高压加氢装置处理进料换热器堵塞原因分析

Analysis of blocking causes of feed heat exchanger in HP hydrotreating unit

高压加氢装置处理进料换热器换热效率降低,起初怀疑双壳程隔板密封失效、介质短路。通过装置停工对换热器进行检修,同时检查工艺流程和工艺操作记录,查明了换热器换热效率降低的原因。高压加氢装置加氢原料品质逐年变差,工艺操作未严格控制原料过滤器的过滤操作,打开原料过滤器副线维持操作,造成管束堵塞是换热器换热效率下降的主要原因;高压换热器双壳程隔板密封条安装保护不到位、局部变形是次要原因,该部位在介质严重堵塞情况下发生短路,加剧了换热效果下降。针对故障原因采取了加强高压加氢装置工艺原料品质控制,加强原料过滤器操作控制,加强检修、维修质量控制等措施,解决了换热器管束结垢失效问题。

When the heat exchange efficiency was low in the feed exchanger of high pressure hydrotrea- ting unit, it was suspected that the failure of double-pass partition seal and media shut-cut may be the causes. The exact causes of low heat exchange efficiency of heat exchanger was found out in the maintenance during the unit shutdown and examination of process flow and operation record data. The analysis of process opera- tion, equipment construction and quality inspection in maintenance concluded that the major culprits of reduc- tion of heat exchange effi^iericy were the deterioration offeed qu＇ality of hydrotreating unit, failure to strictly control the feed filter operation, operating the filter by-pas line and the resulted tube blocking. In addition, inappropriate installation of double-pass partition seal and deformation also contributed to the reduction of heat exchange efficiency. The short-cut of meadia in serious blocking condition has accelerated the heat treansfer efficiencty reduction. The problem of fouling blocking failure of heat exchanger has been solved by control of HP hydrotreater feed quality, control of feed filter operation and control of maintenance quality.