整层低NO_(x)旋流燃烧器燃烧特性数值模拟研究与应用

Numerical Simulation Study and Application of Combustion Characteristics of Whole Layer Low NO_(x)Swirl Burner

为研究广东某660 MW燃煤电厂OPCC型旋流燃烧器喷口大面积烧毁的原因,基于数值模拟方法对整层OPCC型旋流燃烧器开展数值模拟研究,采用控制变量法分析中心风、一次风、内二次风、外二次风风速与燃烧特性之间的关系。研究结果表明:两侧的旋流燃烧器采用高于中间处旋流燃烧器的中心风风速时,会造成高温燃烧区不连续且面积较小,中间旋流燃烧器着火及燃烧提前;两侧的旋流燃烧器采用高于中间处旋流燃烧器的一次风风速时,各回流区较为分散且形成的大回流区较差,中间旋流燃烧器喷口处温度增加300℃;两侧的旋流燃烧器采用高于中间处旋流燃烧器的内二次风风速时,高温燃烧区被分割为左、右两部分且中间部分温度仅为777℃,两侧旋流燃烧器喷口处O_(2)体积分数大幅降低;两侧的旋流燃烧器采用高于中间处旋流燃烧器的外二次风风速时,高温燃烧区不连续且整体向炉膛中心线处移动,两侧旋流燃烧器喷口温度上升250~300℃;两侧的旋流燃烧器采用高于中间处旋流燃烧器的风速时,均会增大旋流燃烧器喷口烧损的概率。

To explore the causes of large-area burning of burner nozzle in a 660 MW coal-fired power plant in Guangdong using OPCC swirl burner,this paper carries out the numerical simulation of the whole layer OPCC swirl burner using the numerical simulation method.It adopts the control variable method to analyze the relationships between the wind speed of variable center air,the primary air,the internal secondary air and the external secondary air and combustion characteristics.The research results show that when the swirl burners on both sides adopt the central wind speed higher than that at the middle swirl burner,the high-temperature combustion area will be discontinuous and small,and the middle swirl burner will catch fire and burn in advance.When the primary air velocity of the swirl burners on both sides is higher than that at the middle swirl burner,each reflux area is relatively dispersed and the large reflux area is poor,and the temperature at the nozzle of the middle swirl burner increases by 300℃.When the swirl burners on both sides adopt the internal secondary air velocity higher than that at the middle swirl burner,the high-temperature combustion zone is divided into left and right parts,and the temperature of the middle part is only 777℃,and the O_(2) volume fraction at the nozzle of the swirl burners on both sides greatly reduce.When the cyclone burners on both sides adopt the external secondary air speed higher than that at the middle cyclone burner,the high-temperature combustion zone is discontinuous and moves to the furnace centerline as a whole,and the temperature at the nozzle of the cyclone burners on both sides increases by 250~300℃.When the wind speed of the swirling burner on both sides is higher than that of the swirling burner in the middle,the probability of burning loss of the nozzle of the swirling burner is increased.