燃烧器摆角同步性对切圆锅炉再热汽温和壁温偏差的影响研究

Study on the influence of burner swing angle synchronicity on the wall temperature deviation of reheat steam in tangentially fired boiler

为解决某电厂660 MW超超临界机组切圆锅炉日常运行中再热汽温和壁温偏差大、管壁易超温和再热汽温不足等问题,本文研究了燃烧器摆角同步性对汽温和壁温偏差的影响特性。热态运行时,只有将炉外四个角的燃烧器摆角设置在不同位置时,才能在保证管壁不超温的前提下将再热汽温提升至设计值,初步判断造成这一现象的根本原因是炉内四个角燃烧器摆角不同步造成。机组冷态停炉检查时发现,有近一半的燃烧器摆角炉内外定位不一致导致四角不同步,对炉内外燃烧器摆角进行了重新定位。消缺处理后,再将炉外四个角的燃烧器摆角设置在同一位置,再热器两侧的汽温和壁温偏差均有所降低,机组状态显著改善。额定负荷下,在最高点再热器管壁温度降低了8.1℃的前提下,两侧再热汽温偏差降低至1.0℃的同时,再热汽温提升至619.8℃。

In order to solve the problems of large deviation of reheat steam temperature and wall temperature,easy overtemperature of pipe wall and insufficient reheat steam temperature in the daily operation of tangentially fired boiler of 660 MW ultra supercritical unit in a power plant,this paper studies the influence characteristics of burner swing angle synchronization on steam temperature and wall temperature deviation.During the hot state operation,only when the burner swing angles of the four corners outside the furnace are set at different positions,the reheated steam temperature can be raised to the design value under the premise of ensuring that the pipe wall does not exceed the temperature.It is preliminarily judged that the root cause of this phenomenon is the unsynchronized swing angle of the burners in the four corners of the furnace.During the cold shutdown inspection of the unit,it was found that nearly half of the Burners′ swing angle was inconsistent with the internal and external positioning of the furnace,resulting in the four corners being out of sync.After the defect elimination treatment,the burner swing angles of the four corners outside the furnace are set at the same position,the steam temperature and wall temperature deviation on both sides of the reheater are reduced,and the unit state is significantly improved.Under the rated load,the reheat steam temperature deviation on both sides is reduced to 1.0 ℃ and the reheated steam temperature is increased to 619.8 ℃ on the premise that the pipe wall temperature at the highest point of reheater is reduced by 8.1 ℃.