兼有深水孔的旋流喇叭形竖井泄洪洞设计原理

Design principles of the swirling device of morning glory shaft spillway with a deep intake

基于旋流防蚀、消能、避免产生雾化和保护生态环境的理念,研究一种在高水头旋流喇叭形竖井下设置深水孔的新型泄水结构物,其特点是泄洪和放空水库(或排沙和引水)共用同一个竖井和导流洞,结构简洁、运行安全和经济。文中系统地介绍了旋流喇叭形竖井及深孔引水道同涡井连接结构的设计原理,并给出深孔不参与和参与泄洪时的工程案例设计。本文通过以往的研究成果优化组合,创造出带有双层进水口的一条泄洪洞,用以取代传统的两条泄洪洞,故可以节省大量工程投资。由于喇叭形进水口及深层引水道都有起旋设施,使竖井产生空腔通气的旋转流运动,可以消减井、洞内的负压,防止结构物空蚀和提高消能率,因此,出口流速低,可以避免发生雾化现象。故本研究成果具有学术价值和广泛的应用前景。

Based on the ideas of swirling flow cavitation mitigation, energy dissipation, atomization prevention and environment protection, a new flood discharge structure which composed of a swirling device of morning glory shaft spillway and a deep intake has been developed. Its remarkable characteristics are that the flood release as well as desihing or water transport to downstream for emptying the reservoir share the same shaft and diversion tunnel. Thus it has a simple structure and is more reliable and economic. The design principles and samples of such structure are systematically presented, including the deep intake has been involved in flood discharge or not. In this paper, a double-inlet spillway tunnel is created by optimizing the previous project to substitute the traditional scheme with two spillways. As a result, a lot of investment is saved. Because the swirling device is designed in both the trumpet-shaped inlet and a deep intake, a swirling flow with the air core and the annular jet central ventilation occurs in the shaft spillway to mitigate the negative pressure in the shaft and the spillway and prevent from cavitation, improving the energy dissipation efficiency and avoiding the atomization.