NUMERICAL INVESTIGATION OF HEAT EXCHANGE WHEN COOLING UNBREAKABLE METHOD OF METALLIC PREPARATION BY A GAS-LIQUID MEDIUM // Transactions of Academenergo. -2017. –N 4.-P.P. 7-15.
Institute of Mechanics, Ural Branch of the Russian Academy of Sciences
Keywords: heat exchange, cooling, billet, gas-liquid medium, numerical analysis, analysis.
The paper is devoted to a numerical study of heat transfer during cooling of a continuous high-temperature metal billet from structural steel 60C2 by a flow of a gas-liquid medium. The mathematical model of heat transfer is presented in a two-dimensional nonstationary formulation that takes into account the axisymmetry of the flow of the cooling medium relative to the longitudinal axis of the cylindrical metal blank. To solve the system of differential equations, the control volume method is used. Parameters of the flow field of the gas-liquid medium are calculated by the SIMPLE algorithm. For the iterative solution of systems of linear algebraic equations, the Gauss-Seidel method with lower relaxation was used. The results of the study of heat transfer parameters during cooling of an unevenly heated billet are presented. The values of the local cooling rate of the workpiece by the process time are determined.
STUDY OF THE PARAMETERS OF A HYDROGEN-OXYGEN STEAM GENERATOR WITH COOLED COMBUSTION CHAMBER // Transactions of Academenergo. -2017. –N 4.-P.P. 16-23.
Saratov Scientific Center of the Russian Academy of Sciences
Keywords: nuclear power, hydrogen power, hydrogen-oxygen steam generator, CFD code, water cooling, underburning, burning of hydrogen in an oxygen, Ansys, diffusion combustion.
The article analyzes the process of combustion hydrogen in the oxygen environment by the example of a hydrogen-oxygen steam generator with a gross heat output of 6 MW with forced cooling of the combustion chamber. For mathematical modeling of the combustion process, the software complex Ansys and the combustion model of a non-premixed mixture of fuel and oxidizer are used. The main parameters and composition of the combustion products for different geometric dimensions of the combustion chamber and the oxidizer excess coefficients are determined.
It is shown, that an increase the internal diameter and length of the combustion chamber leads to a reduction of underburning due to more efficient combustion of hydrogen fuel. At the same time, the actual underburning is significant due to the dissociation of combustion products due to their high temperature. A study was made of the influence of the oxidizer excess factor on the underburning and the temperature of the combustion products. The minimum required oxidizer excess ratio was determined to achieve an actual underburning of 2%, which was 1.875.
A.G. Laptev, E.A. Lapteva
MODELING OF MASS-SITTING IN MULTICOMPONENT AND BINARY MIXTURES IN THE MODE OF STRONG INTERACTION OF PHASES AT FILM CURRENT IN CHANNELS // Transactions of Academenergo. -2017. –N 4.-P.P. 24-32.
e-mail: firstname.lastname@example.org, email@example.com
Kazan State Power Engineering University
Keywords: mass transfer, multicomponent mixtures, film-type apparatus, strong interaction, boundary layer.
A mathematical model for mass transfer in multicomponent mixtures in the gas and liquid phases of dispersed-annular flows in the regime of strong interaction (gas velocity is 10-40 m/s) is considered. A diffusion boundary layer model is adopted taking into account the damping of turbulent pulsations in the viscous sublayer. As a result, equations are obtained for calculating elements of the matrix of mass transfer coefficients in the turbulent film as well as in the gas flow. Special cases of calculations of mass transfer coefficients are shown and compared with well-known experimental data.
V.G. Krioukov, V.V. Gasilin, V.B. Yavkin
COMBUSTION MODEL OF PULVERIZED COAL IN PLANTS WITH LOW OF EMISSION OF THE POLLUTANTS // Transactions of Academenergo. -2017. –N 4.-P.P. 33-48.
Kazan National Research Technical University
Key words: pulverized coal, mathematical modeling, mixing, combustion, sulfur oxides sulphatization, chemical reactions.
Is developed the mathematical model for pulverized coal combustion in plants with low emission of pollutants, considering the inflow of air by two zones. Were considered the processes: burning in gas phase (the detailed chemical kinetics); moisture evaporation; yield of volatile species; carbon combustion; simultaneous mixing and combustion of hot gas with air; the absorption of sulfur oxides by calcium carbonate. Theoretical calculations were matched with experimental data. Were identified of characteristics and was performed analysis of high-temperature processes in main channel of burning.
I.N. Solomin, A.Z. Daminov
IMPROVING THE EFFICIENCY OF HOT-WATER BOILER THROUGH THE USE OF ORC // Transactions of Academenergo. -2017. –N 4.-P.P. 49-57.
ZAO «NPP «Compressor», Kazan
Kazan Scientific Centre of the Russian Academy of Sciences
Keywords: heating system, the organic Rankine cycle, boiler room, expander, efficiency
Have considered one of the ways to improve the efficiency of hot-water boiler on base a facility operating an organic Rankine cycle (ORC) at the proposed refrigerant R245fa. Such units allow one to generate electricity to cover the auxiliaries of a heat source at a heat-transfer fluid temperature of no more than 130°С. A way to insert this unit into the flow diagram of a boiler plant is proposed. The methodology for the design of turboexpanders and compressors used in the oil and gas industry and their operational data were applied in the analysis of a turboexpander. Have showed the potential use of low-temperature energy (as compared to the classic Rankine cycle) to generate additional electricity in the heat supply systems.
Z. Aminov, A.I. Kozhevnikov
INFLUENCE OF VARIABLE OPERATING MODES, STARTING AND STOPPING OPERATIONS ON RESOURCE GENERATION GAS TURBINES // Transactions of Academenergo. -2017. –N 4.-P.P. 58-66.
e-mail: firstname.lastname@example.org, email@example.com
* Saratov center of science of Russian academy of sciences
** Turbulence and Vortex Dynamics Group, Department of Applied Physics, Eindhoven University of Technology
Keywords: Start of gas turbine, lifetime, equivalent operating hours, cyclic operation
Analyzed the impact of starting-stopping and unloading of modes of gas turbine unit on the basis of equivalent resource generation, reduced to operation at the nominal mode. The most stressed element of the gas turbine is the first stage blades, with the highest stresses under the influence of thermomechanical loads in the basal section. On the basis of the strength calculation of the first stage blades made of Inconel 718 metal, an equivalent production of the gas turbine resource is determined for various loading programs. It is shown that starting after 7 hours of idle time produces a resource 5 times less compared to starting from a cold state.
A.Yu. Vlasova, S.M. Vlasov, A.S. Vinogradov, N.D. Chichirova, A.A. Chichirov, A.I. Lyapin, A.V. Pechenkin, A.I. Minibayev
DEVELOPMENT OF THE METHOD OF REDUCING SULFATE-CONTAINING COMPONENTS IN HIGH-MULTI-GENERATED PROCESSED REGENERATIVE SOLUTIONS OF THERMAL ELECTRIC STATIONS // Transactions of Academenergo. -2017. –N 4.-P.P. 67-76.
Kazan State Energy University
Key words: sulphate-containing components in wastewater, thermal power station, chemical water treatment, highly mineralized spent regenerative solutions, clarifier, ion exchange.
The analysis of methods for reducing sulphate-containing products in highly mineralized spent regenerative solutions of water treatment plants of thermal power plants is carried out. A new method for reducing sulphate-containing components in highly mineralized spent regenerative solutions is proposed. Laboratory studies have been carried out to reduce sulfate-containing components in model solutions. Industrial tests were carried out at a really operating thermal power plant in the Republic of Tatarstan to reduce sulphate-containing components in highly mineralized spent regenerative solutions of the water treatment plant by the developed method. A technology for neutralizing sulphate-containing components was developed, using cheaper, environmentally friendly secondary resources of a water treatment plant.
V.A. Khrustalev1,2, M.V. Garievsky2
POWER UPRATES IN OPERATING NUCLEAR POWER PLANTS WITH WWER REACTORS: STATE, PROBLEMS AND PROSPECTS // Transactions of Academenergo. -2017. –N 4.-P.P. 77-88.
e-mail: firstname.lastname@example.org, email@example.com
1 Yuri Gagarin State Technical University of Saratov
2 Saratov center of science of Russian academy of sciences
Keywords: nuclear power plant, power uprates, main circulation pump, variable frequency drives
Today the process of power uprates in operating nuclear power plants with WWER reactors deserves close consideration due to the high savings achieved in the energy system. The greatest achievements and success in this field have been observed in the USA since the 1980s. The article highlights the initial experience of power uprates of NPPs in the US, evaluated measures for preparing and licensing power uprates and the Russian experience of power uprates of nuclear power plants with WWER, general recommendations for the implementation of power uprates, ways to further power uprates.
ELASTIC AND PLASTIC FRECTURE RESISTANCE PARAMETERS IN SPECIMENS OF ALUMINUM ALLOYS AT LOW TEMPERATYRE // Transactions of Academenergo. -2017. –N 4.-P.P. 89-99.
Kazan Scientific Centre of the Russian Academy of Sciences
Keywords: plastic stress intensity factor, elastic stress intensity factor, surface flaw, uniaxial tension, three-point bend, low temperature
Elastic and plastic stress intensity factors are determined along the front of a curvilinear semi-elliptic crack with a variation in the relative sizes of defects and the loading types at low temperature. Subject for studies is central notched specimens with external semi-elliptical surface crack. Wide range of relative crack depth and aspect ratio is studied. The calculations are carried out under uniaxial tension and a three-point bending for two aluminum alloys D16 and B95 at -60°С. Fundamental differences in the behavior of the elastic and plastic stress intensity factors for surface cracks in the plate are established at room and low temperatures.
CREEP STRESS INTENSITY FACTOR FOR COMPACT TENSION SPECIMEN CALCULATION WITH TAKING INTO ACCOUNT DAMAGE ACCUMULATION // Transactions of Academenergo. -2017. –N 4.-P.P. 100-111.
Kazan Scientific Center of Russian Academy of Sciences
Key words: creep stress intensity factor, damage accumulation, damage field, creep, damage
In this study, a creep damage accumulation model is developed. This model was implemented into finite element program complex ANSYS. Three-dimensional numerical calculations of a compact tension specimen under creep conditions with taking into account damage accumulation are carried out. On the basis of the obtained stress-strain fields, the values of the In-integral are calculated, as well as the distribution of the creep stress intensity factor along the crack front. The possibility of applying the creep stress intensity factor as a fracture resistance characteristic are discussed for creep-damage conditions.
R.R. Yarullin, N.V. Boychenko, A.P. Zakharov
THE FATIGUE SURFACE CRACK GROWTH IN ALUMINUM ALLOY D16T UNDER TENSILE AND BENDING LOADING AT RANGE OF TEMPERATURE // Transactions of Academenergo. -2017. –N 4.-P.P. 112-125.
Kazan Scientific Centre of the Russian Academy of Sciences
Keywords: aluminum alloy D16T, surface cracks, different temperatures, crack growth, plastic SIF, uniaxial tension, three-point bend
The variation of crack growth behavior is studied under tension and bending fatigue loading for the different temperatures conditions. Subject for studies is central notched specimens with external semi-elliptical surface crack. By experimental studies the effects of temperatures on the relations between the crack sizes on the free surface of specimen, crack mouth opening displacements, crack growth rate and aspect ratio were determined.
These relationships are useful for automation of experimental studies of surface crack growth. The classical elastic stress intensity factor (SIF) and new plastic SIF approach were applied to the fatigue crack growth on the free surface of the central notched specimens as well as the deepest point of the semi-elliptical surface crack front. As result principal particularities of the fatigue surface crack growth rate as a function of types of loading and temperature conditions are established.
I.V. Dolotovsky, E.A. Larin
Methodology of synthesis of resource-efficient energy complex of oil-gas enterprises // Transactions of Academenergo. -2017. –N 4.-P.P. 126-139.
e-mail: firstname.lastname@example.org, email@example.com
Yuri Gagarin State Technical University of Saratov
Keywords: energy complex, structure, options, synthesis, mathematical model, algorithm, multicriteria optimization, oil-gas-condensate raw materials, variable modes, resource efficiency
Proposed methods, algorithms and a system of performance indicators for structural and parametric optimization and synthesis of the energy complex of oil-gas enterprises in processing raw materials. Scientific support allows carrying out analytical studies and project work in the field of advanced energy systems, integrated with a technological complex and that are effective at different stages of the life cycle of enterprises.