摘要
为提高管网二次加氯后消毒剂与水的混合均匀性,开发了基于螺旋流的药剂快速、低损的混合管件。通过建立混合管件的物理模型,采用Mixture多相流模型和Realizable k-ε湍流模型进行CFD数值计算,分析了混合管件的混合机理,对混合管件内导流叶不同参数下的混合效果和压力损失进行了对比研究。结果表明:水流在流经混合管件后能够改变流体的流线,使流体从一维运动变为三维运动,在管道横截面形成漩涡,促进混合效果。通过分析管道各个横截面的不均匀系数COV值可知,导流叶个数为3个时,混合效果最佳,压力损失约为157 Pa;导流叶包角为20~30°,提高包角角度能改善混合效果,但当包角度超过30°后,混合效果趋于稳定;导流叶高度在0.2~0.35倍管径时,导流叶高度越高,混合效果越好,但压力损失也随之增大。
In this study, to improve the mixing uniformity of the disinfectant in water after the secondary chlorination of the pipe network, a new type of mixing pipe fitting with high efficiency and low loss is developed. Through the establishment of physical model, the CFD numerical simulation optimization is carried out by using the mixture multiphase flow model and the realizable k-6 turbulence model. The mixing mechanism of this device is analyzed, and the mixing effect and the pressure loss under the different parameters of the guide vanes are estimated. The results show that, the streamline of the muhiphase flow can be changed after flowing through the pipe fitting, and the fluid changes from one-dimensional motion to three-dimensional motion. The mixing effect is promoted by the vortex formed in the cross-section of the pipeline. By analyzing the COV of each cross-section of the pipe, the optimum number of guide vanes for the mixing effect is 3, and its pressure loss is about 157Pa. The mixing effect is enhanced rapidly with the increase in wrap angle in the range from 20°- 30°. When the angle is more than 30°, the mixing effect tends to be stable. When the guide vane height is 0.2- 0.35 times the diameter, the higher the height of guide vanes, the better the mixing effect. Moreover, the pressure loss also increases.
出处
《中国农村水利水电》
北大核心
2017年第9期210-214,共5页
China Rural Water and Hydropower
基金
国家自然科学基金青年基金项目(51408397)
城市水资源与水环境国家重点实验室开放项目(QA201519)
太原理工大学青年基金(2013T082)
关键词
二次加氯
混合管件
混合效果
数值分析
secondary chlorination
mixing pipe fitting
mixing effect
numerical analysis
