大石峡水电站进水口叠梁门分层取水试验研究

为分析电站进水口采用叠梁门型式分层取水方案的可行性，本文通过1：21.05的水工模型对大石峡水电站叠梁门分层取水进水口水力特性进行了系统研究。主要研究内容包括对不同叠梁门高度取水时，进水口的水流流态、叠梁门体的压力分布、叠梁门顶及竖向流道的流速分布、进水口段总的水头损失系数等。试验结果表明：电站进水口设置叠粱门后，叠梁门顶水头大于18.0 m时不产生有害吸气旋涡，门体压力分布接近静水压力分布；进水口段的水头损失在1.17~1.30 m之间；靠近叠梁门门顶部位的水流流速较大，表层水流流速较小；叠梁门后不同高程竖向流道的水流流速接近于梯形分布，主流偏于进水塔靠下游挡墙侧。在进水口设置叠梁门进行分层取水方案是可行的。

Model tests on the multi-level power intakes of Dashixia Project

In order to analyze the feasibility of application of the stop-log-gate at the water intake, the hydraulic characteristics of the multi-level intake flow in Dashixia Hydropower Station was studied based on a 1/21.05 hydraulic model test.In this test, the intake flow pattern, the pressure distribution on the intake gate, the flow velocity above the gate and in the vertical flow passage, as well as the total water head loss through the intake, were studied under normal power generation and water diversion conditions.The tests show that no harmful suction vortex is detected when the water head over the gate is greater than 18.0 m, and the pressure distribution is close to the hydrostatic pressure distribution.When the head loss of the intake section is between 1.17 m and 1.30 m, the flow velocity near the top of the stop-log-gate is larger, and the surface flow velocity is smaller.The flow velocity in the vertical channel at different elevations downstream of the stop-log-gate is close to the trapezoid distribution, and the main flow is inclined to the side of the intake tower near the downstream retaining wall.Through the relevant model test, the feasibility of the application of the stop-log-gate at the water intake is verified.