埋地热油管道启输热力数值模拟

Numerical Simulation of Heated Crude Oil Pipeline at Starting

在综合考虑预热介质、管道、管道覆盖层以及半无穷大土壤的情况下,提出了埋地热油管道启输传热的数学模型,并在该模型中,将土壤物性参数视为随温度变化的函数,应用保角变换将半无穷大土壤区域变换成有限矩形区域。由Keller盒式积分法构造出了问题的差分格式,采用广义阻尼牛顿一拉夫逊法求解非线性差分方程组,得到了问题的数值解,并由算例验证了所述方法的正确性。

It possesses profound practical significance to study the thermal calculation of heated crude oil pipeline at starting both for determining starting time of delivering crude oil and ensuring safe operation of pipeline. In the light of the medium,pipeline,coatings and semi-infinite soil and their unstable heat transmission,a mathematical model for thermal calculations considering temperature dependent relative physical properties of soil is setup. By conformal transformation and cassette integration, the semi-infinite soil region is transferred into a definite rectangle region,this model can be used to do a series of numerical calculations by generalized damping Newton-Raphson method. The method derived is proved feasible by a practical example.