渣油加氢装置高压进料泵流量降低原因分析

摘要

某炼油厂渣油加氢装置两台高压进料泵电机出现超电流和流量降低的现象,泵的流量最低至60 t/h。分析了原料密度、黏度对泵性能的影响,认为原料酸值高（折算原料中环烷酸的酸值高达0.66 mgKOH/g）是造成高压进料泵内件腐蚀的主要原因。从泵出口的部分介质通过腐蚀间隙增大的叶轮口环等部件回流到泵的入口,导致泵内循环量增加,泵出口总流量下降进而导致电机超电流。通过控制原料的总酸值不超过0.3 mgKOH/g和原料储存按照一定比例掺兑加工等措施,有效地缓解了此类现象的发生。%The motors and two HP feed pumps in the residue oil hydrotreating unit of a refinery experienced electric current overrun and flowrate reduction,and the flowrate of pump went down as low as 60 t/hr.The analysis of impact of feedstock densities and viscosity as well as pumps themselves concluded that the culprit of corrosion of HP feed pumps was the high TAN of feedstock(0.66 mgKOH/g).Part of medium from outlet of pumps flowed back to the inlet through the enlarged corrosion crevice of blade ring,resulting in the increased internal pump circulation,reduction of pump discharge flowrate and electric current overrun of pump motors.Such problems have been mitigated by control of TAN of feedstock within 0.3 mgKOH/g and blending ratio of feed.