针对某炼油厂柴油加氢裂化装置高压换热器因结垢而导致换热效率降低、反应器入口分配器等设备结垢的现象,在装置检修期间取样分析。对所取垢样进行甲苯抽提处理后采用X射线荧光光谱仪（XRF）、扫描电子显微镜（SEM）和X射线衍射仪（XRD）等手段进行检测。结果表明：垢样由相对疏松结构和一层致密结构组成,疏松结构主要以含铁、硫元素的垢物组成,而致密结构主要以含铬、铁、硫和氧元素的垢物组成。垢样的主要无机成分为Fe（x）S（y）和Fe（x）Ni（z）S（y）,还含有少量含硅、钠和铝的无机物,有机垢可忽略。对此,建议炼油厂加注阻垢剂以抑制高压换热器或其他设备结垢的速率,跟踪计算换热器运行的垢阻,实现结垢速率可控,待装置正常停工检修时视结垢情况进行换热器的清洗。

In view of the phenomenon that heat exchange efficiency of the diesel hydrocracking high pressure heat exchangers in a refinery reduced and scaling in reactor inlet distributor and other equipment,the sampling analysis was conducted accompanied by shutdown of hydrocracking unit.The X-ray fluorescence spectrometer（XRF）,scanning electron microscope（SEM） and X-ray diffractometer（XRD） etc.were carried out to analyze scale sample after toluene extraction.The results showed that the scale was composed of relatively loose structure and a layer of compact structure,and the loose structure was mainly composed of scales containing Fe and S elements,but Cr,Fe,S and O elements for scales of compact structure.The main inorganic components of scale were Fe（x）S（y） and Fe（x）Ni（z）S（y）.In addition,it also contained a small amount of inorganic materials containing Si,Na Al,and little organic scale could be ignored.In this regard,it is suggested that the refinery should inject scale inhibitor to inhibit the scaling rate of high pressure heat exchanger or other equipment,and realize controllable scaling rate by tracking and calculating the scaling resistance of heat exchangers.The heat exchangers will be cleaned depending on the scale when the equipment is normally shut down for maintenance.