摘要
水冷壁防腐涂层的过早剥落严重影响锅炉的安全运行。针对该问题,建立了涂层—膜式水冷壁热固耦合有限元计算模型,得到了水冷壁的温度场和应力场,分析了导致水冷壁涂层剥落的主要原因。研究表明:温度梯度由涂层向管内壁递减,受水冷壁结构形式、热膨胀系数差异的影响,温度载荷下,涂层与基体接触位置产生较大的热应力,该热应力是导致涂层剥落的主要原因;涂层越厚,接触界面热应力越大,而界面处温度越小;当涂层热膨胀系数小于基体时,涂层膨胀系数越小,界面处热应力越大;当涂层热膨胀系数大于基体时,随涂层热膨胀系数的增加,界面热应力先增大而后减小。
Premature spalling of antieorrosive coating on water wall seriously affects the safe operation of boiler. In view of the problem, a two dimensional thermal mechanical finite element model for coating and film water cooling wall was established. The reason leading to the drop of water wall coating was analyzed. Calculation results showed that temperature gradient decreases from the coating to the inner wall of the tube,and the thermal stress of the interface between the coating and water cooling wall is affected by the structure of the water-cooled wall and the thermal expansion coefficient. Thermal stress is the main cause of coating spalling. The thicker the coating is, the higher the inteffaeial thermal stress is. When the thermal expansion coefficient of coating is smaller than that of matrix, the inteffaeial stress increases with the decrease of thermal expansion coefficient of coating. When the thermal expansion coefficient of coating is larger than that of matrix,the thermal stress at the interface increases first and then decreases.
作者
许文龙
李润璞
Xu Wenlong,Li Runpu(Everbright Environmental Protection Technology Research Institute （Nanjing） Co. , Ltd. , Nanjing 210000, China)
出处
《能源与环保》
2018年第8期59-63,68,共6页
CHINA ENERGY AND ENVIRONMENTAL PROTECTION
基金
反应塔钢结构轻量化研究及优化设计(HJKJ18007)
关键词
水冷壁
涂层
热应力
温度场
water cooled wall
coating
thermal stress
temperature field
