原油凝管电加热解凝模拟计算研究

Research on Simulation Calculation of Electrical Heating Unblocking of Crude Oil Pipeline Blockage

针对原油凝管电加热解凝问题,借助CFD仿真软件建立凝油融化传热相变数学模型。模拟计算结果表明:解凝前期,凝油是由外层向内层逐渐融化,靠近管道顶部区域融化速度较快。解凝后期,悬浮状态的凝油逐渐被四周高温液相热油包围,热对流作用加强,凝油融化速率加快;通过对管道加载不同温度对比解凝效率分析得知,原油黏度变化是影响解凝效率的重要因素,将黏度随温度升高而降低时出现拐点的温度作为管道加载温度,解凝效率最高;并且通过给不同管道加载相同温度情况下对比解凝速率得知,管径越小管壁热源向凝油区热量传递效率越高,热损耗较小,解凝速率越大,反之管径越大解凝速率越小。

Aiming at the problem of electrical heating unblocking of crude oil pipeline blockage, the phase transition mathematical model of the solidified oil melting question was established with the help of CFD simulation software. The simulation calculation results showed that,in the early stage of unblocking, the solidified oil gradually melted from the outer layer to the inner layer, and the area near the top of the pipeline melted faster. In the later stage of unblocking, the suspended solidified oil was gradually surrounded by the surrounding high-temperature liquid phase hot oil, the effect of heat convection was strengthened, and the melting rate of solidified oil was accelerated. Through the analysis and comparison of the unblocking effect by loading different temperatures on the pipeline, it was known that the viscosity change of the crude oil was an important factor affecting the unblocking effect. The temperature at which the inflection point occurred when the viscosity decreased with increasing temperature was used as the pipeline loading temperature, and the unblocking effect was the highest. And by comparing the unblocking rate under the condition of loading different pipes at the same temperature, it was known that the smaller the pipe diameter, the higher the heat transfer efficiency of the pipe wall heat source to the condensing zone, the smaller the heat loss, the greater the unblocking rate. On the contrary, the larger the pipe diameter, the lower the unblocking rate.