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Contenu archivé le 2022-12-27

REHABILITATION OF TWO KAPLAN S-TUBE TURBINES BY APPLICATION OF LUBRICATION-FREE HUBS AND SPECIALLY ARRANGED BEARINGS

Objectif

Whilst on existing conventional Kaplan-S-Tube Turbines both the shaft bearings and the hubs, along with the adjusting gear of the variable pitch blades are so designed as to discharge surplus lubrication stuff such as leak oil or grease into the river, the Contractor intends to apply lubrication-free hubs and locate the shaft bearings outside the water space. By these means the efficiency and availability of the plant will be improved and environmental pollution minimized.
After the re-commissioning of the turbine on 22.12.1992 some minor leaks had been observed. Within a few weeks the leakages assumed unacceptable proportions. In cooperation with Voith remedial measures had been worked out which proved to be effective so that the modified turbine could be taken over. As from 24.05.1993 the machine is operating commercially.
Summary of the essential criteria which had to be observed :
- Clear-cut separation of oil and water systems,
- Leak oil, if any, to be collected on the atmospheric side,
- Choice of the most suitable material for sealing rings,
- Practicable arrangement of control borings for immediate detection of leakages of both, water and oil.
- Choice of the most suitable sealing water pressure of the hydrostatic sealing in order to minimize wear and tear on the sealing rings. Arrangement of a mechanical indicator for such wear and tear and of a flow controller to monitor the sealing water consumption.
The second low pressure turbine in the Forbach Hydropower Station which is identical to the first one will now be modified in the same way.
Objects of the rehabilitation are 2 Kaplan S-Tube Turbines commissioned 1965 in the Hydropower Station of the Badenwerk at Forbach/Black Forest.
Technical Data : Rated Flow 2 x 14 cbm/s, net head 10.24 m, Rated power output 2 x 1,27 MW, speed 300 RPM, average production 13.335.000 KWh/a.
Modified design of the slide bearings guiding the impeller blades and the regulating system integrated in the hubs : The bearing sleeves are made of special self-lubricated DEVA metal, the journals are made of stainless steel.
Such bearings are considered maintenance-free and highly wear-resistant.
The hollow space inside the hub and the shaft containing the control mechanism for blade adjustment is filled with treated water fed in from a control tank.
Modification of the turbine shaft guide bearings and shafts sealings :
The existing grease lubricated bearing will be re-arranged from the water wetted to the dry area of the Turbine and connected to the existing oil lubrication system of the gearbox and the generator. A hydrostatic shaft sealing will be arranged to separate the water space from the atmosphere. The project will be handled by the Hydropower Department of the Badenwerk in Karlsruhe in cooperation with the technical management of the Hydropower Station in Forbach. Detail design and manufacturing of the required parts will take place at the workshops of J.M. Voith in Heidenheim. After successful conclusion of the technical modifications as outlined above the Badenwerk intends to rehabilitate other hydropower stations under its supervision in the same way. Furthermore, in cooperation with Voith Tolosa the considerable replication potential as existing within the borders of the E.C. shall be utilized for dissemination.

Thème(s)

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Appel à propositions

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Régime de financement

DEM - Demonstration contracts

Coordinateur

BADENWERK AG
Contribution de l’UE
Aucune donnée
Adresse

76005 KARLSRUHE
Allemagne

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Coût total
Aucune donnée