基于雨洪高效安全利用的梯形迷宫堰优化设计方法研究

在来水规模、坝顶高程、堰宽不变且确保水库防洪标准不降低的前提下,利用迷宫堰抬高正常蓄水位,可增大蓄洪能力,提高枢纽蓄洪发电效益。在对迷宫堰的泄流能力分析的基础上,通过控制水位不变,采用非线性规划法研究堰高与侧墙夹角的关系;以保证迷宫堰正常泄流、单宫室纵向长度不大于溢洪道控制段长度和大坝安全为约束条件,以最大限度地抬高堰顶高程为目标函数,建立模型,并对模型进行优化及求解。结果表明:当控制水位不变时,在迷宫堰正常泄流范围内,堰高随着侧墙夹角的增大而减小。采用该方法对迷宫堰优化后,当坝顶高程由正常蓄水位控制时,采用迷宫堰可以降低校核水位或设计水位,提高了水库的防洪标准;当坝顶高程由校核水位或设计水位控制时,采用迷宫堰既能保证洪水安全下泄,又能大幅度提高水库的蓄洪能力。

Study on optimal design of trapezoidal labyrinth weirs for efficient and safe utilization of rain and flood

Using labyrinth weirs for operating reservoirs at higher than normal stages can expand reservoir capacity and flood storage and improve power generation efficiency, while keeping the same levels of inflow, dam height, weir height, and flood control standards. This study has adopted a nonlinear programming method to examine the relationship of weir height versus sidewall angle of labyrinth weirs at fixed reservoir stages on the basis of weir capacity analysis. We have developed and solved an optimization model, and its objective function is maximizing the weir crest elevation under the constraint of normal discharges that ensure safety and the constraint of stream-wise weir size not longer than spillway control section. The results show that to maintain normal ranges of discharge capacity at fixed reservoir stages, weir height can be reduced if sidewall angle increases. Applying this technique to optimization of weir design, we found out that if dam height is determined by normal water level, the optimized weir is able to lower check water level or design water level and hence improve flood control standard. If dam height is determined by either check water level or design water level, using such weirs can expand reservoir capacity and ensure flood discharge safety.