Study on comprehensive evaluation of slagging characteristics of high-alkali coal blending combustion from Hami Area

In order to solve the problem of serious slagging about Hami high-alkali coal blending combustion,taking two kinds of Shenhua No.2 Mine (high-alkali coal) from Dananhu Area and Balikun Baoli (low-alkali coal) from Balikun Area in Xinjing Hami as study objects,the effect of coal blending ratio and steam dust blowing on flue temperature at furnace outlet and temperature rise rate was investigated by using two-color pyrometry temperature detection system. In addition, the time interval of furnace soot-blowing was calculated based on flue temperature at furnace outlet.The results show that the blending ratio of Shenhua No.2 Mine coal was 81.1% when boiler running in full load condition, flue temperature rise rate at furnace outlet was 17.4 ℃/h, the decrease of furnace outlet temperature after furnace soot-blowing was 68 ℃, and the time interval of furnace soot-blowing was 6.7 h. The blending ratio of Shenhua No.2 Mine coal should be less than 80% in case of the more serious of slagging in furnace. The strategy of this field test was increasing proportion of Shenhua No.2 Mine coal. The blending proportion of Shenhua No.2 Mine coal was gradually increased from two mills among six mills to five mills. The best solution was that the boiler should put five mills inferior into operation, of which, mill A taking in Baoli coal, other mills taking in Shenhua No.2 Mine coal.