Development Of Oxygen-enriched Incineration Technology In The Municipal Solid Waste Grate Incinerator Based On CFD And Optimization Design Of Oxygen Injector

Incineration is one of the most effective means of achieving waste harmless, reduction and recycling. With the growing environmental problems, increasingly strict environmental standards will greatly limit the development of waste incineration technology, therefore,developing a new type of clean and efficient waste incineration technology will be the inevitable trend in waste incineration industry. In this study, the development of municipal solid waste(MSW) grate incinerator oxygen-enriched incineration technology and the optimization design of oxygen-enriched incineration injector were studied by Computational Fluid Dynamics( CFD) technique.First of all, three incineration conditions were simulated to predict the important information on the incinerator, i.e. conventional air incineration, oxygen-enriched incineration without flue gas recirculation, and oxygen-enriched incineration with flue gas recirculation. Results show that on the condition of oxygen-enriched incineration with flue gas recirculation, the combustible gas and oxygen mixed fully.Meanwhile,since the temperature distribution was more uniform in the furnace, the combustible gas burned more completely.In addition, the organization of flow field in incinerator was better, hence,the the flue gas residence time in the furnace was improved effectively by flue gas recycling.Secondly, the numerical simulation was applied to the MSW grate incinerator with oxygen-enriched incineration for local optimization. Result shows that in a reasonable scope, increasing the proportion of the gas, adjusting the circulation ratio of gas volume on front and back wall and changing angle of nozzle on front and back wall can get a better flow field distribution and combustion heat transfer effect.Then, the velocity field, temperature field, concentration field and other important information were investigated for different types of oxygen injector with CFD method. The results show that ring-type oxygen injector achieved a very good mixture effect with minimum resistance pressure drop. Compared with the nozzle-type oxygen injector and expansion pressure-type oxygen injector is more in line with the need of the engineering practice.Finally, the influence of adjusting the parameters of the part of the structure on thetemperature distribution, velocity distribution and the concentration of mixed gas was explored to realize the structure optimization of ring-type oxygen injector. The results show that when the oxygen injector ring diameter is 0.7071 D,the air pipeline length is 1.4D, the oxygen injector nozzle outside is 0.28 d, and the inner hole is 0.4d,the optimal oxygen injection effect can be achieved.