锅炉水冷壁壁面高温腐蚀及壁管横向裂纹泄漏试验研究

Experimental Study on High Temperature Corrosion of Boiler Water Wall and Transverse Crack Leakage of Wall Tube

考虑到锅炉水冷壁壁面高温腐蚀会导致壁管产生裂纹而出现泄漏事故,为了得到影响锅炉水冷壁壁面高温腐蚀的因素,提出锅炉水冷壁壁面高温腐蚀及壁管横向裂纹泄漏试验研究。针对锅炉水冷壁高温腐蚀区存在的横向裂纹进行失效分析,通过宏观观察,材质分析和无损检测,研究分析锅炉水冷壁管横向裂纹的产生原因,再根据锅炉水冷壁壁面高温腐蚀实验原理,确定气氛条件,通过试样块的制备,设计了锅炉水冷壁壁面高温腐蚀实验方案,测试了气氛条件和温度对锅炉水冷壁壁面高温腐蚀的影响。结果表明,锅炉烟气的H_(2)S含量越多、温度越高,壁温波动导致的热疲劳应力和高温的共同作用下,锅炉水冷壁的壁面腐蚀越严重,从而使壁管产生横向裂纹而发生泄漏。

Considering that high-temperature corrosion of boiler water-cooled wall surfaces can cause cracks in the wall tubes and lead to leakage accidents,in order to obtain the factors affecting high-temperature corrosion of boiler water-cooled wall surfaces,a test study on high-temperature corrosion of boiler water-cooled wall surfaces and transverse crack leakage of wall tubes is proposed.Failure analysis was conducted on transverse cracks in the high-temperature corrosion zone of boiler water-cooled walls.Through macroscopic observation,material analysis,and non-destructive testing,the causes of transverse cracks in boiler water-cooled wall pipes were studied and analyzed.Based on the principle of high-temperature corrosion experiments on boiler water-cooled wall surfaces,the gas conditions were determined.Through the preparation of sample blocks,a high-temperature corrosion experimental plan for boiler water-cooled wall surfaces was designed.The influence of atmosphere conditions and temperature on high-temperature corrosion of boiler water-cooled wall surfaces was tested.The results show that the more H_(2)S content and temperature in boiler flue gas,the more severe the wall corrosion of boiler water-cooled walls under the combined effect of thermal fatigue stress and high temperature caused by wall temperature fluctuations,resulting in transverse cracks in the wall tubes and leakage.