Development of a counter-rotating turbine to recover the energy lost in release valves of water supply
The project focuses on the development of a new axial counter-rotating turbine for small-hydro applications to recover the energy lost in release valves of water supply. A site characterized by low discharge and high head normally requires the use of a hydraulic machine with low specific speed (e.g. Pelton type). Nonetheless, nonconventional concepts, such as in-line multi-stage axial turbines, can also work efficiently under such operating conditions with the advantage of reduced initial infrastructure investments. Indeed, each stage recovers a fraction of the available head.
The development of a compact full in-line version is ongoing at the HES-SO Valais-Wallis in collaboration with the EPFL-LMH. The electrical generators adapted to the “bulb” and “Straflo” configurations are considered. The main goal is to come up with a range of turbines, equipped with efficient electrical generators and driven by smart controllers, able to recover a maximum of energy with an optimum efficiency.