管道冬季泄漏土壤热波动及原油渗流数值计算

采用有限容积法建立埋地管道泄漏多孔介质流固耦合相变数学模型，对冬季热油管道不同位置泄漏前后大地温度场的变化及原油在土壤中的分布规律进行数值模拟。研究表明：管道泄漏后，一定时间内管道周围土壤温度波动剧烈，由于受环境温度的影响，泄漏前锋原油温降较快，很快达到凝点，并出现不同形态的动态凝油层，致使原油渗流速率降低，热影响区范围变化逐渐趋于平稳。且随泄漏位置的不同，地表温度变化及土壤中原油分布差异较大。应用分布式光纤温度传感技术检测管道泄漏是可行的。

CALCULATION OF THE THERMAL FLUCTUATION VALUE AND OIL SEEPAGE VALUE WHEN PIPELINE LEAKS IN WINTER

Distributed optical fiber temperature sensing is a cutting-edge technique in pipeline detection，which has not been used in China.This technology is a detection method based on the change of the temperature field around the space before and after pipeline leaks.It has a high accuracy in data transfer and read speed，and strong self adaptability，making it a great prospect.Before the implementation of the technology，the space temperature field before and after pipeline leaking should be studied.Using the finite volume method to build the mathematical model of the heat transfer in porous media when buried pipeline leaks.Using the FLUENT soft to numerical simulate the ground temperature change in different locations when oil pipeline leaks in winter and the law of the oil distribution in the soil.The comparison of the soil temperature field before and after the leakage show that in a certain period after the pipeline leaks，the soil temperature around the pipeline is volatile，and due to the environmental temperature，the temperature of the oil leaked first drops quickly to the freezing point，and forms different kinds of dynamic coagulation oil layers，resulting in the decreasing of the oil seepage rate，and the heat affected zone changes gradually to a stable state.In different locations of the leakage，the change of the surface temperature is big and the oil distribution in the soil is quite different.It is feasible to detect the pipeline leakage by using the distributed fiber optic temperature sensor.