Experimental Study Of The Burnout Of The Blended Coal And The Optimization Of Coal Distribution

With the sharp increase in the power requirement, the consuming of coal for the coal-fired power plant is increasing considerably. It becomes harder and harder for most power plants to use a certain type of coal for a long time. Under this condition, it necessary for the power plant to use the blended coal without the decreasing of efficiency.The combustion of blended coals is an extraordinary complex physical and chemical process. During this process, the component coals affect each other, so the blended coals exhibit different combustion characters as well as the burnout behaviors from the single coal. Some researchers has hold an opinion that the burnout behavior of blended coal is between behaviors of the raw coals for blending. However, further studies are needed for the effect of components of blends on the burnout characters.Firstly,the various factors affecting the burnout character of coal was analyzed in this paper, It is different from the former studies that the FZ has a linear relationship to the blending ratio. After that, the burnout behavior of blends was studied using Thermogravimetric Analyzer (TGA) and Drop Tube Furnace (DTF). We can find a better burnout character if we add the easily burnt coal to the hardly burnt coal, on the other hand, the burn out character will get worse if we add the hardly burnt coal to the easily burnt coal, and the burn out character will be close to the character of the hardly burnt coal. We also found there is a good relation between the burnout character and the blending ratio during the TGA analysis, while this is not found in the DTF analysis. Since the working conditions of coal in the DTF are more close to the working conditions in the power plant, the linership of the burnout behavior of blends and components could be used approximately when the power plant use these kinds of coals.At last, the influence of the quality of coal on the boiler operation was also analyzed, the optimal blending ratio was figured out by counting up kinds of factors.