| 摘要: |
| 【目的】研究阻抗式调压室的阻抗孔过流特性对水力过渡过程的影响。【方法】针对阻抗式调压室的工程实例，结合三根支洞共用调压室的工程特点，利用特征线法进行计算，建立合理的边界条件方程，对同一特征工况下不同阻抗孔流量系数（0.65,0.70,0.75）、直径(3.0,3.5,4.0 m)组合条件下及不同阻抗孔高度（2,6,10 m）的机组转速升高率、蜗壳末端压力升高率、调压室涌浪水位进行分析与比较。【结果】大波动工况下，随着阻抗孔流量系数和直径的变化，机组转速升高率、蜗壳末端压力、阻抗板压差、调压室涌浪的最大和最小水位均有变化，其中当阻抗孔流量系数为0.7、阻抗孔直径为3.0,3.5,4.0 m时，对应的蜗壳末端压力升高率为35.41%，32.02%，31.26%，对应的最高涌浪水位为715.05,717.16,718.95 m。水力干扰条件下，流量系数相同，阻抗孔直径由3 m变为3.5 m时，阻抗孔面积增加，被2台机组甩负荷干扰的机组出力摆动减小2%~3.5%。阻抗孔高度对阻抗板压差、机组调节保证参数以及调压室涌浪水位的影响甚微。【结论】当阻抗孔直径为3.5 m、流量系数为0.70时，阻抗孔过流特性较好，调节保证参数满足设计要求，调压室内涌浪水位特征值在电站运行允许范围内。 |
| 关键词: 水电站 阻抗孔 过流特性分析 调压室波动 水力干扰 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金项目(51279162) |
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| Flow characteristics of restricted orifice in surge chamber |
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ZHANG Xiaohong,DIAO Xuefen,ZHANG Junfa
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| Abstract: |
| 【Objective】The effects of flow characteristics of the restricted orifice in the surge chamber on the hydraulic transient process were studied.【Method】Based on a project example of restricted orifice surge chamber and combination with engineering features of three adits sharing surge chamber,the characteristics line method was used to create reasonable equations for boundary conditions and analyze unit speed maximum lift,volute end pressure and surge level fluctuation with different restricted orifice flow coefficients(0.65,0.70,0.75）,diameters (3.0,3.5,4.0 m) and height（2,6,10 m） under the same condition.【Result】Under large fluctuation,unit speed maximum lift,volute end pressure ,restricted board pressure difference and the highest up and the lowest down surge level have changed because of the changes of restricted orifice flow coefficient and diameter.When the flow coefficient was 0.7 and the diameters were 3.0,3.5,and 4.0 m,the relative volute end pressures were increased by 35.41%,32.02%,and 31.26% with maximum surges of 715.05,717.16,and 718.95 m,respectively.Under hydraulic disturbance,the restricted orifice area increased when the diameter changed from 3.0 m to 3.5 m,while the output swing of unit disturbed by the other two load rejections was reduced by 2%-3.5%.Changing restricted orifice height had slight effect on restricted board pressure, surge level and regulation assurance parameters.【Conclusion】When restricted orifice diameter was 3.5 m and the flow coefficient was 0.7,the flow characteristics of restricted orifice were improved.The calculation of guaranteed regulation met the requirements and surge level was in the range of power operation. |
| Key words: hydropower station restricted orifice flow characteristics surge level hydraulic disturbance |
