An Experimental Study On The Burnout Characteristic Of Coal Affected By Ratio And Particle Size

How to ensure a higher boiler thermal efficiency in a coal-fired power plant have been issues of common concern. In the power plant operation, there are two main factors impact the boiler thermal efficiency. The one is as the form of smoke heat loss, the other one is as the form of mechanical loss of incomplete combustion. However, to reduce the smoke heat loss is confined by the small temperature difference in the tail heating surface and the flue gas dew-point temperature. In this case, how to reduce the mechanical loss of incomplete combustion is the main way to improve the boiler thermal efficiency. In the power plant operation, the way to improve the thermal efficiency is to improve the burnout characteristics of pulverized coal. It is bound up with the safety,economic & environment protected run of a utility boiler .In this paper, the laboratory samples are from a power plant in Guangdong province, they are Coal 1, Coal 2, Coal 3, Coal 4. The samples of the study consisted of 16 different ratio blended coals and different particle size coals.First of all, we took the conventional analysis with the samples, such as proximate analysis, ultimate analysis, heating value analysis and so on. Furthermore, we took the thermo-gravimetric analysis. From this analysis, we can get some index of burnout characteristic and activation energy for these samples. Then we do some experiment in the drop tube furnace which is a model of a utility boiler in the SKLCC. Meanwhile, we establish a simplified mathematical modeling of empirical formula to get the burnout time of pure carbon.The conclusion of this thesis is that the coal 1 and coal 3 in the ratio of 3:2 is the best, the coal 2 and coal 4 in the ratio of 1:4 is the worst and the coal 2 is not so sensitive to the particle size than others.