Emergency gates are the last link in chain of safety turbo-groups case distributor failure, safeguarding power station from severe damage. These can be located at turbine intake or outlet draft tube and controlled by gantry cranes hoist hydraulic cylinders. Gates must descend with high flow for a short time to prevent spinning runaway velocity periods longer than admissible, as that would entai...

This paper proposes an original approach to investigate the influence of geometry Francis turbines draft tube on pressure fluctuations and energy losses in off-design conditions. It is based Design Experiments (DOE) steady/unsteady Computational Fluid Dynamics (CFD) simulations internal flow. The test case a turbine unit specific speed Ns=120 m-kW which required operate continuously conditions,...

Bed symmetry has been analysed in fountain confined conical spouted beds operating with fine particles. Thus, vertical particle velocities and the spout shape have determined a wide range of spouting air bed configurations. is widely accepted without draft tubes or nonporous ones, but this not case when open-sided are used. radial velocity profiles differ depending on cross-sectional angular pl...

Abstract In this paper, we investigate the formation of Rotating Vortex Rope (RVR) using scale-resolving methods, SAS and Wall-Modeled LES (WMLES). We compare results from these simulation methods with experimental data Francis-99 workshop. This comparison shows that general features RVR can be captured both methods. However, WMLES would lead to a better quantitative agreement between velocity ...

This paper focuses on the optimization of a Solar-Enhanced Natural-Draft Dry-Cooling Tower (SENDDCT), originally designed by the Queensland Geothermal Energy Centre of Excellence (QGECE), as the air-cooled condenser of a geothermal power plant. The conventional method of heat transfer augmentation through fin-assisted area extension is compared with a metal foam-wrapped tube bundle. Both lead t...