Estimation Forthe Process Pipes' Corrosion Life And Defect Simulation In The Atmospheric And Vacuum Distillatio N Unit

Pipes are widely applied in various sectors, which play an important role in Oil and Chemical industries. If the sulphur content in the raw oil is too high, it will corrode the pipes seriously, and shorten their service life. The pipes'residual life evaluation is necessary to grasp the corrosion conditions and use the pipes as long as possible without failure in service. The pipes' failure probability was simulated and the pipelines' service life was predicted with the Monte-Carlo method using the Matlab sofeware, based on the analysis to the field data applying the methods of probability and statistics. The Main research contents were summarized as follows:1. The risk analysis of pipelines was made, and the corresponding manipulative measures were put forward, and the Pipeline Integrity Management concept was introduced, which made the process pipelines'management more comprehensive and more systematical.2.The corrosion types, crrosion effect factors and mechanisms of process pipelines were analysed, and the main anticorrosion measures were summarized, based on extensive collecting information at home and abroad, and investigation in spot field.3. The process pipelines'corrosion data base was made using the Access sofeware, based on the process pipelines'thickness data from a Petroleum Refinery.4. The process pipelines' thickness data was collected and the corrosion rate' distribution was obtained using the Excel sofeware; data fitting was made to the corrosion rate' distribution using the Matlab sofeware, the results indicated that the corrosion rate' distribution obeied the normal distribution mainly.5. Estimation for residual life was made to all the pipes of the atmospheric and vacuum distillation unit in a Petroleum Refinery. The pipes' failure probability was simulated, and the pipelines' corrosion rate distribution and service life was made, which raw oil's acid value is 1 mg KOH/g and contains 1% sulphur content, with the Monte-Carlo method using the Matlab sofeware, according to the corrosion rate' normal distribution model, the results and actual cases were basically matched. Further, the influence of localized corrosion to the pipes'life was simulated on this basis, and the results had certain reliability.