Abstract:

The Euler-Euler multi-fluid model has been widely used to simulate numerically the separation performance of oil-water mixture inside the T junction, while no study has been conducted on the oil droplet size distribution and its influence on separation performance. The CFD-PBM numerical simulation of oil-water mixture flow inside a specific T junction was carried out, and experiments were conducted in laboratory to verify the accuracy of the simulation results. It is indicated that the oil droplet size in the T junction appears a gradually increasing trend along the flow direction. With the increase of oil droplet size, the oil-water separation efficiency can be effectively promoted. On the contrary, the smaller oil droplet size leads to the difficulty of oil-water separation inside the T junction, and the fraction of phase distribution is nearly identical to the split ratio. The influence degree of operation conditions such as split ratio and Reynolds number on the separation efficiency is tightly related to the oil droplet size. Appropriate operating conditions should be selected carefully to achieve high separation efficiency for the T junction.

Key words: T junction, numerical simulation, computational fluid dynamics, population balance model, separation efficiency, size distribution

摘要：

目前关于T型管内油水分离特性的数值模拟大多采用Euler-Euler多相流模型，考虑管内油滴粒径分布及其对油水分离特性影响的研究工作尚未见报道。对T型管内的油水两相流动情况和分离特性进行了CFD-PBM数值模拟，并进行了室内实验以验证模拟结果的准确性。结果表明，T型管内油滴粒径随流体流动方向具有逐渐增大的趋势；增大来液中的油滴粒径分布可以有效提高油水分离效率，反之当来液中的油滴粒径较小时，油水两相在T型管内不易分离，相分配比始终与分流比几乎相同；分流比、Reynolds数等操作条件对油水分离效率的影响程度与油滴粒径密切相关，应慎重选取适当的操作条件以保证T型管的油水分离效率。

关键词: T型管, 数值模拟, 计算流体力学, 相群平衡模型, 分离效率, 粒度分布