埋地热油管道预热启输过程外界气温及预热水温对土壤温度场的影响

THE INFLUENCE OF AMBIENT TEMPERATURE AND PREHEATING WATER TEMPERTURE ON TEMPERATURE FIELD OF SOIL DURING PREHEATING BURIED HOT CRUDE OIL PIPELINE FOR STARTUP

在建立管道和土壤的非稳态传热模型的基础上,重点考虑土壤和管道的初始温度分布、外界大气温度的周期性变化、预热热水的温度变化,以及由于空气和热水温度变化引起的空气和热水热物理属性变化导致空气与土壤表面和热水与管道内壁之间对流换热系数的变化等诸多因素对土壤温度场建立过程的影响。

It is one of the most important works that pipeline and soil are preheated by hot water before pipeline startup. The establishment of soil temperature field during preheating is an unsteady heat transfer process, which is tightly related to both initial temperature distributions of soil and pipeline and the changes of ambient and water temperature. Based on the unsteady heat transfer model for soil and pipeline, the influence of initial temperature distributions of soil and pipeline, periodical change of ambient temperature, temperature change of preheating water, the changes of thermal property of air and hot water resulting in the change of heat transfer coefficient between air and soil top surface, and between hot water and pipeline inside wall on the process of heat transfer in soil and pipeline were analyed.