1000 MW超超临界锅炉水动力特性分析及应对措施

Analysis of Hydrodynamic Characteristics and Countermeasures for 1000 MW Ultra-supercritical Boiler

锅炉受热面水动力特性不良易引起水冷壁金属壁温偏差过大,长期的壁温波动使得水冷壁薄弱部位易发生裂纹,导致水冷壁泄漏,严重危害锅炉的安全有效运行。以某1000 MW超超临界直流锅炉研究为对象,针对垂直管圈水冷壁的横向裂纹问题,重点分析了水动力特性对下炉膛水冷壁在不同工况下的运行特性及壁温差对金属壁温的影响,确定了温度梯度最大位置,为锅炉节流孔圈调整提供依据。通过对节流孔圈改造,避免了由于过大壁温差造成的水冷壁横向裂纹产生,为同类型锅炉节流圈的改造提供经验依据,对提高炉膛水冷壁运行的安全性具有重要意义。

Poor hydrodynamic characteristics of the boiler’s heated surface can easily lead to excessive metal wall temperature deviation of water-cooled wall,and long-term wall temperature fluctuations can easily cause cracks in the weak areas of water-cooled wall,resulting in leakage on the water-cooled wall,which seriously affects the safe and effective operation of the boiler.Taking a 1000 MW ultra-supercritical once-through boiler as the research target,aiming at the transverse cracking problem of vertical tube coil water wall,this paper focuses on analyzing the hydrodynamic characteristics of the lower furnace water-cooled wall under different operating conditions and the impact of wall temperature difference on the metal wall temperature.The location of the maximum temperature gradient is determined,providing a basis for adjusting the throttle ring of the boiler.The transverse cracks on the water-cooled wall caused by the temperature difference can be avoided through the transformation of the throttle ring,which provides an empirical basis for the transformation of the throttle ring of the same type of boiler and is of great significance for improving the safety of the water-cooled wall operation of the furnace.