多级孔板扰流泡沫发生器流场模拟分析

Numerical Study of Gas-liquid Flow in Foam Generator with Disturbing Device of Multi-orifice

通过数值模拟方法,对内锥和多级孔板组合扰流结构下的泡沫发生器流场进行了模拟和分析。通过CFD流场模拟软件Fluent,以泡沫发生器的真实操作工况为边界条件进行建模,得到了气液两相掺混流场的结构和重要动力学参数,并进行了分析。发现扰流件的下游区域存在一个较稳定回流区,同时在多级孔板区域流场的湍动能及湍动能耗散率较高,对泡沫发生器中气液两相掺混有利。扰流件下游液相分布较为均匀,进一步验证了发泡器内部气液掺混效果较佳。通过流场模拟,验证了圆锥和四级孔板组合扰流结构对强化泡沫发生器内气液掺混的有效性。

In order to study the performance of foam generator with disturbing device in form of multi - orifice for gas and liquid mixing which is used in the large flow rate fire extinguishing device, the two phase flow field under the composed disturbing device of V cone and multi -orifice was got and analyzed. The numerical model was build on the real operating conditions of foam generator by CFD software Fluent, and the two phase flow structure with some flow dy- namic parameters was studied, such as velocity, pressure, turbulent energy and liquid phase distribution in the flow field, etc. There was a strong counter - flow domain downstream the disturbing device, and the turbulent energy and turbulent dissociation rate around the multi - orifice were higher than other domains, which is beneficial to the two phase flow mixing. Also, the homogeneous liquid phase distribution showed a well gas and liquid mixing effect in the foam generator. All these afore mentioned factors contributed to the mixing efficiency of the two phase flow in the foam generator. Through the flow field simulation, verify the effectiveness of the cone and four hole plate combination structure of gas - liquid mixed flow perturbation in the mixed enhanced foam generator.