明渠调水工程流量切换条件下的渠池水力响应特性分析

An Analysis of Hydraulic Response Characteristics of Canal Basin under Flow Switching Conditions in the Nullah Water Transfer Project

大型跨流域明渠调水工程中各类输水元件相互连接,其过流特性各异,且在输水过程中各元件相互扰动,导致沿线水情复杂多变,开展渠池水力响应特性分析对维持工程安全平稳运行具有重要意义。通过构建一维水动力模型,以安全调控为导向,分析安全调控时间可行域。即为避免水位超限现象的发生,计算调控后不超渠池水位上下限的建筑物最早调控时间与最晚调控时间,并以引江济淮工程派河口泵站上下游渠池为例开展实例研究。研究过程中,因渠段选取原因,最早调控时间为0h,故对最晚调控时间进行分析。结果表明:①当上游初始流量与下游水位保持不变时,最晚调控时间随目标流量、流量变化量增大而呈幂函数关系递减;②上游初始流量相同流量变化量不同时,最晚调控时间随下游水位增大而逐渐减小,且流量变化量越大最晚调控时间减小趋势越平缓;③最晚调控时间与流量变化量的相关性最强,与上游初始流量相关性较差。最后基于安全调控时间可行域计算结果,构建了最晚调控时间快速生成公式。

In large-scale inter-basin open channel water transfer projects,all kinds of water conveyance elements are connected with each other,and their flow characteristics are different,an analysis of the hydraulic response characteristics of the ditch basin is of great significance for the safe and stable operation of the project.By constructing one-dimensional hydrodynamic model and taking safety regulation as guidance,the feasible time domain of safety regulation is analyzed.In order to avoid the occurrence of water level exceeding the limit,the earliest and the latest regulating time of the buildings that do not exceed the upper and lower limits of the water level of the canal pool are cal-culated,taking the upper and lower reaches of the pumping station in the river mouth of the Yangtze-Huaihe River Diversion Project as an example,the study is carried out.During the study,due to the selection of channel segment,the earliest regulation time was 0 h,so the lat-est regulation time is analyzed.The results show that:①when the initial upstream flow and downstream water level remain unchanged,the latest regulation time decreases with the increase in the target flow and flow variation in a power function relationship②When the initial up-stream flow is the same and the flow variation is different,the latest regulation time gradually decreases with the increase in the downstream water level,and the decrease trend of the latest regulation time becomes gentler with the increase in flow variation;③The latest regulation time has the strongest correlation with the flow variation,but has a poor correlation with the upstream initial flow.Finally,based on the calcu-lation results of feasible region of safety regulation time,a fast generation formula of the latest regulation time is constructed.