CFBB with plasma ignition technology is practicable. The technology realizes the non-oil startup. It decreases the cost of power plant.