GB487850A - Method and system for utilising tidal energy - Google Patents

Abstract

487,850. Utilizing tidal energy. CAQUOT, A., and DEFOUR, A. Sept. 21, 1936, No. 25668. Void. Convention date, Sept. 26, 1935. [Class 69 (i)] The invention relates to methods of obtaining energy from tides in which water impounded in a storage bay as the tide rises is delivered to turbines, the tail water from which is passed to a drainage bay which is emptied into the sea at low tide, and consists in increasing the available head for operating the turbines by pumping water to the storage bay and from the drainage bay at certain parts of the cycle of operations. Fig. 1 shows the cycle, the upper, middle, and lower curves showing respectively the level of water in the storage bay, the sea, and the drainage bay. Commencing at the left-hand point N on the upper curve, the storage bay supplies the turbine, until the level of water in it becomes equal to that of the tide at C. The storage bay is then cut off from the turbine and from C to I is filled from the sea. At I, just after high tide, the storage bay is cut off from the sea and filled by pumping to the level K. At the point L it is again connected to the turbines, which it continues to supply until the level in it has again fallen to C. During the period C to L, represented by a broken line portion of the upper curve, the turbine is supplied directly from the sea. Considering now the lower curve, from P to F the tail water from the turbines flows into the drainage basin, the water level in which rises until at F it is equal to that of the tide. Here the tail water from the turbines is delivered direct to the sea, and the drainage bay is emptied into the sea until just after the point of low tide A, when it is cut off from the sea and pumped out to a level O. At the point P it again receives the tail water. The tail water from the turbines is delivered directly to the sea during the period F to P represented by a broken line on the lowermost curve. The method is stated to enable smaller turbines to be employed and greater power to be obtained. Fig. 2 shows diagrammatically an arrangement of bays and turbines for use by the method, in which the power-house Z is arranged between a receiving bay A<1> and tail bay D<1>. The receiving bay is fed through valves B<1>, C<1> either from the sea W or from the storage bay Y, and the tail bay discharges through the valves E<1>, F<1> to the sea or the drainage bay X. The storage and drainage bays are connected to the sea through the valves G<1> at the appropriate times.