At present (according to the 1993 results) the share of hydroelectric stations in the electric power complex of Russia with respect to capacity amounted to 21.6% and with respect to production to 17.4%, which corresponds to 43.4 million kW installed capacity and 175 billion kWh production.The "Concept of the Energy Policy of Russia Under New Economic Conditions," developed by the Energy Research Institute of the Russian Academy of Sciences and approved by the Russian Ministry of Fuel and Energy (Mintop6nergo) and government of the Russian Federation, which was published in mid-1992, and the "Draft of the Electric Power Program of Russia for the Period up to 2010" developed on its basis in 1993 by the Electric Power Committee of Mintop6nergo are supposed to keep hydropower at about such a level. Both the Concept and Draft were based on the fact that Russia's economy needs a considerable time to recover the increasing rate of its development. Several variants of developing the economy were examined and these variants need electric power production. At the same time the authors of the indicated documents assumed that a substantial decrease of energy intensity (energy/GNP ratio) will occur. An analysis of the development of electric power in countries of the far abroad showed that considerable capital investments to reduce the energy intensity of production were needed for getting out of the energy crisis of the 1970s. Their problem of saving energy was solved as the main one when getting out of the energy crisis. We are supposed to solve the problem of saving energy simultaneously with getting out of the general economic crisis with practically no financing of this problem. This task is impracticable. Thus, during the past two years with a general decline of production the energy intensity of almost all enterprises began to increase rapidly and increased by at least 15%. It is not ruled out that this 15% includes also the unaccounted for squandering of electric power in the present environment of impunity. This circumstance complicated still more the economic situation in the industrial sector, the more so under conditions of equalization of domestic and world prices for fuel and regulated electric power rates.The aforementioned documents, devoting sufficient attention to hydropower, nevertheless did not plan its due development, but reduced its participation in electric power production at the 2010 level to 13.3% (Concept) and to 15.3-16.7% (Draft) versus the 1993 level of 17.4%.These suggestions could be the result Of an economic analysis not taking into account the real dynamics of price changes in the country, which sooner or later will lead us to parity of prices on the world market.An analysis of a comparison of the relative effectiveness of constructing thermal and hydroelectric stations with consideration of the dynamics of price changes on the domestic market is given in the work "Hydropower of Russia Under New Economic Conditions" published in 1994 by the joint-stock company Gidroproekt (State Planning, Su...
Operating experience with hydraulic units at active hydroelectric plants is an experiment with the actual operating conditions of equipment, which cannot be performed under laboratory conditions. The value of this experience consists in the fact that it is a unique source of information on the complex reliability indicators of hydraulic machinery. Statistical analysis of retrospective data makes it possible to trace the dynamics of the variation in power-equipment reliability during operation, to ascertain the effect of individual turbine parameters and mode conditions on the reliability indicators and, in turn, to develop measures for improving the reliability of a similar type of hydraulic machinery at newly designed hydroelectric plants.Complex criteria of power-equipment reliability can be obtained on various principles. For a power unit at a nuclear plant, for example, the supply factor of the scheduled generation of electric power II is proposed as a generalizing reliability indicatorwhere AE is the incomplete release of electric power due to failure of an electric unit, and E is the scheduled generation of electric power in accordance with the prescribed regime.A reliability indicator on the basis of the supply of scheduled power can be constructed in a similar manner. Estimates of the reliability of power equipment in accordance with the stability of the operating performance curves of the units are also proposed --for a hydraulic unit, for example, on the basis of the reduction in efficiency for a certain value due to damages sustained by the section between inlet and outlet.Reliability indicators based on the time of the unit's availability to take up the load and the downtime of the power equipment has come into the most widespread use in international and domestic practice. In this case, the following are initial data for calculation of the complex reliability indicators of a hydraulic unit: the operating time tg e in the generator mode; the operating time t s in the synchronous-compensator (SC) mode; the time tre held in reserve; the total downtime for repair ~tr; the scheduled downtime for repair tr. s. Time dependences are also used in calculating complex reliability indicators and other forms of power equipment: steam turbines, gas-turbine units, etc. By themselves, however, the expressions for calculating the reliability indicators of power machinery and methods of plant-data reduction are equal.The reliability of power machinery is most frequently estimated by the operational-availability factor in accordance with the equation [2,3,[12][13][14]
At present about 25% of hydroelectric stations of the country with a total installed capacity of 8900 MW have been operating for more than 30 years, and 37% of the hydrostations with a total capacity of more than 12,000 MW have been operating for more than 20 years and, consequently, the equipment of these stations is also approaching the end of their standard service life [1].The following characteristics are typical for hydrostations where problems of the reconstruction and reequipping of the units are urgent: the majority of hydrostations are equipped with adjustable-blade turbines, the operating regimes of which on the complete performance curve nl'---Ql' are far from the optimal efficiency with respect to the reduced discharge; at a number of hydrostations the installed capacity of the turbines has been increased by 10-25% in comparison with the design due to boosting the operating regime of the turbines; the statistical distribution of the use of the capacity of a turbine--generator unit N u has shifted in recent years toward high loads in comparison with the design.As a result of boosting the operating regimes of the turbines and changing the operating regimes of the hydrostations, the use of the energy of the stream has worsened, since the weighted average efficiency with respect to generation was 5-10% below the maximum possible for the give type of turbines.Along with a decrease of the efficiency of using the stream and a shift of the operation of the turbines into the zone of lower efficiency values and increased dynamic loads, a tendency toward a decrease of the reliability of the units is observed: an increase of the rate of failure of the blades, an increase of the rate of destruction of the turbine bearings, intensification of cavitation of the waterway of the units, etc. [2, 3].An increase of the efficiency and reliability of the hydropower equipment with a service life exceeding the standard will inevitably require its replacement. The need for replacement is dictated not only by physical wear of the main elements of the units but also by the circumstance that they have become obsolete relative to modem types of turbines, as well as by the changed requirements imposed on hydrostations on the part of the power systems.Problems related to the reconstruction and reequipping of turbines are best solved within the framework of large-scale reconstruction of the hydrostations. This direction should become the main one in the 12th Five-Year Plan and should take over from modernization of individual components of the equipment, which was carried out to provide standard operating readiness of the hydrostations. For the successful solution of problems of replacing turbines during reconstruction and reequipping it is necessary: to evaluate the efficiency of using the stream by the existing turbine equipment under the established operating conditions and for the selected parameters (rotational speed n and diameter of the turbine runner D1); to determine the optimal requirements imposed on the parameters of th...
The gate apparatus unit of hydraulic turbines consists, as a rule, of guide vanes with lower and upper bearings, lower and upper rings, and a kinematic system connecting the vanes with the regulating ring and gate servomotors.The vane bearings are installed respectively in the upper and lower rings of the gate. The upper ring can be made as a separate structural element or be included in the structure of the turbine cover or upper ring of the stator. The latter became widespread in the designs of large turbines. Rigid fastening of the bearing assembly both in the upper and lower ring of the gate apparatus was provided for in the turbines that have been created. Such a design required strict observance of coaxial alignment of the bearings of the upper and lower rings, which could be achieved only by machining the holes for the bearings in the lower ring to match the upper ring of the gate apparatus. After manufacturing the entire gate apparatus unit its control assembly was done at the plant in order to ensure hlgh-quality assembly at the place of installing the turbine.For the turbines of the Riga hydroelectric station the S. M. Kirov Kharkov Turbine Plant proposed the design of a "floating" bearing of the guide vanes in the lower ring (Fig. i).In the proposed design the housing of the lower bearing of the guide vane is installed freely, with a gap of 60 mm on each side, in the socket of the lower ring of the gate apparatus with subsequent alignment, fastening, and sealing with a special concrete and polymer concrete (Fig. 2).The proposed design does not require at the plant during manufacture strict observance of coaxial alignment of the hole for the housings of the bearings in the upper and lower ring of the gate apparatus and control assembly of the entire unit and eliminates machining of the sockets in the lower ring. The latter can be delivered to the hydrostation independently of the delivery of the upper ring of the turbine stator or upper ring of the gate apparatus. The former design of the bearings required during installation the careful alignment of the lower ring of the gate apparatus with the stator to provide the coaxial alignment of the bearings achieved at the plant.In the proposed design, after final installation of all vanes, fastening by adjusting bolts, and checking the end gaps, vane adjustments, and ease of rotation, their final fastening is done by pouring a special concrete between the housing of the lower bearing and socket of the lower ring of the gate apparatus.We will give the technology of assembly for the indicated design. At first, as usual, the guide vanes are uncrated. The factory packinK is removed and the condition of the rubbing surfaces is checked.The vane is placed in a horizontal position and the housing with the upper bearings and the housing with the lower bearing are put on it (Fig. 3).The housing of the lower bearing is drawn up tightly, without gaps, to the end of the vane and fastened in this position by welding two assembly rods (2) to the housing of the bearing and v...
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