锦屏二级水电站复杂超长引水发电系统水力过渡过程复核计算研究

Study on check computation of complicated hydraulic transients in super-long water diversion and power generation system of Jinping II hydropower station

位于四川省雅砻江下游的锦屏二级水电站装机480万千瓦,第一台机组已于2012年12月投产发电,其引水发电系统四条引水隧洞平均长度16.67km,具有距离长、断面大、规模大等特点,可研阶段做了大量的计算分析工作,招标施工图阶段由于各种原因对引水发电系统相关结构进行了一些重大调整。为确保引水发电系统水力过渡过程的安全可靠性,先后开展了大量的计算分析和模型试验工作。总结回顾了锦屏二级电站的引水发电系统的特点及工程建设中的变化,并对多家单位的计算结果进行了总结比较,分析了电站在大波动工况系统参数的极值、小波动工况系统的运行稳定性、水力干扰工况机组的出力变幅等,研究成果对工程的安全稳定运行有较大应用价值。

Jinping II power station is located on the lower Yalong River mainstream with an installed capacity of 4800 MW, and its first unit was put into power generation in December 2012. It has four water diversion tunnels of average length 16.67km, a water diversion and power generation system that is featured with super-long tunnels and huge tunnel cross sections. At the stage of feasibility study on this system, a lot of computation and analysis have been done; at the bidding and construction drawing stages, major adjustments are made on the tunnel structures for a variety of reasons, resulting in a hydraulic transient process extremely complicated to compute. To ensure the safety and reliability of the tunnel system under hydraulic transients, a large amount of computation, analysis and model test has been conducted in previous studies. This paper summarizes the main characteristics of the system and its modification during construction, compares the calculations by different research institutions, and estimates the extreme values of system parameters for the power plant in large fluctuation conditions, the system operation stability in small fluctuation conditions, and the amplitude of generation output in hydraulic disturbance conditions by comprehensive analysis. These results are very useful for safe and stable operation of the project.