针对某台超超临界1000 MW机组燃用准东煤锅炉水冷壁出现的沾污结渣、高温腐蚀问题,基于锅炉的燃烧煤种特性、结焦状况以及腐蚀类型,开展了纳米高熵陶瓷涂层在锅炉后墙水冷壁燃尽风区域的工程验证试验.采用宏观检查、扫描电子显微镜(scanning electron microscope,SEM)、X射线衍射(X-ray diffraction,XRD)、拉曼光谱、摩擦系数及表面能测试等方法,分析了纳米高熵陶瓷涂层的使用效果,揭示了纳米高熵陶瓷涂层的防沾污结渣、耐腐蚀机制.试验结果表明,涂层在锅炉运行11个月后完好,表面无明显结焦物、无明显腐蚀凹坑,管壁未发生明显减薄.纳米高熵陶瓷涂层能够较好地解决锅炉水冷壁沾污结渣以及高温腐蚀的问题,为燃用准东煤锅炉的安全运行提供保障.
Abstract
To solve the problems of fouling,slagging,and high-temperature corrosion in an ultra supercritical 1000 MW unit boiler fueled by Zhundong coal,engineering verification test of nano-high-entropy ceramic coating in separated over fire air(SOFA)area of the boiler rear water wall was carried out,based on the coal characteristics,slagging condition and corrosion type of the boiler.Several methods such as macrographic check,scanning electron microscope(SEM),X-ray diffraction(XRD),Raman spectrum,friction coefficient and surface energy test were applied to observe the change of nano-high-entropy ceramic coating before and after experiments,thus to reveal the possible slag resistance and corrosion resistance mechanisms of nano-high-entropy ceramic coating.The results show that,the coating remained intact after 11 months'boiler operation,with no obvious slagging and corrosion pits on the surface and no significantly thinning of the pipe wall.Nano-high-entropy ceramic coating can better solve the problems of fouling,slagging and high-temperature corrosion on the boiler water wall,which provides a guarantee for safe operation of the boiler fueled by Zhundong coal.
关键词
纳米高熵陶瓷涂层/锅炉/水冷壁/防沾污结渣/耐腐蚀
Key words
nano-high-entropy ceramic coating/boiler/water wall/anti-fouling and anti-slagging/corrosion resistance
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