腐蚀环境下石化压力仪表力学-化学耦合分析  

Mechanical-chemical Coupling Analysis of Petrochemical Pressure Sensor Under Corrosive Environment

作　　者：代思洋 曹德舜 李娜 王昊 Dai Siyang;Cao Deshun;Li Na;Wang Hao(State Key Laboratory of Chemical Safety,Shandong,Qingdao,266104;SINOPEC Research Institute of Safety Engineering Co.,Ltd.,Shandong,Qingdao,266104)

机构地区：[1]化学品安全全国重点实验室,山东青岛266104 [2]中石化安全工程研究院有限公司,山东青岛266104

出　　处：《安全、健康和环境》2025年第2期18-25,共8页Safety Health & Environment

基　　金：中国石化科技部项目(324103),石化仪控关键硬件故障预知与寿命预测研究。

摘　　要：石化压力仪表主要工作在复杂、恶劣的现场环境,其可靠性一直面临严重威胁。针对腐蚀环境下压力仪表关键单元芯体退化机理不清的问题,建立芯体有限元模型,借助热学-力学耦合分析,研究芯体的应力、温度和形变等参数分布,对比加载电流前后各参数的变化规律。进一步,利用力学-化学耦合分析,说明应力与腐蚀缺陷之间的相互作用机制,对比不同腐蚀深度和形变下芯体铝封装层最大应力的变化。结果表明,在未加载电流条件下,芯体铝封装层的应力分布相对均匀,但是在热稳态条件下,铝封装层的中心位置产生局部应力,中心和边缘位置的应力差最大达到2.8 MPa。更进一步,在高温和腐蚀的共同作用下,铝封装层发生腐蚀缺陷,腐蚀缺陷中心位置出现最大应力,应力在腐蚀缺陷中心两侧呈对称分布,且最大应力随着腐蚀缺陷深度的增加而增大,最大应力数值相比热稳态条件增大近6.1%。铝封装层的受力不均会加速材料退化,引发芯体产生塑性形变或断裂,进而无法准确感知压力。研究结果可为石化压力仪表性能分析提供参考,也可为其他行业压力仪表的可靠性提升提供数据支撑。Petrochemical pressure sensor mainly operates in complex and harsh on-site environments,where its′reliability has always been seriously threatened.Aiming at the unclear degradation mechanism of pressure sensor under corrosive conditions,a finite element model was established.A thermal-mechanical coupling analysis was conducted to examine the distribution of parameters such as stress,temperature,and deformation within the core body,comparing the variation of each parameter before and after loading current.Subsequently,the interaction mechanism between thermal stress and corrosion defects was elucidated through a mechanical-chemical coupling analysis.The variations in the maximum stress of the core body′s aluminum encapsulation layer under different corrosion depths and deformations were compared.The results show that the stress distribution of the aluminum encapsulation layer of the core body is relatively uniform under the condition without current loading.However,under the thermal steady-state condition,the local stress occurs at the center position of the aluminum encapsulation layer.The maximum stress difference between the center and the edge positions reaches 2.8 MPa.Furthermore,under the combined effects of high temperature and corrosion,the aluminum encapsulation layer develops corrosion defects.The maximum stress is observed at the center of these defects and is symmetrically distributed on either side of the defect′s center.As the depth of the corrosion defect increases,so does the maximum stress,which escalates by nearly 6.1%compared to the thermal steady-state condition.Uneven stress distribution across the aluminum encapsulation layer expedites the material degradation,potentially leading to a plastic deformation or fracture of the core body,thereby hindering accurate pressure sensing.The research results provide a reference for the performance analysis of petrochemical pressure sensor,and also provide data support for the reliability improvement of pressure sensor in other industries.

关 键 词：压力仪表 芯体 力学-化学耦合分析 腐蚀缺陷 应力集中 

分 类 号：TH70[机械工程—仪器科学与技术]