不同材质换热管低温腐蚀研究  

Research on low-temperature corrosion of the heat exchanger tubes with different materials

作　　者：刘伟[1] 许利华[1] 俞见阳 LIU Wei XU Lihua YU Jianyang(Hangzhou Boiler Group Co., Ltd., Hangzhou 310021, China)

机构地区：[1]杭州锅炉集团股份有限公司,浙江杭州310021

出　　处：《能源研究与信息》2016年第3期176-180,共5页Energy Research and Information

摘　　要：由于含硫燃料燃烧后易造成锅炉尾部受热面低温酸腐蚀,影响设备使用寿命,因此烟温区域必须选择不同耐腐蚀材料,以确保设备正常运行.依据酸露点温度计算结果及实际工程运行经验,提出了界限温度概念,即在尾部排烟酸露点温度基础上增加5~10℃后的温度.在管外壁温度高于界限温度的烟温区,受热面材料可选择碳钢;在管外壁温度低于界限温度30~40℃的烟温区,受热面材料可选择ND钢或316 L等不锈钢;若管外壁温度进一步降低,则需要选择双相不锈钢、塑钢管等特殊材料.采用试验手段研究了在硫酸质量分数不同时不同材质换热管的耐腐蚀性,试验结果显示：随着硫酸质量分数增大,硫酸腐蚀性增强;而316 L不锈钢在硫酸质量分数不同时都表现出良好的耐腐蚀性.Due to the burning of fuels containing sulfur, low-temperature acid corrosion occurred on the boiler tail heating surface, which affected its service life. Therefore, different corrosion-resistant materials should be selected for different zones where the flue gas temperature was different to ensure its normal operation. Based on the theoretical calculation and practical engineering experience, the critical temperature was proposed, which was 5~10℃ higher than the acid dew point temperature. When the wall temperature outside the tube was higher than the critical temperature, carbon steel could be used in this zone. When it was 30~40℃ lower than the critical temperature,ND or 316L stainless steel was the right choice. Duplex stainless steel or steel pipe coated with plastics was the final choice when it was lower further. The corrosion resistant tests of heat exchanger tube with different materials were conducted with different mass concentrations of sulfuric acid. The experimental results showed that the corrosion of sulfuric acid was enhanced when the concentration of sulfuric acid increased. 316L stainless steel showcd good property of corrosion resistance at different concentrations of sulfuric acid.

关 键 词：低温腐蚀 酸露点 界限温度 耐腐蚀试验 

分 类 号：TM621.2[电气工程—电力系统及自动化]