Analyzing the Operational Materials on Crack Formation in Blades of Francis Turbines at the Krasnoyarsk HPP

Equipment of the Krasnoyarsk HPP is considered as an example to analyze the dependence of crack formation in runner blades on the operating conditions of the turbines since their commissioning. It was established that intensive crack formation in blades in the initial (running-in) period was due to manufacturing-induced high residual stresses and internal material defects. The blade failure rate increased with water head and, hence, the output of the hydroelectric units. The absence of cracks in the blades today indicates that the lifetime of the runners has not ended yet.