【摘要】 某亚临界锅炉超低NO_x排放改造发生高温腐蚀情况,对其水冷壁贴壁气氛进行了测试,并采用模拟装置对腐蚀产物进行理化分析。结果表明:节点功能区、主燃烧区和燃尽区之间的还原区还原性气氛较强,2号角和4号角总体二次风量相对不足,这样增大了2个角附近区域的高温腐蚀;机组高-低负荷循环波动使高温腐蚀不断深入;若管材含有一定的Cr元素,可增强管材的抗腐蚀能力。在锅炉实际运行中,应改善二次风不均匀性,同时在腐蚀风险较高的区域合理应用含Cr元素管材。更多还原

【Abstract】 In order to eliminate the high-temperature corrosion on water wall of a subcritical boiler after ultra low NO_x emission transformation, the atmosphere around the water wall was tested, and simulation device was employed to carry out physical and chemical analysis for the corrosion products. The results show that, the reducing atmosphere was strong at the node function area and the reducing zone between the main combustion zone and the burning-out zone. The overall secondary air volume at No.2 and No.4 corner was relatively insufficient, which increased the high temperature corrosion in the area near the two angles. The high-and low-load cycle fluctuation of the unit caused continuous deepening of high-temperature corrosion. The corrosion resistance of the pipe can be enhanced if the pipe contains a certain Cr element. In actual operation of the boiler,the non-uniformity of secondary air should be improved, and the Cr-containing pipe shall be reasonably applied in the areas with higher corrosion risk.更多还原