Study On The Model For Restart Of A Waxy Crude Oil Pipeline

Began with the basic law, a more integrated model of restarting was proposed based on the thermal-hydraulic coupling of crude oil in the pipeline and coupling of crude oil to medium outside the pipeline.According to the Mathematical Model of steady temperature field formed by pipelines running steadily ,Non-steady temperature field during shut down of pipelines and the restart of pipelines, the finite element method, shock waves and Double-characteristic method was adopted to solve heat differential equation, and the relevant software was programmed. The idea that the different burial depth using different radius of heat influence was first proposed, which can not only make the programme simpler, but also make the results more accurate. And it is very important for the economic and safe functioning of the pipeline.A real pipeline restarted under constant applied pressure in different seasons was simulated with this software, and the results showed that under the situation that the temperature of cold oil was high; the flow rate increased all the time until to constant;but the change for the end of pipeline's temperature showed two tendencies.The affecting factors of flow rate and temperature were also discussed. When starting progress was over, the final results were compared to the parameters of stable state and showed that the errors between them were reasonable in any situation.