Research On The Unsteady Flow Caused By Power Plant Operation And Its Influence On The Downstream Navigation Conditions

After the completion of Xiangjiaba hydropower station, to meet the requirements of electric power load, the power station discharge in the days will change at any time, at the same, time power station and dam flood discharge will also make discharge mutation, resulting in obvious unsteady flow. It will change the river natural flow characteristic under the dam, the dam downstream channel, port and the normal use of navigation facilities and bring important influence on navigation of the ship. Therefore, study on the unsteady flow influence in the downstream navigation conditions, is very important for the safety of ship navigation and operation.In this paper, I take the Shuifu River in the downstream of Xiangjiaba as the research object. Firstly, according to the measured data, the river physical model is established, and the similarity of the model is verified and the verification results show that model and the prototype was consistent, can meet the needs of the test. Then I take the unsteady flow test and formulate18kinds of power station daily regulation conditions and the5kinds of accident conditions. I assessed the water level amplitude, rate, change of water level, the highest and lowest water level, velocity and gradient change, flow changes. In addition, this article also has carried on the ship model experiment.Based on test data measured by comprehensive and analysis, I got the influence of unsteady flow in the downstream navigation under different operating conditions. The results show that18operating conditions influence the downstream channel navigation condition and port wharf berthing operation in different levels. Contrastly, under the working condition of1,7,13, the daily water level range and water-level variability in short time are small. It is less effect on the downstream channel and dock. And under the working condition of6,12,18, the daily water level range and water-level variability in short time are the largest, its impact on the downstream channel and dock is also the largest. For the power station accident operating condition, when water level falls down too much or discharge is less, it will significantly reduce the downstream channel dimensions, affect the normal navigation of the ship. When flow suddenly falls down, the downstream river close to the dam formed a steep fall water wave, wave by the surface of the water in the path of volatility, easy cause shaking of the vessel, has a short effect on normal navigation of the ship. When water wave gets through the dock, it can lead to cable fault, ship capsized accident, affects the operation safety of the ship seriously. This paper also puts forward the corresponding measures and suggestions for improving navigation conditions.