常减压蒸馏装置腐蚀分析与检测

Analysis of Corrosion in Atmospheric-vacuum Distillation and Testing

国内炼油企业因腐蚀问题影响装置稳定运行的情况十分普遍,严重者造成安全事故。加工劣质油后,出现腐蚀事故的频次及程度不断增加,从而各炼油企业对防腐检测、防护及管理工作提出了更高的要求。对常减压蒸馏装置存在的主要腐蚀问题进行了分析,通过总结定点测厚工作存在的缺点和不足,提出全新的腐蚀检测理念。腐蚀检测通过对设备原始资料进行统计分析,识别腐蚀存在部位及表现形式,分析设备风险等级;根据腐蚀机理和RB I风险分析结果,提出主要设备的测厚布点,对管线进行层次划分并制定检测原则;指出工艺防腐效果检测与腐蚀检测的关系,对原油质量及电脱盐控制、塔顶低温部位防腐监测、在线探针监测、不定期设备腐蚀检测管理与分析提出建议,为常减压蒸馏装置腐蚀检测与管理提供经验。

When the refinery began to process low - quality crudes, the occurrence frequency of corrosion - related accidents and corrosion degrees are increased, which demands higher requirements for corrosion testing, corrosion protection and corrosion management of oil refining companies. The main corrosion problems in the atmospheric - vacuum distillation units are analyzed, inefficiency and shortcomings in fixed -point thickness measurement are summarized, and new corrosion testing concepts are proposed. In corrosion testing, the original data of equipment are first systematically analyzed to know the corrosion locations and forms and analyze the risk class of equipment. Based upon the corrosion mechanisms and results of RBI risk analysis, the thickness measurement points distribution of main equipment are proposed, piping is classified and associated testing principles are determined. The relationship between process corrosion prevention testing and corrosion testing is described. Recommendations are proposed for control of crude quality and electric desahing, monitoring of corrosion in tower overhead low - temperature section, online electrical probe testing, random equipment corrosion testing management and analysis, which provides good experience for corrosion testing and corrosion management of atmospheric - vacuum distillation units.