催化裂化装置烟机结垢原因分析及应对措施

针对目前影响催化裂化装置长周期安全运行的核心设备之一——主风机组的烟气轮机存在的结垢问题,收集了国内37家炼油厂催化裂化装置的运行数据,分别从装置的操作条件、烟机的机械设计以及催化剂的使用3个方面进行了详细的对比分析,对烟机结垢的成因进行了探讨。结果表明,烟机结垢是一个多因素相互作用的结果,主要因素包括:烟机流道的流场不均匀、扰动大;烟机的叶型、叶片的表面粗糙度、轮盘冷却蒸汽流量及温度;平衡剂脱附的金属、烟气中的细粉(尤其是超细粉)与烟气中的水蒸气、硫等介质的相互作用,加剧了叶片表面的粗糙度,容易造成烟机结垢。基于对烟机结垢成因的分析总结,提出了减缓烟机结垢的改进措施。

CAUSES OF FCCU FLUE GAS TURBINE FOULING AND COUNTERMEASURES

Fouling on the flue gas turbine is a common phenomenon influencing long term operation of FCCU. Operation data of 37 sets FCCU were collected and discussed, including operation conditions, machine designs and catalyst usage etc., to investigate the reasons. The analysis showed that the turbine fouling is the result of a multi-factor interaction. The factors include non-uniform flow field in turbine channel, profile and surface roughness of blades, flow rate and temperature of steam for cooling disk, dropped metals from E-cat, interaction of fine (especial super fines) catalyst with steam and sulfide in the flue gas. These factors could aggravate the roughness of blade surface, resulting in fouling on the flue gas turbine. Based on these analyses, some countermeasures are provided to postpone fouling on the flue gas turbine.