Research on the Flow-Induced Stress Characteristics of Head-Cover Bolts of a Pump-Turbine during Turbine Start-Up

Nowadays, pump-turbine units have to experience multiple start-stops every day balance the power production and consumption on grid. During transient process of turbine start-up, hydraulic forces applied head-cover would change dramatically induce high-level stresses bolts. As key components large units, bolts are subjected tens thousands tonnes excitation force during operation. Special attention should be paid design because these high water heads forces. Therefore, safe is extremely important maintain operational safety whole unit. This paper investigates flow-induced stress characteristics start-up in a prototype A complete 3D fluid model corresponding structural model, including unit, were created. The fluid–structure coupling method was used calculate caused by flow start-up. pressure files calculated CFD tool transferred mapped finite element Subsequently, numerically simulated. simulation results showed that increased significantly displacement distributions different not uniform. calculation methods conclusions this can also evaluate for similar units.