半埋热油管道传热研究

受飓风、暴雨、泥石流等恶劣天气的影响，埋地管道可能局部处于半掩埋状态。目前半埋管道传热计算多采用“线性插值”模型。建立了半埋热油管道的流（空气水）—管—土耦合传热机理模型，并利用数值模拟手段对不同条件下管道的传热特性进行了研究。结果表明，管道的总传热系数、出口温度和土壤蓄热量与管道的相对埋入面积呈明显的非线性关系；线性模型与机理模型的计算结果在趋势与数值方面均具有较大偏差；管道刚好完全掩埋时与完全不掩埋时相比，总传热系数出口温度的差异较大，且管径越大，差异越显著；当环境流体的温度较低时，管道出口温度对相对埋入面积更敏感。

Study on Heat Transfer of Partially Buried Hot Oil Pipeline

As a result of bad weather，such as hurricane，storm or landslide，some part of buried pipeline may be in a semiburiedstate. Currently the“linear interpolation”model is used to calculate the heat loss of partially buried pipe. A mechanismmodel of heat transfer of fluid（air/water）-pipe-soil coupling is developed，and the thermal behaviors of pipeline are studiedby numerical simulation. The results show that the changes of the overall heat transfer coefficient，outlet temperature and soilheat storage of pipeline with the fraction of outside surface of pipe in touch with soil have obvious non-linear characters，boththe trend and value of the linear model deviate from that of the mechanism model greatly. There are significant differences inthe overall heat transfer coefficients/outlet temperatures between the pipe completely exposed to the surrounding fluid and thatjust covered by soil. The bigger the pipe diameter is，the greater the differences are. When the temperature of the surroundingfluid is lower，the outlet temperature is more sensitive to the fraction of outside surface of pipe covered by soil.