| The coal-fired electricity dominates in the power generation in China. It not only consumes lots of end-energy, but also brings results in serious environment pollution. To save the coal resource and reduce pollutant emission is one of key issues faced by the power plants in China. How to get good air dynamic field and combustion formation to decrease NOx emission are then the primary target of the research. Hence, it is of great importance to study and develop control technologies on high efficiency, low NOx emission and low load stability combustion, in order for the re-adjustment of power generation structure and the steady sustainable development of the power industry.To solve problems such as low thermal efficiency, high NOx emission of a 150t/h pulverized coal boiler, literrature review and analytic demonstration were first carried out on the existing technics of high efficiency and low NOx emission. On the basis of discussion of the formation mechanics of NOx in the combustion process and the control technique of NOx emission of pulverized coal boiler, the technology of local enriched-oxygen supporting combustion (LEOSC) was developed and a system of membrane oxygen-enrichment was designed, which has been applied in the practice for the first time. Models of low NOx combustion and thermal efficiency characteristics were developed in the thesis with artificial neural network, and integral combustion was optimized using heredity algorithm. A software for guidance of boiler operation for high efficiency and low NOx emission combustion was developed to help to achieve the targets under usual operating situations.The practical results proved that the LEOSC technology is good for decreasing of NOx emission with high thermal efficiency through reasonable combustion organization and optimal operation. The reliable, economical and stable operation of the boiler can be guaranteed.
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