直埋LNG管道周围土壤冻融相变数值研究

Numerical Research on Freeze-thaw Phase of Soil around the Buried LNG Pipeline

采用有限容积法建立多孔介质相变自然对流换热模型,以直埋LNG管道为例,采用SIMPLER算法进行求解,数值计算了地表温度周期性波动条件下,埋地输冷管道非稳态传热过程,得到了不同季节管道周围土壤温度场及冰水相变界面分布规律。研究表明:在地表温度的周期波动下,LNG管道周围土壤温度场波动减小,且随着LNG冷量的不断释放,管道周围出现较大范围的冻土圈。

Finite volume method was used to build the porous media natural convection heat transfer model. Taking the buried LNG pipeline as an example, unsteady-state heat transfer process of the buried cold pipe was calculated under surface temperature cyclical fluctuation conditions by SIMPLER algorithm. The distribution law of the temperature field of the soil around pipeline in different seasons and ice water phase change interface was gained. The research shows that temperature field fluctuation of the soil around LNG pipeline decreases under the surface temperature cycle fluctuations, and a larger range of frozen soil around pipeline arises with continuous releasing of LNG cold energy.