Design and engineering services
in hydromechanics and hydroelectric
W.P. turbine by the fish lift of Precy Saint Martin
A work for fishes to get over dam which produces electricity
In order to make the dam of Précy Saint-Martin on the river Aube passable by piscicultural fauna, we installed a fish elevator there.
After analysis of the site, it appeared judicious to install it on the left bank of the dam for benefiting from an available existing civil work.
We installed a submerged turbine generator with integrated closing device in order to limit the works of civil engineering. It functions all or nothing (fixed blades and stationary feeder) on the same principle as the submerged pumps. This system, very adapted to turbine a constant flow of 2 600 l/s under a head of 4.20 m, produces an electric power of 80 kW permanently (~8 000 h/year with 10% removed for various stops); that means a potential production of 640 000 kWh/year.
Elevator
A device to capture the fishes is placed in an attraction flow downstream of the work and is lifted up periodically. The water tank formed by the bottom of this cage is then poured upstream of the work. The repositioning of the cage in its downstream position marks the end of the cycle controlled by an automat. The attraction flow is used to actuate a micro hydroelectric power station.
Turbine generator
The group does not have any mobile parts for regulation, which is a proof of longevity. All pieces in contact with water are stainless steel.
The wheel and the asynchronous generator are on the same axle and turn at 500 tr/min. The bearings and the generator are pressurized with air; this pressure is higher than the pressure of ambient water; in the event of a problem with the sealing, the leak will be detected and will cause the stopping of the turbine.
The bearings and sealings are designed for 10 years minimal lifespan.
Oil and greases exchange are made from surface every 1 to 5 years according to the products used.
Closing device
A cylindrical gate sliding parallel to the driving shaft closes waterways very tightly. It plays the role of a guard valve for the emergency stops.
Draft tube
A divergent cone placed immediately downstream of the wheel will ensure its optimal output. This metal sheet draft tube is bent in order to be integrated in the existing work without modification; its exit is directed directly on the cage.