Efficiency Comparison of Alternate Schemes for Take-Off from Low-Head Low-Water Flows

Abstract

A proposed method for conversion of the energy of a water flow to useful power offers a number of advan- tages as compared with a different kind of hydraulic turbines. Graphical relationships between the power of generating units and the flow rate of water are presented. The deficiencies of existing layout when used under the same conditions are described. The energy strategy of the Russian Federation for the pe- riod through 2030 calls for an increase in the utilized per- centage of renewable energy sources. Low-power and decen- tralized power supply with active use of all forms of local and secondary energy resources, particularly in regions of low density, are being developed in conformity with forecast estimates. Moreover, development of small hydroelectric power projects is called for the in the zone of decentralized power supply due to an increase in efficient utilization of local energy resources (1). A new method of converting the energy of local water- power resources is proposed in (2 - 5). The operating princi- ple of innovative generating sets for useful take-off from low-head, low-water flows is based on automated initiation of a periodic water hammer in a conduit, and conversion of its energy into useful power by linear generators established uniformly over the length of the conduit (Fig. 1). Let us com- pare the take-off efficiency with traditional hydraulic tur- bines in a hypothetical example at "anomalously" low heads and flow rates. The length of the diversion conduit in ad- vance of the hydraulic turbine and the length of the innova- tive generating set can be assumed equal to 100 m. According to Bernoulli's equation (4), the pressure gra- dient on the turbine established at the end of the conduit: