亚临界锅炉水冷壁低负荷换热特性研究

Study on low load heat transfer characteristics of water-wall of subcritical boiler

针对亚临界锅炉在运行过程中水冷壁处出现的局部管屏变形、拉裂问题,本文以实际运行数据为基础采用数值模拟方法分析了数个低负荷及超低负荷运行工况,结果显示:锅炉低负荷运行时,燃烧稳定性差,火焰易产生偏斜,从而导致高温烟气流场混乱,水冷壁烟气温度、热负荷的不均匀性加剧,极易引起热应力偏差大,造成局部管屏拉裂,甚至爆管。

In view of the local tube panel deformation and crack at the water-wall of the subcritical boiler during operation,this paper analyzes several low-load and ultra-low-load operation conditions using numerical simulation method based on the actual operation data.The results show that:when the boiler operates at low load,the combustion stability is poor,and the flame is prone to deflect,resulting in chaos of the high-temperature flue gas flow field,and the non-uniformity of the flue gas temperature and heat load of the water-wall is intensified.It is very easy to cause large thermal stress deviation,causing local panel crack,and even pipe explosion.