输油管道非稳定热力过程数值分析

Numerical Analysis of Non-steady Thermal Process for Oil Pipeline

在埋地热油管道的运行中,因其输送工艺的变化,如反输、停输和启动等,管内原油与土壤中的热力平衡状态被破坏,油温及土壤温度将重新分布。因而,研究这一非稳定热力过程就必须对非稳定温度场进行分析。通过采用双极坐标保角变换的方法,将半无限大土壤温度场转化为有限场,提出了热油管道非稳定热力过程计算方法。以花格线和中洛复线反输运行试验数据与该方法计算的结果进行了验证,结果表明,数值计算结果与实测结果非常吻合。认为该计算方法可用于热油管道的停输、启动、反输等非稳定热力过程的模拟计算。

When buried hot oil pipeline experiences any change in transmission process, e. g. reverse pumping, shut-down, start-up, etc. , the thermal equilibrium is destoried between the oil in pipeline and the surrounding soil, and the oil temperature and soil temperature redistribute. As a result, in order to study this non-steady thermal process, non-steady temperature field has to be analysed. Using the method of confor-mal transformation in bipolar coordinates, the semi-infinitely large temperature field of the soil is transformed to a finite field, and the method is introduced for calculating the non-steady thermal process for hot oil pipeline. Verifications are made, using this calculation method, based on the experimental data measured during reverse pumping in Hua-Ge Line and Zhong-Luo Looping Line. The numerical caculation is proved quite identical with the actual measured results, and this calculation method is considered applicable to the simulation of non-steady thermal processes for hot oil pipelines such as shut-down, start-up, reverse pumping, etc.