The Flow Safety Evaluation Of QingJing Crude Oil Pipeling

Most of crude oil in our country is waxy oil,high solidifying point,poor liquidity under normal temperature and high energy consumption of the pipeline,oIn the process of transportation,it always uses heat treatment.Multiple parameters that effects flow exist in the process of heat treatment transportation.These parameters will effect the performance characteristics of pipeline。How to judge these uncertain factors effect the running safety of low throughput pipeline,it is very very important significance to ensure the running safety of pipeline。The working characteristic curve of hot oil pipeline exist instability workspace,when the running throughput is in the throughput range of instability workspace,if the running throughput is lower than the critical throughput,pipelin will be the unstable state.In this paper we will obtain pipeline heat-transfer model,by calculating pipeling thermal and hydraulic in the condition of steady state and unsteady state.The article takes that the running data of northeast pipelines Tieling to Shenyang who carrying the Daqing oil as example,than we overall considerate the affecting relationship of various factors on the unstable state critical throughput.Reliability method was applied to crude oil pipeline safety evaluation,and the improved monte carlo sampling method was used to conduct the evaluation of computing.Among them,the temperature drop in the output calculation stops adopted a lumped heat capacity algorithm based model fitting technique parameters in real time,which greatly improves the speed based on numerical simulations.With crude oil pipeline flow three failure modes of failure probability,as evaluation index,that we develop a software for crude oil pipeline safety assessment.This software has friendly interface,can be analyzed for the condensing tube probability of any pipes,equipment reliability and pipeline operation condition.Finally,we can be the safety assessment analysis for Qinjing pipeline which is in running process of instability workspace in the past two years.Using the software calculates running safety condition of Qinjing pipeline.