2×660 MW超超临界锅炉再热汽温偏差大的治理和调整

2×660 MW Ultra-Supercritical Boiler Treatment and Adjustment of Reheat Steam Temperature Deviation

广东粤电大埔发电有限公司2×660 MW超超临界П型锅炉,自投产以来总体运行良好,但运行过程中在炉膛出口两侧烟温存在偏差,使再热器左右侧汽温存在较大的偏差,致使再热器一侧减温水用量偏大,导致减温器管道内出现裂纹。通过对炉膛出口存在的残余旋转动量的方向与汽温偏差之间的关系、燃烧器燃尽风偏转角及消旋动量的分析,认为消旋动量不足是引起汽温偏差的主要因素。经过对燃尽风喷嘴水平摆动角度调整,燃尽风偏转角从-15°~+15°改进为-25°~+25°,同时对二次风进行配风调整,最终解决了再热汽温偏差和两侧减温水偏差大的问题。由于炉膛出口两侧烟气温度趋于均匀,使得悬吊管壁温也更均匀。

The 2×660 MW ultra-supercritical two-pass boiler of Guangdong Yuedian Dapu Power Generation Co.,Ltd.,has been running well since it was put into operation.However,there are deviations in the flue gas temperature at both sides of the furnace outlet during operation,which makes the steam temperature at the left and right sides of reheater deviate greatly,resulting in a large amount of desuperheating water used on the reheater side,and cracks in the desuperheater pipeline.Through the analysis of the relationship between the direction of residual rotational momentum and the deviation of steam temperature in the furnace outlet,and the deflection angle and the racemic momentum of the burners over fire air(OFA),it is considered that main the factor causing steam temperature deviation is the lack of racemization momentum.After adjusting the horizontal swing angle of the OFA nozzle,the original OFA deflection angle was improved from plus or minus 15 degrees to plus or minus 25 degrees,and the secondary air distribution was adjusted,which finally solved the problems of reheat steam temperature deviation and excessive desuperhe ating water on both sides.As the flue gas temperature at both sides of the furnace outlet tends to be uniform,the temperature of the hanging tube is also more uniform.