Dynamic Blending Of Theoretical And Applied Research

Coal blending for power can adjust quality parameters of coal, improving combustion efficiency of coal, reducing emission of pollutants ( SO2, NOx, soot ) of coal combustion, decreasing environmental pollution, so it is the widely applied clean coal technology in China at present. In last years, a lot of achievements were made and reported on coal blending for power, but it must be observed that the technology of coal blending is still laggard and many problems on coal blending need be solved. Firstly, this paper discusses the additive of chemical parameters of coal (Heating value, Volatile matter), which is deduced based on the chemical composition or petrographic constituents of coal and China's test standard of chemical parameters of coal, and which conclusions are confirmed by experiment. Secondly, the slow devolatilization of blended coal has been carried out by means of thermal gravimetric analysis and the three—stages kinetic model of devolatilization of blended coal and the factors of effects on devolatilization of blended coal have been gotten on the basis of experimental results. According to the study on devolatilization of blend, it can be interpreted that combustion behavior of two blends with similar quality parameters may be obviously different. Then, the research on combustion properties and behavior of single coal and blended coal has been performed and the method predicting combustion behavior of blended coal has been obtained. The test burning of blend in a small-scale boiler proves that the method predicting combustion behavior of blended coal is correct. The study conclusions provide scientific basis for establishment of mathematical model of coal blending. Finally, the problems on old mathematical model of coal blending is pointed out and the new model of coal blending is established, and software applied to coal blending is developed, which make coal blending scientific and practical. The theory of blend is successfully applied in Zhuzhou coal preparation plant, which prove that the theory is correct.