流量对事故闸门门体水力荷载影响数值模拟研究

Numerically simulative study on effect of flow rate on hydrodynamic load of emergency gate

抽水蓄能电站事故闸门动水闭门可靠性及门体水力荷载特性一直是闸门设计和运行中的核心问题,本文通过数值模拟,对响水涧抽水蓄能电站上库进水口事故闸门在不同事故流量工况下动水闭门过程的门体水力荷载进行研究,并与模型试验结果进行比较分析,相同事故工况的数值计算成果和模型试验成果吻合较好,表明采用RNG k~ε模型和VOF方法对平面闸门动水关闭的非恒定流过程进行数值模拟能够取得较好的结果。数值模拟计算结果表明流道的过流量对事故闸门门体水力荷载影响显著,初始事故流量越大,闸门动水关闭过程中闸门区满流向明流过渡时刻的闸门相对开度越大,闸门上游底缘上托力越小,事故闸门动水闭门的持住力相应越大。事故流量由151 m^3/s增大至800 m^3/s时,闭门持住力增大约20%。计算分析结果可为相关闸门的设计和运行提供参考。

Through the relevant numerical simulation,the hydraulic load on the body of the emergency gate for the intake of the upper reservoir of Xiangshuijian Hydropower Station during the dynamic water closing of the gate under different operation conditions of accident flow rate is studied herein. Thereafter,a comparative analysis is made between the result and that from the model experiment concerned; which is demonstrated that the results from both the numerical calculation and the model experiment are better coincided. It is indicated that a better result can be obtained from the numerical simulation made on the dynamic water closing of the plane gate during the condition of unsteady flow with RNG k ~ ε turbulence model and the VOF method. The calculation result from the numerical simulation shows that the effect of the flow rate through flow passage on the hydraulic load of the gate body of the emergency gate is significant; that is to say,the larger the initial accident flow rate is,the larger the relative opening degree of the gate during the transition of the full flow in the area of the gate to the open channel flow in the process of the dynamic water closing of the gate is to be,while the smaller the uplift force of the upstream bottom edge of the gate is,the larger the holding force of the dynamic water closing of the emergency gate is to be. When the accident flow rate is increased from 151 m^3/s to 800 m^3/s,the holding force for the gate closing is increased by about 20%. The results of the calculation and analysis can provide references for the design and operation of the relevant gates.