常减压蒸馏装置长周期运行的影响因素及对策

Factors Affecting Long- term Operation of Atmospheric- vacuum Distillation Unit and Countermeasures

加工高硫低酸原油设计的常减压蒸馏装置存在加工原油劣质化、塔顶换热器低温腐蚀严重、重油高温部位硫腐蚀、初馏塔压降快速增加影响产品质量、高温油泵故障率高等影响安全平稳运行的因素。为提高长周期的运行水平,利用检修机会针对性地消除影响装置安全平稳运行的瓶颈,完善低温部位工艺防腐措施、改进低温换热器材质和型式,对高温硫腐蚀部位进行材质升级,增加初馏塔跨线、实现不停工处理初馏塔压降高,对高温机泵更新或技术改造、提高机泵运行可靠性,提高技术管理水平,采取上述措施后常减压蒸馏装置运行的本质安全得到较大提高,实现四年一修的长周期运行目标。

As the crude oil became increasingly poor for the atmospheric - vacuum distillation unit designed for processing high - sulfur low -TAN crude oil, tower overhead heat exchanger suffered from serious low -temperature corrosion and sulfur corrosion at high- temperature heavy oil location. In addition, the rapid increase of pressure drop in preliminary tower affected the product quality and increased the abnormal operation of high - temperature oil, which influenced the safe stable operation of the unit. To improve the long - term operation of the unit, a series of measures have been taken to debottleneck the safe operation of the unit during the maintenance, such as： process corrosion prevention measures have been modified for the low- temperature section, the materials and type of heat exchangers for low - temperature service are improved, the material of the high - temperature sulfur corrosion section is upgraded, a cross line is provided for the preliminary tower to tackle the high pressure drop problem without shutdown of the unit, the high -temperature motors and pumps are replaced or revamped by the new technology to enhance the operation reliability and management is further improved. After taking of the above measures, the intrinsic safety of the atmospheric - vacuum distillation unit is greatly improved, and the unit only needs to be shut down for maintenance once in every four years.