Vol 51, No 6 (2018)
- Year: 2018
- Articles: 20
- URL: https://journals.rcsi.science/1570-145X/issue/view/15317
Hydrotechnical Construction
Field Observations of Soil Settlements, Displacements, and Pore Pressure in Dams
Abstract
The authors have collected publications devoted to field observations of dams, and compared the results with field data of the Nurek HEPP in order to assess the quality of dam construction in comparison with other dams built in the USSR and abroad.
Article
Analytical Method of the Hydraulic Calculation of the Flow Rate of a Venturi Channel
Abstract
Results of hydraulic studies of a Venturi flume are presented. A method is proposed for calculation of the flume flow rate, with error less than 1%. The proposed method of calculation is compared to the method according to the regulations of the State Standard of the Russian Federation MI 2406–97.
State of Concrete Dam of the Krasnoyarsk Hydropower Station After 50 Years of Operation
Abstract
Problems related to the state of the concrete dam of the Krasnoyarsk Hydropower Station are considered. Results of field observations of the state of the dam are presented. The composition of the control and measurement instrumentation and characteristics of the concrete in the dam are presented.
Switching Capabilities of the Units of Pumped Storage Hydroelectric Power Stations with Asynchronized Synchronous Motor Generators
Abstract
The conditions of power control of the hydraulic generating units of pumped-storage hydroelectric power stations with the use of the capabilities of asynchronized synchronous motor generators are considered. Characteristics that relate the size of the permissible surge in load in emergency control with limitations on the permissible deviation of the rotational speed of the hydroelectric generating units are obtained.
Development of Seismoacoustic Method of Quality Control of Placement of Rubble-Clayey Soils in a Dam Body
Abstract
The results of combined geotechnical and geophysical studies of compacted rubble-clayey soil conducted on an experimental embankment for the purpose of developing a seismoacoustic method of quality control of the placement of this soil in a dam body are presented. Recommendations on determining the soil parameters being inspected are given.
Investigation of Variants of Optimizing the Temperature Regimes of Nuclear Power Plant Cooling Ponds by Numerical Methods
Abstract
The results of numerical hydrothermal modeling of the temperature regimes pf the cooling ponds of the Rostov NPP and fifth unit of the Novovoronezh NPP are presented. The STREAM-3D software package is used in the study to calculate the three-dimensional fields of stratified flows and temperatures in a hydrostatic approximation. Variants of optimizing the thermal regimes that reduce the temperature at the NPP external cooling water intake system are proposed.
Research of Sphero-Formation over Pores with Contact Uplift of Clay Soils
Abstract
When calculating dam filters from soil materials with clayey antifiltration elements, it is proposed to consider formation of stable spherical arches on the filter-soil boundary, and the plasticity and properties of the clayey ground that is protected from uplift by the filter. The results of the experiments can be used for improved calculations in accordance with the recommendations of SP (SNiP) and GOST.
Model Hydraulic Studies of an Improved Turning Apparatus for Channels with Rapid Flow
Abstract
An improved turning apparatus for channels with rapid flow is proposed. A description of a laboratory flume and model of the turning apparatus are presented. Graphical relations of the depths of the flow behind a bend in five transverse sections along four verticals are constructed as a result of hydraulic studies of the model of the turning apparatus. Results of investigations of the velocity structure of the flow in the apparatus are presented. Graphs of the variation of the relative velocities vav/v0 of the flow beyond the apparatus are constructed. The results of the investigations confirm the effectiveness of the improved turning apparatus for channels with rapid flow.
Increasing the Efficiency of Forming Coatings on the Working Rotor Blades of Steam Turbines1
Abstract
The article is devoted to an analysis of the characteristics of the KGB-5M electric-spark plant developed by the authors for use in the formation of erosion- and abrasion-resistant protective-reinforcing coatings on the leading and trailing edges of the rotor blades of the steam turbines of thermal and atomic power stations. It is shown that an increase in the thickness of electric-spark coatings and the efficiency of the plant may be produced by decreasing the “stray” inductance of the external discharge circuit and through rational selection of new wear- and erosion-resistant synthetic materials. The results of metallographic investigations of coatings produced by the KGB-5M plant are presented. The KGB-5 plant, which consists of a low-voltage vessel and a high-voltage vessel, was developed to achieve electric safety in the formation of coatings in closed metallic vessels (for example, in the capacitor of a turbine).
Parametric Computational Studies to Decrease NOx Emissions in Combustion of an Ideal Fuel Air Mixture with Management of Several Stabilization Zones1
Abstract
The present article is the first of a series of articles concerned with computational studies on optimization of the process of combustion of a fuel air mixture with temperatures of the gases at the exit from the combustion chamber of around 1600°C where the emission requirements are satisfied. Results of calculations of the combustion of an ideally mixed fuel air mixture in a combustion chamber of typical design possessing several flame stabilization zones formed by swirling of the flows of two swirl nozzles and sudden expansion of the flow in the space of a flue tube are presented. The influence of the position and form of the flame, the concentration and the different variants in which the fuel air mixture is fed into the combustion chamber, the input temperature, preheating in the combustion chamber, swirling of the flow, occupation time, and the pressure and mass of the recirculated flow on the formation of nitric oxides and the completeness of combustion is investigated. Dependences of NOx emission on different influencing factors are obtained. Using the results obtained we are able to estimate the minimally possible level of nitric oxide emissions attainable with a standard optimized design of single-zone combustion of an ideally mixed fuel air mixture. A further decrease in NOx emissions is possible through the creation of two or more sequential zones of fuel afterburning in a depleted oxygen-based oxidant. The form and position of the front of the flame and the completeness and length of combustion of the fuel as a function of the above factors, enabled by varying the design of the combustion chamber while maintaining stable and complete combustion of the fuel, are investigated.
Investigation of the Oxidation Process of the Absorption Solution in Ammonia Flue Gas Desulfurization Technology
Abstract
The results of the study of the oxidation process of the absorption solution in ammonia flue gas desulfurization technology at various process temperatures and ammonium sulfate concentrations in the presence of substances formed during the corrosion of equipment and as a result of the combustion of fuels are presented. Based on the experimental data obtained, technological measures aimed at intensifying the oxidation process are proposed.
Standard Control System for the PJSC “Turboatom” K-300-240 Turbine
Abstract
Fundamental solutions for improvement of the hydraulic section of the control system for the PJSC “Turboatom” K-300-240 turbine, which is equipped with a standard electronic part of the control system from JSC “Interavtomatika.” Results from tests and normal operation are presented.
The Basic Results of Alignment and Summary of Operations of the Main K-1000-60/3000 Turbine Unit with a Small Number of Bearings at the Bushehr Nuclear Power Plant
Abstract
The results of vibration alignment and the first years of use of the prototype K-1000-60/3000-3 turbine unit of the Bushehr NPP in 2011 – 2016 are examined. As a result of conducting an extensive set of studies and actions, the claimed high-quality operating characteristics of the new design bearings that were used and the high degree of vibrational reliability of the turbine unit were confirmed, and these made it possible to ensure successful commissioning on a short timeline, despite the novelty of the design and the uniqueness of development of the majority of units, taking into account the integration of the equipment with the existing base and the condenser group. During the commissioning work, it was shown that this turbine unit is not inferior in any manner to turbine units of analogous power from other firms.
Analysis of the Specifics of Selecting Relay Protection and Automatic (RPA) Equipment in Distributed Networks with Auxiliary Low-Power Generating Facilities
Abstract
Specifics of the distributed networks with auxiliary low-power generating facilities consist in electrical proximity of the generating units (GU) and consumer electrical receivers, which, therefore, share the transient processes, while the parameters of such processes heavily depend on both GU and load parameters. This paper provides the results of analysis of the challenging technical issues associated with the GU integration into such networks with respect to selection of the relay protection and automatic equipment.
Possibilities for Optimizing the Self-Starting Process of Auxiliary Electric Motors at a Nuclear Power Plant
Abstract
The existing technique of switching on the auxiliary reserve network of an NPP formulates the switch-on commands directly after a shutdown. Due to delay in activating the automatic switch, the command is completed with a certain time delay. The nature of the subsequent processes is not very predictable. It is proposed to determine, based on developed computer models of the actual equipment, the moments of formation of the reserve activation commands, thus ensuring smaller perturbations at the subsequent switch-on.
Assessing the Sensitivity of Relay Protection
Abstract
An assessment of sensitivity of the measuring elements of relay protection was performed. Based on simple examples of the generator-transformer unit protection from symmetrical short circuits, it was shown that the sensitivity factor is not a sufficiently objective measure of sensitivity of the relay protection. It was suggested to use a more objective measure, which is a characteristic of sensitivity to transient resistance at the fault location (dependence of the transient resistance, at which the protection stops tripping, on the fault location).
Thermal Power Plants
Comparison of Single- and Twin-Shaft CCPPS
Abstract
The main advantages and disadvantages of single- and twin-shaft CCPPs are analyzed, taking into account various configurations and thermal efficiency and controllability. Single-shaft configurations with and without freewheeling clutch between the electric generator and the steam turbine are considered. Single-shaft 370 – 420 MW CCPPs operated in Russia are compared with twin-shaft units of the same capacity.
Power Systems and Electric Networks
Evaluation of System Effectiveness for Unloading at Nuclear Power Plants
Abstract
The electrical consumption schedules and the structure of the installed power of the Unified Power System (EES) of Russia are examined. The operating costs of nuclear power plants compared to combined cycle (steam-gas) plants as a function of the depth of nighttime unloading at different times in the fuel campaign of nuclear power plants are calculated. It is shown that running nuclear power plants with variable loading is economically unfavorable compared to unloading of combined cycle plants; in addition, at the end of a campaign, the unloading of a nuclear power plant is limited and requires deeper unloading of the unit all the way to stoppage, which leads to greater system costs.