Design Of Corrosion Monitoring System On Yan’an Refinery’s Atmospheric Pressure Unit

Atmospheric pressure unit is the place of crude oil processing, and static equipment occupies a large proportion in it. In the corrosive crude oil processing, the main problem is the failure of corrosion, which results in not only a waste of material, but also may lead to atmospheric pressure unit unplanned stoppage. The normal operation of the atmospheric pressure unit affects the crude oil’s subsequent processing and the continuous operation of the whole refining company, so the economic losses caused by unplanned stoppage is huge. In order to the long period of operation in refining company, it is essential to carry out the corrosion mechanism and protection technology investigation as well the research of corrosion monitoring system in atmospheric pressure unit.By collecting the parameters of crude oil processing atmospheric pressure system in22refining companies which are under CNPC or Sinopec, obtained the typical technological process and parameters of the main equipments, and summarized the corrosion parts, corrosion mechanism, corrosion types and protective measures. Combined the technological process of atmospheric pressure unit in Yan’an refinery which outputs three million tons per year and according to the frequency and severity of corrosion problems in the unit during operation, divided the crude oil atmospheric pressure processing system into eight subsystems. Chosen different corrosion monitoring methods for equipments, pipelines and other corrosive problems by using the latest technology of corrosion monitoring and combining the feasibility of corrosion monitoring point arrangement in field equipment. Established a corrosion monitoring system which covers eight subsystems of atmospheric pressure unit in Yan’an Refinery.The corrosion monitoring system provides a theoretical basis for corrosion monitoring of atmospheric pressure unit in Yan’an Refinery. It establishes the early warning system in equipment corrosion problems and keeps track of the corrosion rate and understands the reliability of equipment operation. The system will be in favor of the normal operation of Yan’an Refinery atmospheric pressure unit after it is put into use. It will predict the tendency of unit corrosion timely in order to adopt reasonable measures to prevent corrosion. This system can minimize the economic loss and dangerous accidents which are caused by system can minimize the economic loss and dangerous accidents which are caused by corrosion, guarantees the safety of units operation, and extends the period of operation effectively in Yanchang refining company.