关键词: 埋地管道, 停输, 有限差分法, 有限容积法, 非稳态传热, 数值模拟

Abstract: For the research of buried hot oil pipelines at shutdown, it was established that normal operation of buried hot oil pipelines and unsteady-state heat transfer model at shutdown with finite volume method and finite difference method. It considered that the changes of crude oil viscosity, density, specific heat and thermal coefficient with temperature in normal operation and shutdown, and considered oil latent heat of solidification impact on temperature drop at shutdown. Land surface temperature bases on periodic boundary conditions. And temperature drop of hot oil pipelines which are put into operation and has been operating until the march of the second year was simulated at shutdown. The research shows that there are many differences about oil curing at each section of pipeline and temperature field of soil obviously changes with shutdown time prolonged. Shutdown time is reasonably made sure, which provides theoretical guidance for pipe safe start.

Key words: Buried pipeline, Shutdown, Finite difference method, Finite volume method, Unsteady-state heat transfer, Numerical simulation