煤矿瓦斯旋流混合器定工况下混合均匀性研究

利用简化的数学模型对给定工况下煤矿瓦斯旋流混合器的混合均匀性进行了研究,主要研究旋流方式和旋流强度对乏风瓦斯出口速度和体积分数分布均匀性的影响. 研究结果表明:在外管气体的流量和转动惯量明显大于内管的工况下,外管的旋流对出口的速度场起到主导作用,使出口乏风瓦斯的速度分布均匀性降低;内管的旋流建立了径向和轴向的反压力梯度,产生了中心回流区,增强了内、外管流体动量和质量的交换,使出口的体积分数分布均匀性明显提高;随着旋流强度的提高,外管具有旋流的旋流方式的出口速度分布均匀性变差,而内管具有旋流的旋流方式的回流区掺混强度增大,有利于乏风瓦斯体积分数混合均匀性的提高. 

Research on the Mixing Uniformity of Coal Mine Methane Swirl Mixer Under Given Inlet Condition

The mixing uniformity of coal mine methane swirl mixer was numerically investigated under given inlet condition focusing upon the effects of swirl way and swirl intensity on the outlet uniformity of velocity and concentration distributions. The results show that, on condition that the flow mass and moment of inertia of outer tube gas are greater than that of inner tube, the swirl flow of outer tube gas dominates the velocity field at outlet and decrease the outlet velocity distribution uniformity. The swirl flow of inner tube gas sets up the reverse pressure gradient in radial and axial direction that leads to the creation of return flow region, which enhances the momentum and mass exchange of inner and outer tube gases and significantly improve outlet concentration distribution uniformity. With the increase of swirl intensity, the outlet velocity distribution uniformity decreases for swirl ways with outer tube gas swirling, while the mixing intensity strengthens in return flow region which contributes to the improvement of concentration uniformity for swirl ways with inner tube gas swirling.