梯级橡胶坝工程应急调度方案的优化设计

极端暴雨洪水给流域防洪调度带来了巨大考验,依靠单个水库独挑蓄泄重任已不能满足防洪要求,亟需探讨在突发汛情时梯级坝工程的联合应急调度方案。为此,以优化理论为指导,以梯级坝泄流时间最短为目标函数,依据坝群的运行原则,设定各库区的水位、流量等约束条件,综合考虑橡胶坝的塌落时刻及塌落速度(时长),建立梯级坝联合调度优化模型。基于梯级橡胶坝工程实例,模拟计算出坝群在不同洪水频率(1%、2%、10%)下的优化调度方案。结果表明,多变量分析模型(塌落时刻与塌落速度均为决策变量)的设计方案要比单一变量(塌落速度一定)时至少提前10 min完成泄流;在满库的情况下,研究对象中1~#—6~#级坝体自下而上最快可在75 min内完成腾容迎汛任务,且P=1%的洪水安全调度时限(从调度开始时刻到洪峰抵达工程段上游时刻所隔的时间)严格控制在90 min以内,比常规控制法缩短了至少30 min非必要的时间损耗。梯级坝联合调度优化模型可结合具体洪水量级与工程参数,科学规划各级橡胶坝的塌落方式,加快泄洪进程。尤其是当暴雨中心临近工程段上游时,相应的汇流时间短,优化模型的设计方案能确保梯级水库在较短洪水预见期内安全泄流。

Optimal design of emergency dispatching scheme for cascade rubber dams

Taking optimization theory as the guidance and the shortest discharging time of cascade dams as the objective function， the constraint conditions，i． e． water levels，flow rates，etc． of all the reservoir areas of the cascade rubber dams are set and the collapse moment and collapse speed ( duration) are comprehensively considered in accordance with the operation principle of rubber dam group，and then a joint optimized operation model for cascade rubber dams is established． Based on an actual engineering case of cascade rubber dams，the optimized operation schemes under different flood frequencies ( 1%，2%，10%) for the rubber dam group are simulatively calculated． The results show that the completion of flood discharge from the design scheme of multivariable analysis model ( with the decision variables of both the collapse moment and the collapse speed) is at least 10 min earlier than that of the single variable ( a certain collapse speed) ． Under the full-reservoir condition，the dams of 1～ 6 stages from downstream to upstream in the study object can complete the task to empty the reservoirs for flood control within a fastest time of 75 min，while the safe time limit ( the time interval between the beginning of the dispatching and the moment when the flood peak reaches the upstream section of the project) for flood dispatching at P= 1% can be strictly controlled within 90 min，from which the unnecessary time loss is at least shortened by 30 min if compared with that from the relevant conventional control methods． The joint optimized operation model for cascade rubber dams can scientifically plan the collapse modes of the rubber dams of all the stages to speed up the flood discharge in combination with the specific flood amplitude and the relevant engineering parameters． Especially，when the rainstorm center closely approaches to the upstream section of the project with a shorter flow concentration time，the design scheme of the optimized model can surly ensure the safe flood discharge with a shorter flood prediction period．