Experiment Study And Numerical Simulation Of Combustion Of Coal Water Slurry With Air Staging

The air pollution has been a world wide problem for everyone. NOx is paid more and more attention as one major part of industrial air pollution. NOx emission from ssil fuel is one of source of the overall NOx emission. The NOx emission during the combustion of Coal-Water-Slurry(CWS) is also becoming a part concerned about.The NOx producing and reducing law during CWS combustion is studied in the thesis. With the experiement researching results in a laboratory reactor and the the numerical simulation results, the influences of the NOx producing and reducing is demonstrated. The NOx producing and reducing during different period of the combustion under different pattern of air-stage combustion are also researched. With the excess air coefficient of1.15and18%of the overall air for the over-fire-air(OFA), the NOx emission of CWS is reduced to212mg/m3. The O2concentration in the initial stage of CWS combustion plays a important role in the producing of the NOx. The NOx emission in the initial stage of CWS combustion consists the majority of the overall NOx emission.A CWS burner is designed for a new built670t/h CWS boiler according to the principles obtained from the basic research results above. The influence factors of less-oil ignition and the compressed air atomization technologies for CWS are studied on the boiler. The experinments of influence of the excess air coefficient and OFA gatage on the NOx emission are conducted during the hot combustion tests.The combustion and air-staged conditions in the670t/h CWS boiler were simulated. The numerical simulation results are consistent wich the experienment results. According the the numerical simulation results under the designed condition and experienment condition, the suggestion of improving of the combustion and NOx reducing are provided. The principles for designing CWS air-staged combustion burner and basic research datas are obtained for the further research in CWS air-staged combustion.