In Europe, around 11% of electricity is generated from hydropower every year, but 35% of the potential output is not utilised. As part of the ReHydro research project, Munich University of Applied Sciences is developing new methods for the early methods for the early detection of cavitation, one of the main causes of turbine damage.
Cavitation is a hydrodynamic effect in which vapour bubbles created by a drop in pressure collapse in liquids. If this happens near solid surfaces, such as turbine blades, extreme localised pressures are created that catapult out material like a volcano, leading to material damage. Up to now, cavitation can only be recognised through cost-intensive inspections, during which the turbine has to be completely emptied. If cavitation is detected, the only option left is to limit the damage by increasing the pressures or reducing the flow rate.
To avoid this, operators run the turbines at a large safety distance from critical operating areas where the pressure could drop. However, this limits the operation of the turbine and generates less electrical power than would be possible.
Detecting cavitation at an early stage with the help of AI
As part of the ReHydro project, funded by the EU, Prof. Busboom is working with Voith Hydro and Energias de Portugal (edp) to develop innovative measurement solutions and AI monitoring systems to reliably detect cavitation during operation and reduce expensive inspections. For example, they use ultrasonic sensors that detect the high frequencies generated during the cavitation process.
The technology is being implemented at the Valeira hydropower plant in Portugal and is intended to demonstrate how modern sensor technology and data analysis can optimise the efficiency of hydropower plants. This not only increases the flexibility of the plants, but also supports the stability of the electricity grids by extending the availability and service life of the hydropower plants. ReHydro thus makes a decisive contribution to the ecological and economic optimisation of the European hydropower industry.
