气体再燃低NO_x燃烧器的喷口射流特性  

Flow Characteristics in the Nozzle of a Gas Re-burning and Low-NO_x Burners

作　　者：朱明[1] 张忠孝[1] 周托[1] 

机构地区：[1]上海理工大学动力工程学院,上海200093

出　　处：《燃烧科学与技术》2008年第3期281-287,共7页Journal of Combustion Science and Technology

基　　金：上海市科学技术委员会基金资助项目(061658032)

摘　　要：以宝钢350 MW锅炉为原型建立了冷态模拟实验台,用热球风速仪对气体再燃低NOx燃烧器喷口的流动特性进行了实验研究,并利用射流混合理论解释了再燃气体和炉内旋转气流的混合程度对NOx还原的影响.分析了再燃速度的改变对燃烧器出口区域和实验炉内的空气动力场的流场的影响,并提出了有效混合度的概念.实验结果表明,保持一次风速度为21 m/s不变,再燃气体速度为32 m/s时,再燃气体偏离射流轴线较早,不能射入炉膛旋转气流的中心部位;当再燃气体速度为48 m/s时,导致再燃气体射穿炉内旋转气流;再燃风速度为40 m/s时,射流中心夹角小,有效混合度大,混合强烈,对NOx的还原充分,可认为是最佳工况.Based on the cold mode experimental facility whose orange mode is a 350 MW boiler in Baosteel, the experimental investigations of mixing process of jet flows in the nozzle of a GR-LNB（ gas re-burning and low-NOx burners） were carried out ,the velocities of jet flows were measured by a hot-bulb wind velocity indicator, and the influence of mixability on NOx reduction power was described by the jet mixing theory. The change of flow field with the velocity of reburning gas was analyzed, and the overlay theory of reburning gas on the primary air was proposed. The results showed that various reburning air velocities influenced the aerial dynamic field. The lower the speed of reburning gas（32 m/s） is ,the earlier the reburning gas offsets the axis of jet stream, which can＇ t rip into the center of the rotating gas in the furnace. When the speed of reburning gas reaches 48 m/s, it will shoot through the rotating gas in the furnace. And 40 m/s was proved to be the optimum velocity due to its mixability, among the three working conditions with the minimum jet separation angle and the maximum effective overlay ratio. The results also showed that the structure, position and angle of jet spout and the velocity of reburning gas had an important influence on the overlay of reburing gas on flue gas.

关 键 词：气体再燃 低NOX燃烧器 空气动力场 射流 混合度 

分 类 号：TK16[动力工程及工程热物理—热能工程]