新型超音速旋流分离器流场分析与性能评估

Flow field analysis and performance evaluation on new supersonic swirling separator

为了解决实际开采过程中高压天然气的含水问题,结合气体动力学和流体热力学原理,设计了一套前置式超音速旋流脱水装置,围绕新装置进行了流场模拟和性能分析两方面研究。首先根据几何尺寸建立了三维数值计算模型,并结合RNG k-ε湍流模型对超音速分离器内部流场进行了模拟,得出了装置轴心线上天然气压力、温度、马赫数等特性参数的分布规律,同时对不同截面上参数的径向变化进行了分析;最后根据露点降和分离效率评估了超音速旋流分离器的工作性能,结果表明:在喷管出口处马赫数为1.51,膨胀最低温度可达140K,切向旋流速度为160m/s,可以实现水蒸气的充分凝结和分离;当压损比达到70%时,可以得到32℃的露点降,而且装置对于变压力、变温度工况具有很好的适应性,完全可以满足生产实际要求。

To solve the problem of the high-pressure natural gas containing water vapor in real oil production,a type of front-placed supersonic dehydration device was designed according to gas field condition and gas well drilling technology parameters. Both numerical simulation and performance study were carried out for the new device. Based on the physical dimension,a three-dimensional CFD model was established,and the RNG k-ε turbulence model was selected to simulate the internal flow field of the supersonic separator. The separation parameters such as pressure,temperature,velocity and Mach number along the axis inside the supersonic separator were investigated. The flow characteristics along the radial direction in different sections were also discussed. In addition,the performance of the device was also carried out to validate the numerical model. The results showed that the Mach number could reach 1.51 at a low temperature of 140 K and the tangential velocity was 160m/s,which can realize fully water vapor condensation and separation. When pressure loss ratio was 70%,the dehydration of dry gas could be up to 32℃. At the same time,the new device accommodating to variable pressures and temperatures completely meets the requirements of actual production.