Crack problem of water turbine runner is expected to be solved

In the past, water turbine runner crack events often occurred during the operation of large hydropower generating units at home and abroad. They have occurred more frequently in recent years, which seriously affected the safety and reliability of the units, and became a major problem that troubled domestic and foreign hydro turbine manufacturers and hydropower application departments. . However, as domestic research accumulation in this area is relatively shallow and systematic reports are rare in foreign countries, the prevention and treatment of runner cracks has become a focus of attention of domestic and foreign water turbine manufacturing and application departments.

The reliability of large Francis water turbine runners is one of the key issues in the design and manufacture of water turbine. Therefore, studying the blade crack mechanism and preventive measures has become an important technical problem that must be solved in the design and manufacture of runners. As one of the representative hydraulic turbine manufacturers at home and abroad, our company sent elite soldiers last year to conduct a three-month real machine dynamic stress test of the water turbine runner in the power station. The static and dynamic stresses under different operating conditions such as load rejection and closing of the cylinder valve and moving water are tested extensively. Through testing, we have understood and mastered the magnitude and distribution of the dynamic stress of the runner, and obtained a lot of first-hand data. At the same time, it provides valuable technical data and scientific basis for further research on the reliability and crack prevention of large runners.

The achievement of the research results also laid a rare technical foundation for the next application to large-scale mixed-flow units on the right bank of the Three Gorges and other large units.