Research On Corrosion Monitoring And Safety Assessment Technology For Pressure Pipeline

Pressure pipeline,as the special pressure equipment,has potential leakage and explosion risk.With the increase of service time,a considerable part of the pressure pipeline is seriously corroded and has potential safety hazards.Once the pipeline fails,it will cause irreversible safety accidents and environmental pollution.This paper mainly studies the pressure pipeline.The simulation and experiment of corrosion monitoring based on FSM method and the research of pipeline safety assessment technology are carried out.The research of safety assessment technology mainly focuses on the dynamic risk evaluation of corrosion of pipelines and the prediction of residual service life of pipelines.The main research contents and results are listed as follows:(1)The multi-level grey dynamic evaluation of external corrosion of pipelines based on cooperative game is studied and put forward.According to the characteristics of external corrosion of buried pipelines,an evaluation index system of external corrosion of pipelines is constructed.Aiming at the problem of determining the weights of the indexes,a method based on cooperative game is proposed to determine the synthetic weight of each index.The subjective weights of the indexes obtained from expert qualitative analysis were quantified by applying improved analytic hierarchy process based on group decision-making.The objective weights of indexes were obtained by detecting real-time data information.The grey relational analysis method is introduced to pipeline corrosion evaluation field,so as to propose a multi-level grey dynamic evaluation of external corrosion of pipelines based on cooperative game,which provides a new solution to solve the complexity and uncertainty and timeliness of pipeline corrosion evaluation.(2)The feasibility of the FSM technology to classify and identify the defects of pressure pipelines is verified by simulation and experiment.The corresponding relationship between common defects of pressure pipeline and the change of FC caused by them is studied.The defect area,length,depth and defect boundary profile,which mainly affect the measurement results of FSM,are simulated and experimentally studied.The accuracy of FSM for identifying common defects in pipelines is obtained through experiments,and the value of correction coefficient in thickness loss formula is determined,which improves the accuracy of FSM technology for monitoring the depth of defects in pressure pipelines.(3)A method for predicting the residual service life of pipelines is studied and put forward.Due to a limited amount and random fluctuations of actual pipeline corrosion data,an unbiased grey and markov chain composite model is established to predict the residual service life of pressure pipelines.The prediction accuracy meets the accuracy requirements of engineering problems.The proposed model provides a new way to predict the residual service life of pipelines.