卷 50, 编号 5 (2017)

A method is presented for changing over from a single-layer shallow-water model to a multilayer model with hydrostatic pressure profile and, then, to a multilayer model with nonhydrostatic pressure profile. The method does not require complex procedures for solving the discrete Poisson’s equation and features high computation efficiency. The results of validating the algorithm against experimental data critical for the numerical dissipation of the numerical scheme are presented. Examples are considered.

Experimental results on steel-reinforced concrete penstocks with different ratios between the cross-sectional areas of the inner steel lining and the hoop reinforcement are presented. The formulas for the strength analysis of steel-reinforced concrete penstocks are improved to, in particular, take into account failure of the bond of the steel lining and reinforcement to concrete.

The methods for the physical and numerical simulation of wave action on maritime structures developed at B. E. Vedeneev All-Russia Research Institute of Hydraulic Engineering are described.

Laboratory studies of the filtration characteristics of clay-cement concrete materials for constructing filtering diaphragms of earth dams by the method of secant piles are reported. Areas for further study aimed at improving the quality of construction, increasing operational safety, and developing a standards base for the design, construction, and operation of these systems are discussed.

A method for measuring the natural frequencies of the arch-gravity dam at the Sayano-Shushenskaya Hydroelectric Power Plant based on data from a seismometric network is described. Experimental and computational determinations of the natural frequencies are compared. It is shown that the calculated values are more sensitive to changes in the upstream water level than the values derived from the field measurements.

Experience with certification testing of steam and combined cycle power plant equipment is described and information is provided on major studies by VTI on the operation of the equipment in frequency and power control modes.

Results of tests on the TPE-208 boiler with and without a high-pressure preheater are presented. It is shown that, because of the presence of bubbler-scrubbing systems in the separation schemes of high-pressure boilers, the steam capacity of the baffles is higher than that of the boiler for saturated steam. Under certain conditions (constant circulation surges, delivery of 100% of the feed water to the bubbler-scrubbing system, higher thermal absorption at the surface, etc.), this leads to reduced circulation reliability. Recommendations are developed for increasing the reliability of the temperature regime for the heating surfaces.

The problem of extending the service lifetime of a large number of steam turbines currently in operation is examined. The difficulties in designing cooling systems for double-flow medium pressure cylinders in high-power steam turbines are pointed out. The history of the creation of systems for cooling double-flow medium pressure cylinders at NPO CKTI is described. The current designs of forced cooling systems for rotors are illustrated and their operating principle is described. Data on the introduction of cooling systems for double-flow medium-pressure cylinders for high-power steam turbines and on their effectiveness in increasing the service lifetime of these turbines are presented.

The use of automatic points of sectionalizing (APS) — reclosers — of the distribution grid significantly increases the reliability of electricity service of the distribution grid of regional grid organizations. The procedures and algorithms for optimizing the arrangement of APS in order to increase the structural reliability of the grid in order to create a distribution grid that adapts to changes in the magnitude and character of the load, secure automatic reconfiguration of the grid including in post-accident regimes, optimize the capacity distribution of the power centers, and in a number of cases serve as a less expensive alternative to modernization of the grid itself are examined.

The Russian regulations on the implementation of best available technologies for large fossil-fuel firing plants are reviewed. The importance of developing effective domestic firing technologies and gas-cleaning equipment for Russian thermal power plants is shown.

The development of electric power systems has raised the requirements of relay protection — sensitivity, speed, and reliability of functioning—for all types of short circuits (SC). The raised requirements can be satisfied by using more complete damage information extracted during the traveling-wave stage of the transient process accompanying SC. The experience gained in working out directional traveling-wave relay protection is generalized and questions concerning the use of traveling-wave principles for developing smart relay protection networks with complex topology and devices making it possible to control power flows in ac lines are examined. An algorithm is proposed for tuning out external SC and determining the damaged phase by using modern methods of digital signal processing.