卷 51, 编号 5 (2018)

The article gives the results of investigating the hydraulic regime downstream of the concrete armoring of the lower pool combined with the surface spillways of the powerhouse of the Kama HPP. The investigations were carried out on physical and mathematical models as well as directly on-site. The investigations established the conditions under which occur the most unfavorable effects on elements of the riprap riverbed armor beyond the apron cutoff wall, at the base of the foundation slab of the right-bank abutment, and in the base of the right-bank slope of the tailrace channel, highest near- bottom flow velocities and wave heights during idle discharges, and characteristics of the eddy zone near the right bank. Recommendations on providing further safe operation of the HPP are given.

This article presents the results of numerical modeling of seepage in an earth dam with a clay-cement concrete diaphragm for assessing the seepage strength of soils in transition zones at the contact with the diaphragm in the case of the occurrence of a vertical or horizontal crack in its body.

A new method of calculating filtration in earth-fill dams on permeable foundations with impervious diaphragms has been developed. Various ratios of water permeabilities of soils of the dam body and its foundation were observed. Results were obtained that coincide (with a difference up to 3 – 4%) with the data from test hydrodynamic grids (the ÉGDA method). The methodologies of K. Bashkis, Nguyen Xuan Truong, and A. M. Mkhitaryan provide inadmissibly great errors (up to to 45% and above) and cannot be recommended for engineering calculations.

Questions regarding the adaption of the dam of the Sayano-Shushenskaya hydroelectric power plant once the designed normal pool level had been reached in 1990 are considered. The impact of natural and technogenic factors on this process at different periods of operation of the structure (prior to repair of the dam and foundation (1990 – 1996), during repair (1996 – 2003), and following repairs (2004 – 2012) are investigated. Causes for amplification of asymmetry in operations between the left-bank and right-bank parts of the dam are established. Data attesting to the existence of a stabilized state of the structure in 2013 – 2016 are presented and conditions that will prevent the development of unrecoverable processes in the near future are formulated.

This project developed and built a hydraulic actuator prototype with an automated control system for moving the lifting and lowering gates of a shipping lock. In the course of the design engineering, a hydraulic actuator was experimentally developed. Trial operation of a hydraulic actuator was conducted on Lock No. 26 of the Balakovo RGSiS. This design of a hydraulic actuator is recommended to be used in upgrading and designing locks of hydraulic engineering constructions.

Questions related to uncertainty in initial information that arise in reliability assessement of concrete gravity dams on bedrock foundations are considered from the standpoint of structural reliability theory. An application of the proposed technique of reliability assessment of structures is demonstrated, using as an example one section of the dam of the Krasnoyarsk hydroelectric power plant. It is shown that through a transition from a deterministic to a probabilistic method and further on to a possibility method a correct reliability assessment can be achieved under the conditions of high levels of uncertainty of the initial data.

Questions related to the determination of the flow rate of coolant in the pipelines of electric plants are considered. Amethod of determining the flow of single-phase coolant for the case of an asymmetric unstabilized velocity profile that is present following a bend in a pipeline is proposed. Results from the use of the proposed method in novel experiments on the testing unit of the Élektrogorsk Scientific Research Center and in the steam pipelines of power unit No. 3 of the Balakovo nuclear power plant are presented.

Questions related to the production and use of fine and ultra-fine grinded dust are the focus of considerable discussion in contemporary power engineering. These types of dust could be used in the future in kindling and lighting up the tongue of a flame in coal-dust boilers and even replace gas in certain technological processes. However, fine dust is often used today in the power engineering industry through implementation of three-stage combustion processes (called “reburning”). This method of combustion, which is intended to limit discharges of nitrogen oxides NO_x, presupposes the creation of reduction zones through the delivery of additional fuel. The use of dust is becoming increasingly widespread in European countries and the United States, where the cost of gas is extremely high. Medium-run mills with dynamic dust separators are generally used in these countries to produce fine dust. Until recently, experience with the start-up, troubleshooting, and operation of these mills has been entirely lacking in Russia. The present article discusses the experience gained by JSC All-Russia Heat Engineering Institute in start-up and troubleshooting of MVS-195 medium-run roller mills with dynamic separators installed in TPE-223 boilers in the new 225-MW blocks of the Cherepet’ state regional electric power plant.

Development of new methods of automated coordination of traditional step-type protection and multidimensional protection based on statistical principles is necessary for creation of an effective system of relay protection for advanced power supply systems with a complex topology. A graphical-analytical method is proposed for automated calculation of the settings for multidimensional protection based on the matrix representation of the set of protection and protection zones, and an example calculation is given.

During its operation, the Minsk CHP-4 branch of Minskénergo RUE implemented many different measures to improve the technical and economic performance indicators and to increase the efficiency of both the installed turbine and boiler equipment and the plant as a whole. The device being used for cleaning condenser tubes by porous rubber balls is a preventive ecologically friendly means for maintaining a clean cooling surface of the condenser tube systems.

The efficiency of installation of the phase-shifting transformer (PST) in the power supply system of St. Petersburg and the Leningrad Oblast’ is examined, making it possible to execute power flow management within the specified range and limit short-circuit currents to values that do not exceed the breaking capacity of the switching equipment. Its optimal parameters were found, based on analysis of various PST operating modes. Proceeding from this, design calculation of the magnetic core and transformer windings was performed.