Experimental Investigation And Engineering Application Of Blending Lignite With Bitumite In Boiler Of Power Plant

There is abundant lignite resources without thoroughgoing utilization in the coal-fired power plant in China, although the reserve of power coal is limited and its supply is becoming shortage in recent years. Therefore, the research and development on the co-firing lignite with bituminous coal is of great significance for power industry in China.The effect of coal characteristics on boiler operation is analyzed in this thesis. Based on the mixing method, blend ratio and current problems of co-combustion two kinds of coal, thermogravimetric method (TGA) from ambient to900℃with a heating rate of20℃/min under air. Lignite was blended with two type of bituminous coal in proportions of10%,30%and50%, respectively. In order to understand the blending ratio, combustion index is calculated using characteristic temperature method.According to experimental investigation, field tests are conducted by using40%lignite with bituminous coal in Jinglong Coal-fired Power Plant. The results show that Bao type of goal is more available to reduce the feed cost. Furthermore, the operational parameters of the boiler are adjusted to improve the efficiency of coal-fired power plant. After the optimization, the efficiency increases by0.57%, the main steam of desuperheating water flow reduces54.6t/h, the flow of reheat desuperheating water decreases3.9t/h, and the frequency of soot blowing is sharply decreased. As a result, the fuel cost is saved remarkably for Jinglong Coal-fired Power Plant. Moreover, The NOx emission is lessened and slagging phenomenon is also reduced. Overall, the lignite blinding method suggested in this thesis can ensure safe operation of boiler, but also enhance economic performance in the power plant.