Experimental Study On The Characteristic Of NOx Emission During The Pulverized Coal Ignition

With the development of electric power industry, the coal consumption will continue increasing within a long period of time as well as the NOX emission. However, the large amount of NOX emission will cause serious pollution and damage to the environment. Therefore, it is urgent and critical to control the NOX emission in the field of energy and environment.According to the NOX formation mechanism, NOX control technology has been developed. The low NOX burner is one of the greatest control techniques. In order to bring its effect into full play, the factors that influence the formation of NOX need to be studied comprehensively in practical operation of power plant. Though there are a large number of studies in the characteristics of NOX emission, most of them focus on the theoretical study, the static combustion and the stimulation to the entire furnace. Few experimental studies are performed in the characteristics of NOX emission during the pulverized coal ignition.In this thesis, the characteristics of NOX emission along the self-designed ignition furnace were investigated for three typical pulverized coals under different main air rates during ignition stage. Other factors were analyzed particularly. The results show that NOX are mainly produced in the primary ignition zone. Its concentration reaches the peak which relates to the volatile content. Main air rate has a great influence on the release of NOX. With the decrease of main air rate, NOX decreases gradually. However the lower is not the better, there exists an optimal main air rate. Temperature plays an impact in the NOX formation under the experimental condition. NOX emissions are close related to the coal sort. The NOX concentration increases with the increase of volatile content. Content of ash and moisture also exert some influence. But nitrogen content has a small influence in the NOX formation.