Methodology for reconstruction of hydraulic-turbine equipment at active HPP

Abstract

The problem of reconstruction and enhancement of the technical level of equipment at active HPP requires a complex approach, and, in the general case, calls for studies in the following directions:-replacement of basic water-power equipment with improvement of power-producing qualities of the generating sets;-reconstruction and modernization of electrotechnical and auxiliary equipment with enhancement of technical characteristics (reliability, response time, maneuverability, lowering of production costs, etc.); and, -use of modern control systems for HPP based on computer technologies and systems for the protection of generating sets using microprocessor equipment.The first of the directions indicated defines to the greatest degree the effectiveness of the reconstruction of equipment at active HPP. Considering the above, a methodology is proposed below for replacement of water-power equipment. Criteria for Selection of New Equipment (goal of reconstruction)Replacement of hydraulic-turbine equipment should certainly be accompanied by an improvement in the energy efficiency of the generating sets, to wit an improvement in the capacity or an increase in the generation of electric power from the volume of water passing through the turbines ( first basic reconstruction criterion). Replacement of obsolete and physically worn turbines by analogous machinery fashioned from a higher quality material, but with the same power indicators (replacement of "metal by metal") is considered unacceptable.Simultaneous improvement in the above-cited power indicators has not always been successfully provided. In that case, selection will depend on whether a new turbine with a forced operating regime is adopted, and as a result, an additional capacity with reduced power generation is obtained from the volume of water passing through the turbine, or maximum gain in power generation is achieved from the same volume of water, but at a lower additional capacity (or in general, its absence).Being disposed to power effects as regards power generation and capacity, it is possible to convert to a cost expression for reconstruction effectiveness in terms of an "ith" variant:where s N is the cost of 1 kW of displaced capacity at the replaced power plant, s P is the cost of 1 kW · h of power generated at the replaced power plant, N t.ex and P ex are, respectively, the capacity and power generation of the existing turbine, and N ti and P i are the capacity of and the power generated by the new equipment for the "ith" alternate reconstruction scheme. It is obvious that for this approach, selection of the best alternate reconstruction scheme will be determined by the absolute values of s N and s P .Assessment of the replacement of a hydraulic turbine is, however, insufficient from positions of the attainment of power-producing effects alone. The reliability of the equipment assumes major significance. That which ensures a maximum operational-availability factor K a = K a max for the equipment is considered the optimal alternate reconstruction scheme...