Том 50, № 2 (2016)

The possibility of changing the scheme for regulating the discharge of water from reservoirs in the Volga – Kama cascade by transitioning to a variable drawdown level depending on forecast inflow, as well as lead time and precision of hydrological forecasts of water inflow. A quantitative estimate of increased water flush volume is presented for the second quarter in the lower reaches of the Volga.

The phenomenon of resonance is described at the upper bracket of the hydroelectric generating unit at the Nizhnekamskaya HPP. The nature of exciting forces that lead to unacceptable oscillations in the support element of a hydroelectric generating unit structure is examined.

New field observation data are present for the temperature of concrete in the Sayano-Shushenskaya HPP dam and of water in the reservoir, which permits the entire range of effects on the temperature state of the first column of the dam to be more completely described.

A diagrammed arrangement of dams and station assemblies for symmetrical HPP are presented. Principal results of the design and 3D hydrodynamic computer simulation of low-head flow in a turbine unit are discussed for a traditional HPP and in a centrally symmetrical turbine unit of symmetrical HPPs, with confirmation of predicted fundamentally higher power efficiency of the new design.

The paper presents the results of the study of a phased model of corrosive wear in metal structures of navigation lock gates and valves. Such studies compensate, to some extent, for the lack of diagnostic information in assessing their remaining lifetime.

This is an experimental study of wet steam flows in a nozzle turbine array with an intrachannel separation system that makes it possible to reduce the amount of erosion-hazardous droplets in a turbine stage. Separation is found to affect the parameters of the liquid phase beyond the array. Experiments were done on a test stand at the Moscow Power Engineering Institute with an initial steam humidity of 6.5% and a theoretical Mach number of M _1t = 0.6 beyond the array. Two separation slots at an angle of 90° to the generatrix of the profile surface were made on the concave surface of each blade in the test channel. The effect of the pressure drops in the slots on the wet steam flow downstream of the nozzle blade array was studied and the flow rates of the separated steam and liquid were measured separately. The efflux of the steam-water mixture into the slot was modelled in the ANSYS Fluent CFD computer code. This yielded a more complete picture of the flow structure in the slot and made it possible to explain the behaviors of the experimentally observed separated steam and liquid flows. The velocity distributions of the liquid phase beyond the nozzle were obtained by particle image velocimetry (PIV). The experimental data can be used to modify the parameters of intrachannel separation systems for steam turbine stages and to increase the reliability and operating efficiency of turbine blades.

Arefined method for designing staged evaporation systems is developed. It allows for the design features (two symmetric sections, salt ratio line, continuous and intermittent blowdown points, etc.) of the external saline sections and the circulation conditions in the saline sections, each having two cyclones on each side of the boiler and being close upon one waterwall (circulation surge). Examples of using the method to improve the reliability of the saline sections are given.

It is shown that the temperature of makeup water in district heating systems has a strong effect on the energy efficiency of turbines of thermal power plants. A low-temperature deaeration process that considerably improves the energy efficiency of thermal power plants is developed. The desorbing agent is the gas supplied to the burners of the boiler. The energy efficiency of the process for a typical unit of thermal power plant is assessed.

The use of the conventional approach to picking set points and the application of classic algorithms for distance protection in a number of cases do not give the required sensitivity, which the computational results presented in this paper clearly show. An unconventional approach to solving this problem is proposed: the simultaneous use of several independent measuring elements in the distance protection step.

The feasibility of heat removal during emergency cooling of a reactor by a forced-draft cooling tower with accumulation of the peak heat release in a volume of precooled water is evaluated. The advantages of a cooling tower over a spray cooling pond are demonstrated: it requires less space, consumes less material, employs shorter lines in the heat removal system, and provides considerably better protection of the environment from wetting by entrained moisture.

Ways of monitoring the bearing journal insulation in turbine generators currently employed in power plants are introduced. It is shown that their practical utilization involves substantial difficulty. It is recommended that the method developed by the firm OOO “NPP Rezonans” be used for monitoring bearing journal insulation and oil film, along with the KPIM-2 and KPIM-R4 systems based on it.