Abstract: The height of the separation interface in the gravity oil-water separator determines the volume ratio of the oil and water phases, which affects the height of the oil and water phases floating up or settling down in the separator, and has a direct impact on the separation effect. In order to investigate the influence of the height of separation interface on the separation effect of the gravity oil-water separator, numerical simulation is carried out using Fluent software to investigate the separation effect under different inlet flow rates and different water phase outlet flow ratios. The results show that the height of separation interface decreases with the increase of water phase export flow rate, and the lower the oil content in the inlet, the faster the height of separation interface decreases. As the height of separation interface decreases the oil content in the oil phase export gradually increases, and the separation effect is the best when the separation interface is in the vicinity of the axis of the separator, and the oil content of oil phase export can be up to 97%~98% under different inlet flow rates. As the height of separation interface decreases, the high-speed region behind the rectifier plate of the separator gradually moves down and the velocity gradient gradually decreases, which improves the velocity uniformity within the polystructure and reduces the influence of the radial velocity on the oil phase export, and thus improves the separation effect.

Key words: gravity oil-water separator, separation interface, inlet flow rate, oil content at oil phase outlet, water phase outlet flow ratio

摘要： 重力式油水分离器内分界面高度决定了油水两相的体积占比，影响分离器内油水两相的上浮或沉降的高度，对分离效果具有直接影响。为探究分界面高度对重力式油水分离器分离效果的影响，采用Fluent软件对不同进口流速、不同水相出口流量占比下的分离效果进行了数值模拟研究。结果表明，分界面高度随水相出口流量占比增加而降低，入口含油率越低，分界面高度降低速度越快；随着分界面高度降低油相出口含油率逐渐增加，当分界面处于分离器轴线附近时分离效果最佳，不同入口流速下油相出口含油率可达97%~98%；随着分界面高度降低，分离器整流板后方的高速区域逐渐下移且速度梯度逐渐减小，提高了聚结构件内的速度均匀度，降低了径向速度对油相出口的影响，进而提高了分离效果。

关键词: 重力油水分离器, 分界面, 入口流速, 油相出口含油率, 水相出口占比