基于空腔流动理论的市政消火栓盲端铁迁移扩散机理研究

Research on mechanism of iron migration and diffusion from dead⁃end branch pipe of municipal fire hydrant based on square cavity flow mechanism

市政消火栓滞水严重,存在积累扩散亚铁离子(Fe^2+)的问题,可能引发“红水”现象,威胁供水卫生安全.以往的管网水质模拟缺少对消火栓盲端支管的研究,难以准确模拟消火栓铁释放现象,使得计算精确度不足.针对上述问题,本研究尝试运用空腔流动机理分析市政消火栓构成的盲端支管内Fe^2+迁移扩散现象,结合扩散实验和数值模拟,构建盲端支管Fe^2+扩散的流体力学模型,定量分析管长、管径、流速等因素的影响规律,为精确模拟消火栓水质提供参考.

Municipal fire hydrants release ferrous ions into the internal water,which may cause“red water”phenomenon and damage to water supply safety.However,few previous studies aim at the water quality simulation of dead⁃end branch pipe of fire hydrant,so it is difficult to accurately simulate the fire hydrant iron release phenomenon,which reduces the accuracy of calculation.Aiming at these problems,this study applies square cavity flow mechanism to analysis the problem of iron release from municipal fire hydrant dead⁃end branch pipe.Meanwhile,this study uses the experiment and numerical simulation to establish the dead⁃end branch pipe ferrous ion diffusion of computational fluid dynamics model,so as to realize quantitative analysis of the law of the influence of such factors as length,diameter,flow velocity,provide a reference for accurate simulation of fire hydrant water quality.