直接电加热过程海底管道热力学特性研究

Research on the Thermodynamic Property of Subsea Pipeline during Direct Electrical Heating Process

针对直接电加热引起的海底管道热力学问题,以管道停输工况为例,采用有限元软件ABAQUS建立海底管道稳态传热有限元模型,在此基础上,基于管土相互作用建立海底管道整体有限元模型,开展海底管道整体热应力与热屈曲分析。研究结果表明:在直接电加热过程中,半埋管道的温度略高于悬跨管道;直接电加热会增加管道的整体应力水平,但远小于管道屈服应力;当初始缺陷过大时,管道会在直接电加热过程中产生热屈曲现象。

For the thermodynamic problem of subsea pipeline induced by direct electrical heating, and taking pipeline shutdown working condition as an example, finite element software ABAQUS is adopted to establish the steady-state heat transfer finite element model of subsea pipeline. On this basis and considering pipe-soil interaction, the finite element model of subsea pipeline is established to analyze the heat stress and thermal buckling of subsea pipeline. The research results show that the temperature of partially-buried pipeline is slightly higher than that of suspended pipelines during direct the electrical heating process. Through direct electrical heating process, the whole stress level of the pipeline is increased, but it is still far less than the yield stress of pipeline. When the excessive initial fault is too large,thermal buckling of pipeline occurs during the direct electrical heating process.