含蜡原油管道停输降温的数值计算

Numerical Calculation of the Temperature Drop of the Waxy Crude Oil Pipeline

埋地热含蜡原油管道停输后,当管内原油温度降至析蜡点以下时,原油中的蜡晶将逐渐析出。根据含蜡原油降温过程中黏弹性随温度的变化特点,利用温降过程中储能模量、损耗模量和损耗角的变化与温度的关系提出了划分管道停输温降阶段的方法,即以析蜡点和储能模量与损耗模量相等时(损耗角等于45°)的温度点为临界点,将温降过程划分为三个阶段,并以花格管道为例利用FLUENT软件对原油降温过程进行数学描述和计算求解。另外还选取不同性质的原油对该方法进行验证,得到含蜡原油管道停输温降规律。

After the shutdown of the waxy crude oil pipeline,the wax-crystals in the crude oil will gradually separate out when the temperature in the pipe falls below the wax precipitation point.According to the variation of viscoelasticity of waxy crude oil with temperature in temperature drop process,a method for dividing the temperature -drop stage during the shutdown of pipeline was put forward by using the relation of the storage modulus,loss modulus and loss angle with temperature.The temperature drop process was divided into three stages with the critical point of wax precipitation point and the temperature point when the storage modulus and loss modulus were equal (loss angle equaled 45 degrees).Taking the Huage pipeline as an example,FLUENT was used to describe the temperature drop process and calculate the solution.In addition,crude oil with different properties was selected to verify the method,and the rule of temperature drop in waxy crude oil pipeline was obtained.