突扩廊道体型减免高水头船闸输水阀门空化研究

高水头船闸存在的主要关键技术问题是船闸输水阀门的空化与空蚀问题.本文在综合研究国内外改善输水阀门空化的措施基础上,提出了突扩廊道体型以及减免输水阀门空化,通过物理模型试验和原型观测研究,充分论证了突扩廊道体型减免空化的效果.结合三峡工程连续五级船闸水力学试验研究,优化了突扩廊道体型,提出了结构简单、具有很强抗空化能力的底扩体型.闽江沙溪口船闸水力学原型观测成果表明,突扩廊道体型减弱了阀门空化强度,起到了保护阀门和廊道边壁免遭空蚀破坏的作用,保证了该船闸的正常运转.

Study on Preventing and Reducing Cavitation of Filling Valves for High Head Shiplocks

At present,cavitation and induced erosion in the filling valves has become a key problem of the high head locks. On the basis of comprehensive studies on cavitation in the filling valves at home and abroad, this paper mainly presents measures in prevention of cavitation in the filling valves by use of various sudden culvert expansion,and fully demonstrates their effects on preventing and reducing cavitation via physical model, mathe-matic model and prototype observation. Based on studies on hydraulics in the Three-Gorges five-step locks,the sudden culvert expansion has been optimized and a sudden bottom expansion which has higher resistance cavitation and simple structure has been developed. Such expansion has a lot of characteristics of improvement of flow structure in the culvert behind the filling valves, reduction of pressure fluctuation of flow and increase of pressure behind the valves to a certain degree. Some result of prototype observation on lock hydraulics in Shaxikou Project located on Mingjiang River shown that the sudden culvert expansion has reduced cavitation intensity in the valves,prevented the valves and culvert walls from cavitation damage and kept the lock in good condition.