闸前溢流井在长距离调水隧洞中的水锤防护特性研究

发布时间：2018-06-29 02:30

本文选题：调水系统 + 闸前溢流井　；参考：《浙江大学》2017年硕士论文

【摘要】：在有压管路中,由于阀门突然关闭、水泵机组突然停车等原因使水流速度发生突变,从而引起压强急剧升高和降低的交替变化,这种变化以一定速度向上游或下游传播,并且在边界上发生反射,这种水力现象称为水锤。水锤可导致管道系统强烈震动产生噪声,可能破坏管道、水泵、阀门设施,并引起水泵反转,管网压力降低等不利现象,在长距离调水系统中水锤的危害尤甚。在长距离调水系统中,闸前设置溢流井可以有效控制长距离输水系统在启闭过程中的水锤压力波动。为了分析闸前溢流井在长距离调水隧洞中水锤防护的特性,并对闸前溢流井的体型和参数进行优化设计,本文采用理论分析与数值模拟相结合的方法,建立了包含闸前溢流井的长距离调水系统的水锤计算模型。通过数值建模和编程计算,对长距离输水隧洞中采用通气孔和闸前溢流井联合控制水锤的特性进行了模拟,获得了不同运行情况下通气孔和闸前溢流井的非恒定涌浪过程,全线极值压力分布。比较了有无设置闸前溢流井时,沿程通气孔的涌浪特性和全线极值压力分布,分析了闸前溢流井对长距离调水系统的水锤防护作用。为了优化闸前溢流井的设计,对溢流井高度、糙率系数、闸前溢流井的平面位置、输水管道的内径、溢流井的截面积等进行了敏感性分析,分析了各个参数对全线极值压力分布、溢流流量和溢流持续时间的影响。本文的研究结果表明,通过设置闸前溢流井,可以良好控制通气孔的涌浪高度和全线的水锤极值压力。溢流井的高度和输水管道内径是影响全线极值压力分布最主要因素。在一定范围内,降低溢流井的高度,全线极值压力相应减小,但溢流井的溢流流量和历时会增加;增加输水管道内径,可以减小全线极值压力,同时也可以减小溢流井的溢流流量和历时。在长距离隧洞输水系统中,可以通过增加输水管道内径和减小溢流井的高度来控制全线极值压力的分布,调节溢流井的溢流过程。
[Abstract]:In a pressurized pipeline, the sudden closure of the valve and the sudden shutdown of the pump unit cause sudden changes in the velocity of the flow of water, resulting in a sharp rise and decrease in the pressure, which propagates at a certain speed upstream or downstream. And reflection occurs at the boundary, a hydraulic phenomenon called a water hammer. Water hammer can lead to strong vibration of pipeline system produce noise, may destroy pipeline, water pump, valve facilities, and cause adverse phenomena such as reverse of water pump, reduction of pipe network pressure, etc. The harm of water hammer is especially serious in long distance water transfer system. In the long distance water transfer system, the water hammer pressure fluctuation in the long distance water conveyance system can be effectively controlled by setting an overflow well in front of the sluice. In order to analyze the characteristics of water hammer protection in long distance diversion tunnel, and to optimize the shape and parameters of overflow well in front of sluice, the method of combining theoretical analysis and numerical simulation is used in this paper. The water hammer calculation model of long distance water transfer system including sluice overflow well is established. Through numerical modeling and programming calculation, the characteristics of water hammer controlled by ventilation hole and overflow well in front of gate in long distance water conveyance tunnel are simulated, and the unsteady surge process of ventilation hole and overflow well in front of sluice is obtained under different operation conditions. The whole line extreme pressure distribution. In this paper, the characteristics of surge wave and the pressure distribution of the whole line extreme value are compared when there is a pre-sluice overflow well, and the water hammer protection effect of the overflow well in front of the sluice on the long distance water transfer system is analyzed. In order to optimize the design of the overflow well in front of the sluice, the sensitivity of the overflow well height, roughness coefficient, the plane position of the overflow well in front of the sluice, the inner diameter of the pipeline and the cross section area of the overflow well are analyzed. The effects of various parameters on the pressure distribution, overflow flow and overflow duration of the whole line are analyzed. The results show that the surge height of the ventilation hole and the maximum pressure of the water hammer can be well controlled by setting the overflow well in front of the sluice. The height of the overflow well and the inner diameter of the pipeline are the most important factors affecting the extreme pressure distribution of the whole line. In a certain range, if the height of overflow well is reduced, the maximum pressure of the whole line will decrease correspondingly, but the overflow flow rate and duration of overflow well will increase, and the maximum pressure of the whole line can be reduced by increasing the inner diameter of the pipeline. At the same time, the overflow flow and duration of overflow well can be reduced. In the long distance tunnel water conveyance system, the distribution of extreme pressure can be controlled by increasing the inner diameter of the pipeline and reducing the height of the overflow well, and the overflow process of the overflow well can be adjusted.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TV672.1

【参考文献】