摘 要：
为了充分了解灌溉用砂石过滤器和筛网过滤器组成的二级过滤系统的内部流场情况,利用Pro/Engineer软件进行三维造型,基于计算流体动力学(Computational fluid dynamics,CFD)技术,应用数值模拟采用RNG k-ε湍流模型结合多孔介质模型对过滤器内部流场进行分析并提出优化方案,在优化的基础上设计新型一体式过滤器并对其进行性能测试。结果表明:RNG k-ε湍流模型模拟结果与试验结果吻合良好,可用于流场分析和结构优化。组合过滤系统按传统分体式布置时,由于连接管道和筛网过滤器外壳等影响,会产生较大水头损失,且筛网过滤器部分由于结构复杂造成环流与漩涡,导致流场不稳,过滤时流速分布不均。针对传统组合过滤系统流场的不足,提出将滤网融入砂石罐体的一体式优化布置方案,改善了布置的复杂度;通过流场分析发现可减小38.5%的水头损失,且由于罐体空间较大对水流扰动较小,所以内部流场稳定;过滤时流速分布更均匀,因此对滤网的利用也更加合理充分,延长了滤网使用寿命。通过两次性能测试对比分析可知,砂石-筛网组合一体式过滤器能有效减小水头损失,并且在含沙水条件下流量减小20%时能多运行20 min左右,表明一体式过滤器水力性能更优且能提高灌溉效率。
译 名：
Structural Optimization and Performance Test of Sand-Screen Combination Filter
作 者：
YANG Peiling;ZHOU Yang;REN Shumei;MA Zixuan;College of Water Resources and Civil Engineering,China Agricultural University;
单 位：
YANG Peiling%ZHOU Yang%REN Shumei%MA Zixuan%College of Water Resources and Civil Engineering,China Agricultural University
关键词：
filter;;porous media;;numerical simulation;;structural optimization
摘 要：
In order to get fully understanding of the interior flow field of a two-stage filtration system composed of sand filter and screen filter in irrigation system,the interior flow field was analyzed and offered optimization by building 3 D model using Pro/Engineer,based on computational fluid dynamics(CFD) technique,numerical simulation and using RNG k-ε model combined with porous media model.And the new integrated filter was made and the performance test it was done. As it was shown in the result,simulation results of the RNG k-ε model were consistent with the experimental results. Therefore,the model can be used for flow field analysis and structural optimization. When the combined filter system was set with sand filtration material and screen mesh separately installed in different shells,it would cause huge water head loss due to the influence of pipes between sand filter and screen filter and shell of screen filter. And too much circulation and whirlpool of water inside the filter due to complexity of structure led to instability of flow field,which finally caused uneven distribution of velocity during filtering. In terms of the shortcoming of traditional combination filter system based on field flow analysis,a new type of integrated layout optimization incorporating the screen into the sand filter was proposed to improve the complexity of the layout. According to the field flow analysis,integrated filter's water head loss was decreased by 38. 5%,and interior field flow was more stable because the tank space was larger and the flow disturbance was smaller. And the flow velocity distribution was more uniform during filtering,so the utilization of the screen was more reasonable,and the screen life of the filter was extended. After the comparison of two performance tests,it was known that the new integrated filter can effectively reduce the loss of water head and it can run about 20 min more when the flow rate was decreased by 20% under the condition of sand water. It was showed that the new integrated filter'shydraulic performance was better and the irrigation efficiency was improved. According to the research raised above,a kind of digital method was proposed to discuss the performance of the filter,which was used to research and design a kind of integrated filter,and finally the advantageous structure of the integrated filter was obtained,including the sand filter and the screen filter.
