Том 52, № 2 (2018)

Reconstruction of axial hydroturbines by installing propeller-type blade runners with variable rotational speed is examined. The calculation methodology for energy indicators of such turbines according to their Hill chart is presented. The effectiveness of transferring hydroturbines to operation with variable rotational speed is shown, using the example of the Cheboksary HPP. In this case, power generation increased by 16% using the same volume of water passing through the turbines. At the same time, the turbine adjustment range widens in comparison with the traditional propeller-type units operating at constant rotational speed.

Results of field and laboratory investigations on filling and deposition of sandy soil in water, the results of statistical sounding, and sampling of packed sandy soil in water in the absence of flow and in the case of a moving flow of water as well as following dynamic compaction of soil are presented.

Atechnique of designing a round wall in design by means of which the nature of the operation of the structures and the combined work of the backfill and the wall, the shift (displacement) of the wall, and the angle of internal friction may be taken into account is proposed. The proposed expressions are recommended for use in designing the retaining walls of embankment and fish protection structures.

The results of experimental investigations of seafloor scour near the foundations of gravity platforms under the frontal impact of regular waves and currents are presented. The effect of current velocities on the location of the scour zone relative to the structure is determined.

Results are provided for a study of concrete waterproofness, structure, and properties of cement stone treated with penetrating water insulation system Penetron. It is shown that formation of waterproofed concrete facilitates formation within cement stone pores of an additional amount of low-basicity calcium hydrosilicate of acicular shape and also calcite.

During the reconstruction of the Volzhskaya HPP, it is very important to determine the properties of the concrete and the strength parameters of the structures and buildings of the HPP. During field studies, the durability of concrete under monoaxial compression was measured and the velocities of elastic waves were determined. Based on completed tests, a large amount of data that makes it possible to evaluate the strength parameters of the entire HPP building was selected. According to the results examined in this article, it is possible to predict the formation of defects in concrete. The tendency for the durability of concrete structures in the direction to decline in the direction from the right bank to the left is revealed.

The main design solutions for coal-fired boilers of the Primorskaya TPP under construction are described. Boilers E-240-13.8-560KT with a tangentially fired furnace were designed to burn Kuznetsk bituminous coal and operate as part of 65 MW units. Features of the design coals, main design solutions for coal pulverizing systems, design features of the boiler, and a low-NO_x combustion system are considered. The layout of the boiler and boiler auxiliaries in the main building of the power plant is presented. Particular attention is paid to the aspects of emission reduction and the environmental compatibility of the boiler. The main design solutions for the integrated dry bottom ash removal system that allow using resulting ash and slag materials as saleable by-products are described. The results of 3D-simulation of the burning processes and expected NO_x emissions and unburned carbon are given.

An analytic method of calculating the eigenfrequencies of the vibrations of a stator core based on its representation as a lengthy thick-walled cylinder is proposed. The effective physical and mechanical properties of the core are determined with the use of the method of direct homogenization in order to reduce the dimension in direct numerical simulation of the heterogeneous composite structure of the core.

For single-phase earth faults (SEF) in a generator network, the higher harmonic components are a good information base for relay protection of the generator against single-phase earth faults. Because of the low signal-to-noise ratio, they are not available for direct measurement. Anew method of active-adaptive recognition of similar signals is proposed. The results of testing a prototype of the generator protection device with an active-adaptive analog-to-digital converter (ADC) path confirm the high effectiveness of the proposed method.

A technique of calculating the parameters of a mathematical model of a power system that forms part of the standard software package of the RETOM-51(61) device is considered. The goal is to verify the remote element of the relay protection equipment and emergency control automation system in asynchronous mode. A numerical example is presented of the calculation of the parameters of the model for verifying the serial automation device to exit asynchronous mode of operation in remote mode.

In case of the low volatile content and low heat of combustion of the volatile matter, external factors play a more important role in stabilization of the flame, than in the case of reactive coals. The paper offers a review of solutions for improving the design of the swirl burners, their arrangement and furnace layout.

Gas-insulated and XLPE cable power lines can be used as high-power outputs from power plants and deep inputs of power to big cities. When laying power cables in a populated area, it is important to ensure a low level of electromagnetic field. The magnetic-flux density for specific designs of gas-insulated and XLPE cable lines is calculated for different shield-grounding methods and arrangements of cables. The calculated results are analyzed.