Objective
The treatment plant provides approximately 80000 people with drinking water. The water coming from a barrage reaches the treatment plant with a pressure of approximately 3,5 bar. This pressure is actually being "destroyed" by a rotary piston slide valve. The aim of this project is to make use of this energy potential by recovering the energy.
Conventional turbines for generation of current are too expensive for this purpose. Thus, pumps will be used as turbines, i.e. the pumps are coupled in reverse operation as turbines with asynchronous motors acting as generators.
The valve at the pump inlet as well as the by-pass valve are operated by pressurized water and are thus independent of foreign power supply (this means that they also work in case of power failure).
The two plants operate to our satisfaction. The pressure-water-operated safety valves in the turbine bypass ensure an extremely high level of operating reliability. The electrical control and monitoring systems have been operating reliably since the commissioning of the stations. The project can be considered very successful both from a technical and an economic point of view.
GOTTLEUBA :
Flow rate : 840 m³/h
Head : 20m
Rated output : 34.6 KW
Electrical energy : 450,000 KWh
COTTA :
Flow rate : 540 m³/h
Head : 79 m
Rated output : 87.9 KW
Electrical energy : 750,000 KWh
About 80% of the electrical energy generated by Gottleuba Waterworks are needed for the station's internal consumption, the remaining 20% being fed into the ESAG network.
Since the Cotta station has no major internal consumers, almost the entire electricity is fed into the ESAG network.
The energy recovery principle implemented in the Gottleuba Group Water Supply System can be used wherever pressures have to be reduced (e.g. in the supply lines to an intermediate reservoir in a drinking water distribution network.)
The pump turbines will be designed as base-load machines thus permitting a 24 hours per day operation over the whole year. The required additional quantity will be added under control via a rotary piston slide valve in by-pass according to the quantity leaving respectively the level in the pure water tank.
The electric control plant for power supply is designed in order to comply with all requisites for parallel operation with the EVU. After presentation of the project to the responsible EVU, the ESAG, there is no problem for connection of these plants.
It is planned to renew respectively modernize partly the complete group water supply system, i.e. the water treatment plant as well as the pertaining distribution system with high-level tanks, in order that the produced potable water should come up to the valid laws for drinking water. In the course of the necessary reconstruction work, the energy recovery plant will be incorporated.
At the time being, the "progress lines" are being checked and records being made regarding throughout quantity and pressure by means of a connected computer. Based on these records, the pumps turbines will be designed and the whole system dimensioned.
GOTTLEUBA :
P=43,2 kW (max.above 44 kW)
Q=909 m³/h
E=409.300 kWh (since start)
COTTA :
P=84 kW (max.above 110 kW)
Q=592 m³/h
E=700.000 kWh (since start)
Programme(s)
Topic(s)
Data not availableCall for proposal
Data not availableFunding Scheme
DEM - Demonstration contractsCoordinator
1796 PIRNA
Germany