Effect of Oxygen-enriched Condition on Ignition Favorable Region in High-temperature Oxygen-enriched Pulverized Coal Ignition

摘要

On the basis of characteristics of high-temperature air oil-free ignition and oxygen-enriched combustion,high-temperature oxygen-enriched ignition was proposed as a new method of pulverized coal ignition for utility boilers,and a device for hightemperature oxygen-enriched ignition was also designed.In order to obtain the law of the effect of oxygen-enriched conditions on pulverized coal ignition in high-temperature oxygen-enriched ignition, the ignition temperatures of design coal for ignition device were obtained in different oxygen concentration conditions by related experiments,and the ignition favorable region was defined.Finally, the effect of oxygen-enriched conditions on the ignition favorable region was obtained by numerical simulation using FLUENT. The results show: temperatures and oxygen concentration of oxygen-enriched gas are two basic factors that affect the size of the ignition favorable region;no larger ignition favorable region appears when the temperature or oxygen concentration is lower;considering the appearance of larger ignition favorable region, the lowest temperature of oxygen-enriched gas decreases with the increase of oxygen concentration;when oxygen concentration is higher than 60%, the temperature of oxygen-enriched gas is the major factor to the size of the ignition favorable region,on the contrary, the oxygen concentration of oxygen-enriched gas becomes the major factor.