海底熱油管道温度场模拟.docx

摘要海上油气田开采的油气大部分将通过管道运输至陆上进行再处理。海上原油管输过程中，需要加热来降低原油的粘度。控制合适的输油温度、管道稳定安全运行等需要准确确定海底输油管道在不同季节、不同地域等条件下的温度场分布情况。此外，管输作业中，不可避免的遭遇自然灾害、管道维修等紧急情况，原油被迫停输；在停输阶段，管内原油温度降低，粘度上升，当油温降至某温度时，会给管道的再启动带来极大困难，甚至于造成凝管事故，为避免此类情况发生，需要准确预测停输温降规律和安全停输时间。本文对海底输油管道的稳态及非稳态传热问题了进行了数值模拟。主要进行了以下几方面的工作：1、分析了输油管道在运行过程中的传热特点，将海底输油管道的热作用区域简化为矩形区域，并建立了海底输油管道的物理模型和数学模型。2、对海底输油管道稳定运行时周围砂土温度场进行了模拟计算，计算出了管内原油的沿程温降，绘制了原油沿程温降曲线图。3、建立了海底输油管道停输阶段的物理数学模型，并对微分方程进行了数值求解，模拟计算了各工况条件下的安全停输时间，绘制了停输时原油温降曲线。本文对海底输油管道传热问题求解的尝试，所建立的海底输油管道的物理模型和数学模型，所应用的数值计算方法，为进一步研究海底输油管道的传热机理提供了理论参考；求解结果为海底输油管道的稳定安全运行提供了技术支持。关键词：海底输油管道；安全停输时间；温度场；数值模拟AbstractExploitation of marine oil and gas resources is the major orientation of Chinas energy development. Pipelines will transport most of the oil and gas from offshore oil fields to mainland. In the transportation process of crude oil, heating up is needed to reduce the viscidity of the crude oil. The temperature field, under different surroundings and terrains, is needed to accurately know for lowering the oil temperature. Otherwise, nature disaster and pipeline maintains are inevitable, which compel the crude oil to shutdown.In addition, the unavoidable natural disasters and emergencies such as pipeline maintenance will force the Shutting down of crude oil; During the shutdown, the temperature of crude oil depresses and the viscidity rises, when it drops to a certain temperature, the restarting of pipeline will be very difficult, even cause to coagulate pipe; in order to avoid such incidents , the temperature drop law and shutdown time is needed to accurately predict.In this paper, the numerical solution is used to solve the steady and non steady heat transfer of submarine oil pipeline, and the corresponding program codes are instituted. The main work is as the following:1. Analysis of the oil pipeline to the heat transfer characteristics, the thermal effect area is simplified to rectangle region, based on which the physical and mathematic models are established.2. The stable temper