延迟焦化装置运行问题分析及技术改造

摘要

This paper analyzed the operation problems of 1.2 Mt/a delayed coking unit in PetroChina Lanzhou Petrochemical Company and introduced the results after technical transformation.The problems in existing unit included:(i)high content of oil,COD and suspended matter in coke quench sewage,which was unable to reuse as a cold coke cutting water;(ii)coke fines in the sour water from fractionator overhead,and in coking gasoline and diesel,which influence long period operation of the downstream unit;(iii)design defects in process interlock of heating furnace,leading to an invalid use.To solve these problems,a cold coke sewage treatment system and a coke powder removing system were added.Then the treated cold coke sewage can be reused and the influence of coke fines on the operation for downstream unit is reduced;the interlocking mode of heater furnace was changed from"one-out-of-one"to "two-out-of-three",and is successfully applied after transformation.%分析了中国石油兰州石化公司1.2 Mt/a延迟焦化装置运行中存在的问题,主要为冷焦污水含油、COD和悬浮物含量较高,不能直接作为冷切焦水回用;分馏塔塔顶酸性水和焦化汽柴油携带焦粉,影响下游装置的长周期运行;加热炉工艺联锁存在设计缺陷,不能有效投用.针对这些问题,通过技术改造,增上冷焦污水处理系统,处理后的冷焦水实现了回用;增上酸性水除焦粉系统及焦化混合汽柴油过滤器,减少了焦粉携带对下游装置的影响;加热炉工艺联锁由"一取一"改为"三取二",实现了联锁的有效投用.