Numerical Simulation And Experiments On Oxygen-enriched And Low NO_x Pulverized Coal Burner For Cement Kiln

Pulverized coal burner is an important equipment of cement clinker calcination in rotary cement kiln. The performance and operation of the burner can influence the quality of cement clinker as well as production. Oxygen-enriched combustion technology is an effective measure for energy saving and consumption reduction. The use of oxygen-enriched combustion technology can not only raise the calcining temperature, the production and quality of clinker, but also save fuel, reduce emission of harmful gas(mainly the NOx) and reduce air pollution. Though there are a few studies about the use of oxygen-enriched combustion technology, the study of oxygen-enriched combustion technology combined with pulverized coal burner for rotary cement kiln has never reported yet.The design of oxygen-enriched and low NOx burner, which uses the oxygen-enriched as primary air, is based on the inductive summary innovation of the status at home and abroad. And the numerical simulation study of the designed burner by means of Fluent includes velocity field, temperature field and the distribution of NOx. The results more accurate reflect the inner flow fields. Meanwhile, the changes of oxygen concentration in the primary air are the key study. A conclusion that when the oxygen concentration at 27 percent gains a lot. Subsequently, this thesis studies the rotary inner flow field by the changes of series operating conditions.In order to validate the reliability of simulation results, a reform and membrane oxygen equipment erection are taken at a cement production line of 1000T/D. The contrast before and after the thermal instrumentation of the application of burner, meanwhile, the technical of oxygen-enriched combustion show that the temperature of flame raises 120 centigrade at least, and production increases by 15 percent, and burning heat consumption decreases by 9.53 percent, finally NOx emission reduction is realized with oxygen concentration at 26.8%.The research works and innovations of oxygen-enriched and low NOx burner can provide guidance for using oxygen-enriched combustion technology to achieve energy saving and emission reduction of NOx in cement industry. Also this thesis can promote the whole cement industry technical progress for reference.