Experimental Investigation of the Scaling-Off Location and the Slag Mass in Pulverized Coal-Fired Boiler with Water-Cooled Slag Removal

摘要

It is of great importance to acquire precisely the scaling-off location and the extent of slagging in the furnace to conduct combustion adjustment and avoid the dropping of bulk slag, An experimental platform where slag cooling is simulated was built, and the features of heat and mass transfer during the cooling process-of the slag were studied. The experimental results show that during the cooling process of the high-temperature slag, the closer the measuring point is to the drop point of the slag, the faster its temperature rises, by a large margin. Meanwhile, the average temperature of the-water in the upper layer shot up first and then decreased, while the temperature of the relatively deep water (>= 3 cm) tended to rise gradually. In addition, the temperature rise of the cooling water and the bursting water evaporation are in direct proportion to the mass of the slag and are in linear relation to the temperature of the slag About 20% of the slag heat is taken by bursting evaporation, and 80% is conducted to the cooling water. In a thermal powerplant's 440 t/h pulverized coal-fired boiler with, water-cooled slag removal, a temperature matrix with eight measuring points was arranged in the slag extractor. The location and mass of the slag in the furnace were determined, and the reason for slagging in,the furnace was analyzed, in order to make fine adjustments to the parameter of air supply, to improve the tangential circle deflection in the furnace further, and to avoid the dropping of bulk slag quenching the fire, which guarantees that the boiler can run safely and stably.