火灾下埋地管道温升计算中地表边界条件研究

Study of the Ground Boundary Conditions When the Buried Pipeline's Temperature is Calculated on Fire

地面发生火灾时,土壤原有的热平衡被破坏,新的温度场建立起来,影响土壤中敷设的油气管道的温度分布。针对这一情况,建立了非稳态传热模型。分析不同的火灾类型,采用不同的边界条件对模型进行了数值模拟。在VB环境中编制相应的软件,实现基础数据输入、温度场迭代、结果输出等功能。通过分析模拟结果,确定了此类模拟中各种边界条件适用的范围。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的依据。

When the ground surface is on fire, the thermal balance of soil is destroyed, so the new temperature field will be built up, thus affecting the temperature of the buried pipeline. In light of this case, the variety is analyzed, an unstable thermal model established. By adopting boundary different conditions, the model is numerically simulated. A software in VB visual studio is programmed to input necessary data and realize the iteration of the temperature field and the output value in different periods of time. The result tells us which kind of boundary conditions is appropriate. The establishment of this model has laid a scientific base for later research on the effect of a ground surface fire on the medium during transportation in buried pipeline.