常压塔顶换热器系统流动腐蚀失效分析及预测研究  

Analysis of flow corrosion failure of atmospheric distillation tower overhead heat exchanger system and prediction study

作　　者：偶国富[1,2] 王凯[1] 朱敏[1] 孙彦霖 孙利[1] 

机构地区：[1]浙江理工大学流动腐蚀研究所,浙江杭州310018 [2]杭州富如德科技有限公司,浙江杭州310018

出　　处：《石油化工腐蚀与防护》2015年第6期1-5,共5页Corrosion & Protection In Petrochemical Industry

基　　金：国家自然科学基金资助项目(U1261124);浙江理工大学科研启动基金(15022014-Y)

摘　　要：针对某炼油厂的常顶换热器频繁失效的问题,首先运用化工工艺模拟软件仿真获得了常压塔顶换热系统的物性参数及油、气、水三相分率随温度的变化关系,并通过计算得出常压塔顶换热系统露点温度和NH_4Cl的结晶温度,其次运用传热计算软件对常顶换热器进行传热计算,获得了换热器管、壳程的流体以及管壁的温度分布规律,并通过对失效换热器解剖分析,验证预测结论的可靠性。结果表明:常顶换热器失效的主要原因是露点腐蚀及NH_4Cl结晶垢下腐蚀,其中HCl露点腐蚀是造成换热器管束腐蚀的最直接因素;在选取的工况下,换热器中露点温度为105.5℃,主要出现在距离换热器壳程进口1.2 m处;NH_4Cl结晶温度为113℃,主要出现在距离换热器过程进口0.6 m处的位置。In a case study of frequent failure of overhead heat exchanger of atmospheric tower in a refinery, the physical parameters of atmospheric tower overhead and the temperature variation relations of oil, gas and water with temperature are simulated with chemical process simulation software, and the dew point temperature and NH4 Cl crystallization temperature are worked out by calculation. In addition, heat transfer calculation software is applied to get the temperature distribution of tube and shell sides of overhead heat exchanger through heat transfer calculation. The correctness and reliability of the prediction is verified. The results indicate that the dew-point corrosion and NH4 Cl under-deposit corrosion are two main culprits for the failure of overhead heat exchanger of atmospheric tower, in which the HCI dew-point corrosion is the most direct cause for heat exchanger corrosion. Under the selected conditions, the dew-point temperature in heat exchanger is 105.5 ℃ which mainly appears 1.2 m from the inlet of shell side; and the NH4Cl crystallization temperature is 113 ℃, which appears 0. 2 m from the inlet of shell side.

关 键 词：常顶换热器 工艺模拟 传热计算 腐蚀预测 

分 类 号：TE986[石油与天然气工程—石油机械设备]