In June 2019 the first half-axial DIVE-Turbine (HAX) was commissioned in Arignac in the south of France. The power plant Moulin d’Arignac has an installed capacity of 500kW at 29m of head. The new DIVE-HAX-Turbine is replacing a Francis-Twin-Turbine that was to be refurbished. The project is a cooperation between the French company 2EI, specialist on power plant controls, and DIVE Turbinen GmbH & Co. KG from Germany.
The half-axial DIVE-HAX-Turbine is a double regulated turbine for medium head. It is speed-regulated and can therefore be operated from 10% of the nominal discharge. First measurements after commissioning showed a turbine efficiency of 65% already at 14% of discharge and an efficiency higher than 90% at full load. The values prove that the new DIVE-HAX-Turbine reaches highest efficiencies at any operation point and thus, maximum annual revenue will be reached. The new type of turbine is a real alternative to existing solutions of two Francis-turbines in combination or a crossflow turbine. In comparison tot wo Francis-turbines the cost of civil works and turbine technology are significantly lowered. In comparison to a crossflow turbine the overall efficiency and thus the annual revenue are clearly maximised.
The hydraulic principle of the DIVE-HAX-Turbine had already been developed in the 20th century. Still, it was not an economic solution due to the complex and repair-intense mechanical system for runner blade adaptation. In the DIVE-HAX-Technology the mechanic system for runner blade adaptation is replaced by electronic regulation of runner speed. This solution could be established as an economic solution due to the progress in control technology. DIVE Turbinen GmbH & Co. KG have intense experience in the fieldof electronic regulation of hydro power plants and were therefore able to develop the DIVE-HAX-Technology to marketability. More than 40 DIVE-Turbine with electronic regulation are already on the grid.
The advantage of electronic regulation is not only the reduction of mechanic complexity. Especially the growth of renewable energies requires system services to maintain stability of the grid at alternating load conditions. The electronic regulation of the DIVE-Turbine allows to offer system services for example for frequency and tension regulation. It is suitable for application in ecological hydro reservoirs. By reversing the runner speed the turbine can operate in pump mode and therefore pump water into a reservoir during electricity surplus. In times of less electricity production the pumped water can flow back through the turbine and by this produce electricity for the grid stability.
The DIVE-HAX-Turbine can be applied at heads from 20m up to 120m with an installed capacity from 300kW up to 4MW per turbine.
Picture gallery Moulin d'Arignac