泄漏检测与维修技术在芳烃歧化装置的应用

The Application of Leakage Detection and Repair Technology in Aromatic Disproportionation Units

采用泄漏检测与维修(LDAR)技术,对芳烃歧化装置无组织泄漏情况及挥发性有机化合物(VOCs)的无组织排放量,进行全面检测和统计分析,分析泄漏的原因并通过维修减少泄漏。芳烃歧化装置容易泄漏的元件主要为连接件和开口管线,主要分布在分馏区的泵区和换热器区;泄漏浓度SV≥5000μmol/mol的泄漏密封点对总泄漏量的贡献达到了67%。泄漏量大点位主要分布在分馏塔泵区、分馏塔换热区和罐区,主要为连接件、开口管线和阀门等元件,是造成泄漏排放的主要部分。总计检测25501个设备密封点,整体泄漏率为0.69%,VOCs泄漏排放量总计达到43.9t/a,设备管阀件泄漏造成的加工损失率为0.0055%,泄漏点不停工维修修复率为45.2%,泄漏点停工维修修复率为91.5%,停工维修后整体泄漏率降至0.38%;VOCs减排量降至38.6t/a,减排率达到88%。

Using the leakage detection and repair technology,LDAR,technicians conducted a full detection and statistical analysis of uncontrolled leakage and uncontrolled discharge of volatile organic compounds（VOCs）from an aromatic disproportionation unit,examined the causes of leakage and proposed repair methods to reduce leakage.The main components of an aromatic disproportionation unit which are prone to leakage include connectors and open-ended pipelines,which are mainly located in the pump area and heat exchanger area of the fractionation area.Leak sealing points with leakage concentration SV ≥5000μmol/mol are responsible for67% of total leakage.Most major leaking points are located in the pump area and heat exchange area of the fractionating tower and the tank area and the main components prone to leakage are connectors,open-ended pipelines and valves.These technicians inspected a total of 25501 equipment sealing points and the overall leakage rate was 0.69%.VOC leakages totaled 43.9t/a and the rate of processing loss caused by equipment valve leakages was 0.0055%.The on-stream repair success rate of leaking points was 45.2% and the shut-down repair success rate was 91.5%.The overall leakage rate after shutdown repair dropped to 0.38%,VOC emission reduction fell to 38.6t/a and the emission reduction rate reached 88%.