Objective
Optimum use of the hydraulic potential at the agricultural weir in Kehl with innovative turbine design. Axial compact bevel bulb turbines in low-pressure conditions have been used only for up to approx. 24 m3/s and impeller diameter up to 1950 mm of standardized design. In the case of higher throughput either several compact turbines or conventional Kaplan turbines with the shaft brought out horizontally through the suction pipe have been used. Disadvantages of this construction method: more space is required, the machine components have to be assembled in the power house, relatively high hydraulic losses, long erection period, high construction/erection costs. Such disavantages be prevented by using the proposed HSB turbine. The innovative proposal involves the use of a turbine impeller with a diameter of 2400 mm and the addition of a commercially available standardized 1500 RPM generator. Pollution of the waterways is prevented by using biodegradable lubricants or self-lubricating bearings. The gain of efficiency moves in the range of 5%, the payback period comes to approximately 12 years.
The advantages of the innovative proposal are in the use of a single, axially passed compact HSB Turbine for the capacity range 25 to 40 m3/s, running with 160 RPM, at a fall head of approx. 3,5 m, generating approx 1000 kW with high efficiency in particular in the lower part-load area and at full load. The basic idea as to the hydraulic design of the HSBT is the optimization of the overall efficiency across the entire operational spectrum. Hydraulic losses caused by diversion and possible interference caused by the turbine shaft are avoided. In this way the optimum annual power generation is achieved. Power transmission is effected via a planetary/bevel gear, connected to a multi-disk clutch to check overspeeding. This allows the use of a commercially available standardized synchronous generator with 1500 RPM, which is considered an essential innovative aspect of the system.
The intermediate shaft is linked to clutch and generator by two flexible couplings allowing small deflections without detrimental effect.
Environmentally friendly oil, i.e. biodegradable oil, is used on the water-exposed linkage for the adjustment of impeller blades and guide vanes. It is intended to test the field of application and long-term characteristics of such lubricants. The guide vane pivots are lubricated with water and as such maintenance-free.
The compact arrangement of the turbine unit allows for minimum dimensions of the power house, the building space requirements being reduced by 25-30 %. The turbine and gear are preassembled and function-tested at the factory. The unit is delivered in preassembled condition; it can be built in with the help of a mobile crane. A power house crane is not necessary. This in turn reduces assembly time to a minimum. The innovative aspect of the proposal is in the use of proven components in a new kind of arrangement. This new configuration of a Bulb Turbine is to elimlnate existing disadvantageous features, maximize efficiency, optimize environmental compatibility and reduce erection and maintenance costs.
The combination of standardized components of mechanical and electrical engineering to a compact hydro-electrical unit simplifies maintenance and operation and minimizes the expenditures relating thereto.
Programme(s)
Topic(s)
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DEM - Demonstration contractsCoordinator
76005 Karlsruhe
Germany