The present invention relates to a system of bulb turbines, wherein the bulb turbines are each comprised of a generator arranged within a substantially cylindrically designed region of a turbine casing and a rotatably mounted turbine runner coupled with the generator, which are each joined by a draft tube, wherein a plurality of bulb turbines are mututally coupled in a field-like or matrix-like array both in a substantially horizontal arrangement one beside the other and in a vertical arrangement one above the other or mounted in at least one common support, respectively, said plurality of bulb turbines each mounted in a common support being detachably coupled with associated draft tubes.
Bulb turbines of the initially defined kind, which are each substantially comprised of a generator arranged within a substantially cylindrically designed region of a turbine casing and a rotatably mounted turbine runner coupled with the generator, have been known in various configurations, reference in this context being made, for instance, to DE-B 1 503 274, AT-B 326 582, AT-B 345 757 or CH-A 649 348. In those known stationary bulb turbine configurations, such a bulb turbine is mounted in a specially prepared foundation, or in an appropriately equipped second casing surrounding the turbine casing, via usually sturdy anchoring means, wherein additional stabilizing means are required beside accordingly stable supporting means in order to enable the safe mounting of the usually large-dimensioned bulb turbine. Furthermore, it is to be anticipated that in such stationarily installed plants specifically designed structures directly adapted to the respective circumstances are employed and that the replacement of such plants or their use on any other site is not feasible in most cases.
In connection with bulb turbines it is, furthermore, known to provide small-structure and optionally transportable units as may, for instance, be used in tidal power stations. In this context, it is referred to U.S. Pat. No. 4,207,015 and U.S. Pat. No. 4,468,153 among others, wherein such plants comprise additional installations, for instance in the form of special ballast elements, in order to enable an adaptation to different flow conditions, in particular, if used in tidal power stations. Thus, also plants of this type are limited to specific purposes of use and cannot be readily applied to different fields and applications.
From WO 89/00646 a system of bulb turbines of the initially defined kind has, furthermore, become known, in which on an arrangement at a water front a regular array of interconnected parallelly arranged draft tubes is located, on which a plurality of immersible hydraulic engines, in particular turbine generators, each comprising a runner rotatably arranged thereon are provided. A similar configuration of a system of several mutually coupled bulb turbines, may moreover, be taken from U.S. Pat. No. 4,468,153 already mentioned above.
Moreover, U.S. Pat. No. 4,755,690 discloses a system of bulb turbines of the initially defined kind, wherein a plurality of bulb turbines mounted in a common support are coupled with respective draft tubes outside the location of use, whereupon the thus assembled sets are lowered and used for gaining energy.
Furthermore, it is to be anticipated that any adaptation of the output of a bulb turbine to different circumstances and, in particular, an increase in output not only will require a considerable increase in height and width, which basically means a considerable increase in the diameter of the bulb turbine, but will also involve an accordingly excessive increase in length and an increase in the weight of the system.