小石峡水电站溢洪道消能工优化试验

摘要

通过新疆维吾尔自治区库马拉克河小石峡水电站溢洪道水力学模型试验,对其原设计方案的消能工结构形式进行了优化.试验表明,消力池段在通过设计流量30年一遇洪水1 856.20 m3/s时,池内不能形成完整水跃,水跃前后波动剧烈,水流大量溢出,原设计方案的边墙高度、池长均不能满足过流要求.提出采用减小消力池池深、设置分流趾墩-消力墩-低消能坎的综合式消力池代替原设计方案的常规消力池的修改方案,在设计流量下进行泄水试验,试验结果表明,在分流趾墩、消力墩、低消能坎的联合作用下,消力池内形成强迫水跃,流态明显改善,水跃长度减小,跃后水深降低,消能率提高.采用分流趾墩-消力墩-低消能坎的综合式消力池可有效缩短消力池池长,降低边墙高度,节省工程造价,试验结果可为优化工程设计及其他同类工程优化消力池提供参考.%The structural shape of the energy dissipator in the original design scheme was optimized based on the hydraulic model tests on the spillway of Xiaoshixia Hydropower Station on Kumalake River, Xinjiang. The model tests indicated that for the original design scheme, under the design flood discharge of 1 856.20 mVs with the return period of 30 years, complete hydraulic jumps could not be formed in the plunge pool, violent fluctuations occurred before and the hydraulic jumps, and water mostly overflowed. The height of side walls and the length of the plunge pool could not satisfy the flow discharge requirements. Through many groups of model tests, the depth of the plunge pool was reduced, and conventional plunge pool in the original design scheme was replaced by the synthetic plunge pool with baffle piers, baffle blocks and low dissipation sills. Model tests on the spillway were carried out under the design discharge of 1 856.20 nrVs. The test results show that under the combined action of baffle piers, baffle blocks and low dissipation sills, forced hydraulic jumps have formed, and the flow pattern is obviously improved. Meanwhile, the length of the hydraulic jumps decreases and their second conjugate depth also decreases. The rate of energy dissipation has increased. To this end, under the premise of ensuring the rate of energy dissipation, the synthetic plunge pool with baffle piers, baffle blocks and low dissipation sills can effectively reduce the length of the plunge pool and the height of its side walls and to save the construction cost. The test results can be referred by the design of optimization projects and the optimization of plunge pools for other similar projects.