机构地区:[1]中国农业大学北京市供水管网系统安全与节能工程技术研究中心,北京100083 [2]中水北方勘测设计研究有限责任公司,天津300222 [3]深圳市东江水源工程管理处,深圳518036
出 处:《农业工程学报》2015年第16期71-77,共7页Transactions of the Chinese Society of Agricultural Engineering
基 金:国家自然科学基金项目(51139007);国家科技支撑计划项目(2015BAD20B01)
摘 要:大型泵站前池和进水池经常存在表面旋涡和附壁涡,从而影响水泵运行稳定性。而由于大型泵站的尺度大,单一型式的导流墩很难改善这类泵站的进水流场。该文以广东省永湖泵站为研究对象,采用数值计算和现场测试相结合的方法,研究了组合式导流墩在改善大型泵站前池、进水池流态方面的效果,构建了由八字型导流墩、川字型导流墩和十字型消涡板相结合的组合式导流墩。三维流体动力学计算发现,组合式导流墩利用前端的八字型导流墩降低前池扩散角,减弱前池大尺度表面旋涡,借助后续的川字型导流墩调整流动均匀度,将水流均匀导入进水池,再通过水泵吸水喇叭管下部的十字型消涡板去除水泵吸水喇叭管周边的附底涡,提高流速分布均匀度,经计算喇叭管底面、水泵进口断面流速分布均匀度分别提高了7.8%、10.6%。实际测试表明,组合式导流墩将水泵最大压力脉动降低17.1%,将水泵振动由D区降低到C区,达到水泵技术标准规定的振动要求,保证了泵站的安全稳定运行。该研究对大型泵站建设提供了参考。Surface vortex and submerged vortex originating from intake wall often exist in fore-bay and sump in a large-scale pumping station. These vortices may affect the stability of pump operation. Because of big dimension, single diversion pier cannot effectively improve the intake flow field in large-scale pumping station. The Yonghu pumping station, a large-scale pumping station, which was located in Guangdong Province, was taken as the research object. The numerical simulation and the site test were performed in order to investigate the effects of combined diversion piers on rectifying intake flow pattern in fore-bay and sump. A new type of combined diversion pier composed of double-I type, three-I type and cross vortex baffle were proposed. The flow pattern, the vorticity and the uniformity of axial velocity distribution were compared between the original design and the optimized design. The numerical simulation results showed that the new type of combined diversion pier could effectively improve the intake flow field of the pumping station. For the original design, 2 large-size circulations in the fore-bay and submerged vortices in the sump were observed. The size and strength of vortices increased with the increase of the water depth. Furthermore, spiral vortices existed in the 2 sides of the sump. However, for the optimized design, the double-I type diversion piers in front reduced divergent angle of the fore-bay, and decreased the size and strength of surface vortex. The three-I type piers adjusted the uniformity of flow field, and water flow was well introduced to the corresponding pump sump. Submerged vortices originating from bottom wall were almost completely eliminated by the cross vortex baffle. Flow pattern was uniform and smooth in the inlet of pumps, and the streamlines of axial section of pumps were good, without vortices. The uniformity of axial velocity distribution of pump inlet section was as high as 91.42%, and the axial velocity angle approached 86.01 °. Compared to the original design, the uni
分 类 号:TV675[水利工程—水利水电工程]
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