基于CFD的原油储罐导热油加热过程数值模拟研究

CFD Based Simulation of Heating Process by Heat Conduction Oil in Oil Storage Tank

原油储罐内油层温度和固液相态分布对储罐利用效率及安全运行具有重要意义。本文基于实际工程背景,利用商业软件ANSYS/FLUENT对高温导热油在储罐中心附近加热原油进行了数值模拟研究。数值结果表明,在室外环境温度为-30℃的条件下,当原油存储时间为第六天时约有16.5%的原油发生凝固,且凝固主要集中在罐底和罐壁附近。研究同时发现,罐底和罐壁处呈现明显的热分层现象,且罐底附近的温度梯度较大。其主要原因为,罐壁外侧覆盖100mm厚的岩棉保温层而罐底直接与混凝土基础接触,且混凝土基础温度与环境温度接近(-30℃),导致罐底附近传热温差较大。研究结果可为新疆某油田原油储罐加热方式改造项目提供一定的理论指导。

The distribution of temperature and solid-liquid state of crude oil in storage tank is of great significance to the utilization efficiency and safe operation for storage tank.Based on the actual engineering background,the numerical simulation of heating process by conduction oil in the pipe near the center of storage tank by ANSYS/FLUENT was carried out in this paper.The result shows that about 16.5%of the crude oil in tank has been solidifiedby the sixth dayand solidification mainly occurs near the bottom and wall of the tank.It is also found that there exists obvious thermal stratification near the bottom and the wall of the tank,furthermore,the temperature gradient near the bottom of the tank is larger than that of the wall.The main reason is that there is 100mm thick rock wool insulation layer on the tank wall,while the bottom of the tank is in direct contact with the concrete foundation.The temperature of concrete foundation is close to the ambient temperature(-30℃),which results in higher heat transfer temperature difference near the bottom than that of the wall of the tank.The simulation results could provide a theoretical guidance for heating modification project of the oil storage tank in Xinjiang oil field.