摘要
针对700 MW锅炉低氮运行主、再热蒸汽温度偏低、再热器壁面易超温以及高负荷下升负荷过程中再热蒸汽温度波动大的问题,分析了其原因,并提出了降低运行氧量,减小AA风摆角偏差,和燃烧器上摆角度基准值,调整升、降负荷APC过程的热工系数的优化控制方法。优化后,锅炉高负荷下主蒸汽温度达到设计值,两侧偏差基本消除,再热器壁面13点超温次数减少;中低负荷下,再热蒸汽温度明显升高,偏差减小;高负荷下升降负荷过程中,再热蒸汽温度波动减小。同时,由于降低了氧量,排烟损失减小,锅炉效率有所提高,NOx排放量也降低。这些有效地提高了锅炉机组的安全、经济和环保性能。
The reason of operating problem of a 700 MW tangentially fired boiler including the insufficient temperature of steam, the over-temperature of heat exchanger metal and the abnormal fluctuation of reheated steam temperature during the running down of load with previous high load, under the low-NOx combustion operation was analyzed and measures to resolve these problems were proposed. The measures include lowering the oxygen content of flue gas, reducing the swinging angel bias of A.A nozzles and the reference value of swinging angle of main burners, optimizing the thermal coefficients of APC dynamic processes. After the optimization, the steam temperature with high load reaches the design value and its deviation of two sides is almost reduced, the frequency of over-temperature in 13 points on the reheater is decreased and the fluctuation of reheated steam temperature with the rising and falling of load under the previous high load circumstance is diminished. In addition, the efficiency of boiler is improved and the exhaust gas heat loss is reduced because of the falling of oxygen content in flue gas, while the NOx emission is also lower. All these optimal measures improved the security, economic and environmental performance of this boiler.
出处
《电站系统工程》
2015年第2期50-52,共3页
Power System Engineering
关键词
低氮燃烧
汽温特性
烟温偏差
优化控制
low-NOx combustion
steam temperature characteristics
gas temperature deviation
optimal control
