【作者】 黄军辉；

【导师】 偶国富；

【作者基本信息】 浙江理工大学 ， 机械电子工程， 2011， 硕士

【摘要】 随着炼油装置的大型化、原料油劣质化和运行工况苛刻化的发展,作为加氢裂化装置的重要设备之一,加氢反应流出物空冷器(REAC)长期承受高压、临氢工况,含氯原料油加工过程中频繁发生了因管束局部穿孔泄漏引起的非计划停工事故,损失惨重。为解决管束的频繁失效问题,通常做法是材质升级,成本巨大,同时升级后的管束也出现了多种流动腐蚀失效形式,因此,研制适用于苛刻工况下的空冷器管束,具有重大的学术理论和工程应用价值。本文针对含氯原料油加工过程中普遍出现的管束泄漏现象,采用工艺过程分析、流动腐蚀机理和失效案例解剖验证相结合的研究方法,确定了含氯原油加工入口管束的失效机理为NH4Cl沉积导致的局部腐蚀;提出了REAC第一管层采用内衬316L不锈钢复合管的管束结构,并针对复合衬管的结构和形式建立了力学模型;运用有限元分析软件ANSYS开展了实际运行工况下管束力学行为研究,获得了不同运行工况下的管束易失效模式,提出了评价复合衬管质量的力学性能指标;利用ANSYS非线性分析功能研究了复合衬管拉拔塑性成形过程,分析了胀头直径、摩擦系数、间隙等参数对成形效果的影响;对REAC管箱焊接、质量评定、检验检测等关键制造技术进行了分析,测试复合衬管试样获得的结合强度和传热性能等指标均符合国家相关标准和要求,满足和验证了管束质量并取得了成功的工程应用。本论文的创新性工作:综合分析了管束的流动腐蚀失效机理,提出了局部复合衬管形式的空冷器结构,进行了复合衬管结构形式分析和优化,并对实际运行过程中的管束热应力分析确立管束失效行为;分析了不同制造工艺参数对复合衬管塑性成型效果的影响,为实际工程制造提供了理论和数据基础。研究成果示范应用过程中经济效益明显,具有一定的创新性。更多还原

【Abstract】 As one of the most important equipment in hydoroprocessing plant, the reactor effluent air cooler (REAC) confronts the condition of hydrogenation process, high pressure and changing temperature, following the development of oil refineries. The unplanned shutdown of equipment which is attributed to the local corrosion of air cooler tubes results in a great loss for the enterprises during processing the crude oil containing chloride. The routine way by improving the materials of tubebundles comes across the cost problem and other failure styles. Therefore, designing and producing a new tube style that is applicable to the harsh running condition of REAC is quite valuable for the oil refineries.The technological process, flow induced corrosion mechanism and anatomy of tubes were analyzed according to the the actual failure cases of leakage in REAC tubebundles. It indicated that the corrosion failure style of tubes that attribute to the local corrosion resulted from ammonium chloride (NH4Cl) deposition. It is proposed a structure of 316L stainless steel lined tubes in REAC to solve the problem of corrosion failure induced from NH4Cl deposition. The structure and mechanical model of lined tube were analyzed by using finite element method. The mechanics behavior and the failure style of tube under different condition was obtained in the finite element analysis software ANSYS. The criteria of mechanic properties were proposed to assess the quality of tubes. The non-linear forming procedure of REAC lined tubes was studied by using ANSYS according to the different forming parameters such as drawing head diameter, friction coefficient and gap, etc. By analyzing the seal welding of tube-tubesheet, heat treatment examination and inspection after manufacture, it proved that the results meet the requirement of bonding strength and heat transfer properties according to the national and professional standards. It certified the stainless steel lined tube qualifies the request of engineering application.The innovative work in this thesis is concluded as follows: the flow induced corrosion failure style in REAC tubes was determined through the corrosion mechanism study. A structure of stainless steel lined tube was proposed to improve the reliability of REAC system. The structure study and mechanic optimization were executed. The behaivior and mechanic status of lined tube were simulated according to the actual running condition. There is also special work of forming effect analysis of different manufacture parameters that is useful for the practical engineering application. The specimen of lined tubes were executed and tested through national standards, of which the result qualified the requirement in engineering application and achieves the economic efficiency.更多还原