交替方向隐式迭代法计算火灾下埋地管道温度

Calculation of temperature field for buried pipelines in case of fire by alternative direction implicit iteration

埋地输油管道在运行中有时会遇到地面火灾,土壤中的热力平衡被破坏,土壤温度重新分配,从而进一步影响管壁温度分配。针对地面发生火灾这一情况,分析非稳态热力过程,建立了热力计算模型。运用交替方向隐式迭代法对计算模型进行计算。在差分网格的划分中使用了混合网格法。在VB环境中编制了相应的软件,实现基础数据输入,温度场迭代、结果输出等功能。这一模型的建立,为后续的管内输送介质温度分配的研究提供了科学依据。

In case of fire, the thermal balance of soil around an underground oil pipeline will be lost, and the soil temperature will be redistributed. Accordingly, the temperature distribution of the pipe wall will be influenced. In this paper, the unsteady heat transfer to an underground oil pipeline in case of fire was analyzed, and a calculating model was established. The temperature field of the pipeline was calculated by the ADI （Alternative Direction Implicit Iteration）. A mixed mesh method was presented, which uses rectangular meshes in the inner field and normal line meshes near the pipe wall. A software in VB visual studio has been programmed to input necessary data, finish iteration and output temperature values at different time. The establishment of this model has laid the scientific base for later research on the effect of a ground surface fire on the medium transported through the buried pipeline.