Investigation Of Pulverized Coal/Blast Furnace Gas Blended Combustion That Affect Pulverized Coal Complete Combustion

With the development of modern civilization, global energy crisis has drawn muchattention of human beings. Human beings were required to explore new energy resourceand pay more attention to the use and recycle of secondary energy for the energy crisis.Blast furnace gas (BFG) is the main secondary energy resource in steel companies. It is notonly helps to ease the electricity tension of steel companies but also lead to obviousdecrease in CO pollution, energy savings, environment improvement and considerableeconomic and social benefits if we take full advantage of BFG. But it is difficult to makeuse of BFG due to the low calorific value of BFG. There are many kind of technique to make use of BFG, BFG fired plant project is themost popular one (include pulverized coal and BFG blended combustion,BFG combustionindependently). And blended combustion is more important than others now. But there is avery important disadvantage t: with the increase of BFG blended rate, the combustible inthe ash raise sharply, and the efficiency of boiler decreased obviously. Aim at this problem, analyzed the factor caused pulverized coal complete combustionafter adding BFG. And gained a conclusion: time that pulverized coal keeps in furnaceshorten and temperature level decline is the important reason above all. Based on calculation of the two factors, combine with experimental investigation onone-dimensional furnace and burette furnace. Analyzed the reason that combustible in theash raise sharply if the adding rate of BFG over 20 percent. And draw a conclusion that themost available BFG adding rate based on pulverized coal complete combustion is 25percent if there is no way to increase the combustion temperature. The result ofexperimental investigation also indicated that anthracite is not fit for blended combustionwith BFG. The quality of BFG provided to boiler by blast furnace is not stabilized generally. Thiscaused efficiency of boiler decline. And then, we put forward the optimize model of BFGadjust over whole steel company. Combined with reconstructive of a certain steel company IIboiler to use BFG blended combustion with pulverized coal, summarized optimizeoperation experience of such kind of boiler. Finally, the dissertation discusses project ofboiler optimize design to settle the problem of pulverized coal complete combustion inblended combustion boiler.