高水头、小底坡泄洪中孔掺气坎体形优化与运行实践  

Shape Optimization and Operation Practice of Middle Hole Aerators for Flood Discharge with High Head and Small Bottom Slope

作　　者：罗永钦 谌东升 翟秉星 杨红宣[1] LUO Yongqin;CHEN Dongsheng;ZHAI Bingxing;YANG Hongxuan(Kunming University of Science and Technology,Kunming 650500,Yunnan,China;Datang Guanyinyan Hydropower Development Co.,Ltd.,Kunming 650033,Yunnan,China)

机构地区：[1]昆明理工大学,云南昆明650500 [2]大唐观音岩水电开发有限公司,云南昆明650033

出　　处：《水力发电》2022年第12期98-102,共5页Water Power

基　　金：中国华能集团有限公司科技项目(HNKJ21-HF240);云南省国际河流与跨境生态安全重点实验室开发基金(KKZ62021040-05);昆明理工大学人才培养项目(KKZ3202004052)。

摘　　要：高水头、小底坡、水位变幅大的掺气设施体形优化难度大。某水电站泄洪中孔最大水头达92.37 m,底坡仅5.0%,运行水位变幅为11.37 m,掺气坎体形是设计难点。基于1∶40的单体水工模型试验,对掺气坎的体形进行了系列优化,获得最终推荐体形。研究表明:采用“坎下局部变坡+小挑坎+掺气槽”的设计,能满足高水头、小底坡、水位变幅大的泄槽掺气要求,各道掺气坎均能形成稳定空腔,掺气效果较好;掺气挑坎的细节尺寸对掺气效果极为敏感;建议建立掺气空腔与其影响因子的数学分析模型,以获得掺气坎优化体形的最佳解。该工程目前已运行近7年,总体效果良好,但突扩突跌后的侧墙发生了局部空蚀,表明对高水头泄水建筑物,宜同时采用减压模型全面、充分论证其局部空化特性。It is difficult to optimize the shape of aeration facilities with high water head,small bottom slope and large water level variation.As the maximum head of the middle hole of spillway in a hydropower station is 92.37 m,the bottom slope is only 5.0%and the amplitude of operating water level variation is 11.37 m,the aerator shape is the design difficulty.Based on the 1∶40 single hydraulic model test,the shape of aerator is optimized in series,and the final recommended shape is obtained.The research shows that,(a)the design of“Local slope change under the bank+small flip bucket+aeration tank”can meet the aeration requirements of the discharge tank with high water head,small bottom slope and large water level variation,and each aeration tank can form a stable cavity with good aeration effect;(b)the detail size of aerating bucket is very sensitive to the aerating effect;and(c)it is suggested to establish the mathematical analysis model of the aeration cavity and its influencing factors in order to obtain the best solution of the optimized shape of aerator.The project has been operated for nearly 7 years and the overall effect is good,but local cavitation has occurred on the side wall after sudden expansion and sudden fall,indicating that for high head discharge structures,the decompression model should be used to comprehensively and fully demonstrate their local cavitation characteristics.

关 键 词：高水头 小底坡 水位变幅大 双泄中孔 掺气坎 体形优化 

分 类 号：TV135.2[水利工程—水力学及河流动力学]