D.I. Pashchenko, O.I. Chastikova, V.V. Gorokhov
EXPERIMENTAL INVESTIGATION OF AERODINAMICS OF A THERMOCHEMICAL REGENERATOR CATALYST BED // Transactions of Academenergo. -2018. –N 1.-P.P. 7-17.
Samara State Technical University
Keywords: aerodynamic resistance, methane conversion, thermochemical regeneration of heat, energy efficiency.
The schematic diagram of a high-temperature plant with thermochemical waste heat recuperation, working according to the regenerative principle, is considered. One of the concerns in the engineering calculations of such plants is the determination of the aerodynamic resistance of the catalyst bed in a thermochemical regenerator. Based on the series of experiments, the dependence of pressure loss on air velocity for different types of catalyst bed filling is determined: chaotic filling, filling with ordered rows, chess filling. For all the methods of filling, the characteristic quadratic dependence of the pressure loss on the velocity Δp = f (w2) is observed. It has also been experimentally established that the pressure loss is linearly dependent on the amount of catalyst loaded into the bed. From the point of view of the classical representation of fluid dynamics, pressure losses in the catalyst bed can be considered as local hydraulic losses, which are caused by changes in the shape and size of the channel, which deform the flow. Based on the experimental data, the values of the local resistance coefficient of the catalyst layer 100 mm long were determined. For a chaotic filling of the catalyst, ζ = 140 … 160; for ordered filling by the series ζ = 75 … 85; for chess filling ζ = 70 … 80. The obtained results can be used in engineering calculations of the method for increasing the energy efficiency of heat and heat power plants, which is based on the thermochemical transformation of the thermal energy of flue gases into the chemical energy of the new synthetic fuel, as well as in the calculations of chemical reactors for methane vapor conversion.
V.N. Petrov, A.A. Shabalin, S.L. Malyshev, S.V. Petrov
VERIFICATION OF METHODS FOR CALCULATING TURBULENT FLOWS IN A CYLINDRICAL CHANNEL // Transactions of Academenergo. -2018. –N 1.-
e-mail: firstname.lastname@example.org, email@example.com, firstname.lastname@example.org, Petrov_1972@mail.ru
FGUP “All-Russian Research Institute of Flow Metering”, “BRiZ” Ltd.
Keywords: verification, boundary layer method, axisymmetric channel, co-current flow, turbulent jet, numerical method, experiment.
The paper considers a verification of numerical and boundary layer methods for calculating the structure of a flow formed as a result of interactions between a turbulent non-isothermal jet and a co-current flow in a cylindrical channel. The calculation results are compared with the experimental data. The calculations were carried out in jet flow regimes with and without the formation of reverse current zones in the proximity of the channel wall. The paper presents calculation results and their comparison with experimental data only for the mode with the formation of return current zones. It also features a comparison of the preparatory work performed by a researcher during calculation with the use of different methods. An algorithm for calculation using the boundary layer method is presented. ANSYS Fluent software complex was used in calculations with the application of the numerical method. In general, flow structure calculation results obtained using the two methods are in good agreement with the experimental data. However, there are significant inconsistencies in terms of flow separation.
Boyan Boyadjiev, Christo Boyadjiev
A NEW APPROACH TO MODELING THE CATALYTIC PROCESSES IN INDUSTRIAL COLUMN APPARATUSES // Transactions of Academenergo. -2018. –N 1.-P.P. 27-41.
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Institute of Chemical Enineering, Bulgarian Academy of Sciences
Keywords: new approach, modeling, catalytic processes, industrial column apparatuses.
The new approach to modeling of catalytic processes in the column apparatus is presented, using convective diffusion and average concentration models. They are created on the basis of the physical approximations of the mechanics of continua, where the mathematical point is equivalent to an elementary physical volume, which is sufficiently small with respect to the apparatus volume, but at the same time sufficiently large with respect to the intermolecular volumes in the medium. The convection-diffusion models allow a qualitative analysis of the processes, rejection of the experimental subtle processes and identification of process mechanisms. The average concentration models allow a quantitative analysis of processes. They contain two parameters that reflect the effect of the radial uniformity of the velocity distributions and it is possible to be obtained, using experimental data.
V.O. Zdor, R.F. Kamalov, Yu.V. Karaeva, A.I. Kadyirov
INVESTIGATION OF CIRCULATING HEATING OF MAZUT // Transactions of Academenergo. -2018. –N 1.-P.P. 42-49.
Key words: fuel oil and heat power plant and boiler house, circulating heating, fuel oil, energy saving.
Kazan Scientific Centre of Russian Academy of Sciences
The results of a numerical study of heating oil in a 628 m3 reservoir with a different arrangement of the pressure pipeline are presented. The following mass costs are considered: 4.1 kg/s, 6.2 kg/s, 10.3 kg/s and 14.5 kg/s. It is established that the dynamics of the mean volume temperature in the reservoir is the same, despite the difference in the picture of the velocity and temperature fields. The necessary heating time is determined depending on the capacity of the circulation pump. A comparison of the numerical results with the experimental data of Geller ZI is presented. The example of the problem of circulating heating of cracked residues.
OPTIMIZATION OF NIGHT MODE OF GTU OPERATION UNDER MULTI-PURPOSE COMBINATION FROM NPP // Transactions of Academenergo. -2018. –N 1.-P.P. 50-56.
Saratov Scientific Center, Russian Academy of Sciences
Keywords: nuclear power, nuclear safety, reservation of own needs, blackout, core damage, gas turbine.
In this paper, the system of NPP own needs reserving based on a gas turbine was investigated. In emergency situations, accompanied by complete de-energization of the nuclear power plant (including a maximum design accident), gas turbine allows to provide power supply necessary for the cooling of the reactor core. In the regular mode, gas turbine works for the generation of electricity. The author investigates the operation modes of the gas turbine that reserve NPPs own needs at night off-peak hours of the schedule of electrical loads. The economic advisability of unloading regimes is determined by a number of factors: night tariff for electricity, increased turbine wear in the modes of unloading and shutdown, start-up costs, decrease of the reliability of the backup of the NPP’s own needs during emergency de-energization during the idle period of the gas turbine. The wear of the turbine and the start-up costs have an order of magnitude less, therefore, to select the optimal operating mode, only the reduction in the night tariff and the reliability of the backup power supply are taken into account.
A.N. Bairamov, V.S. Kirichkov
COMPOSITION SOLUTIONS INVESTIGATE OF COMBINING NPP WITH ENERGY COMPLEX USING HYDROGEN FUEL BY CRITERION MINIMAL RISK // Transactions of Academenergo. -2018. –N 1.-P.P. 57-72.
Federal State Budget Institution of Science Saratov Scientific Center of RAS
Keywords: atomic power station, energy complex using hydrogen fuel, explosion-fire safety, damage, risk.
The goal of the article is to estimate the total annual risk from the explosion and fire of a mixture of hydrogen with an oxidizer at combining nuclear power plants with a energy complex using hydrogen fuel. The risk assessment was carried out using statistical data on the intensities of the appearance of an emergency event due to seal failure and destruction of equipment and pipelines of industrial enterprises. Principal schemes of combining nuclear power plants with a energy complex using hydrogen fuel are given. The effective conditions are determined for the composition of the main equipment and pipelines of the energy complex using hydrogen fuel under which the total risk can be reduced by 1-2 orders of magnitude.
A.A. Genbach, D.Yu. Bondartsev
LIMIT THERMAL FLUXES AND THERMAL STRESSES IN POROUS COATINGS OF A HEAT-ENERGY INSTALLATION // Transactions of Academenergo. -2018. –N 1.-P.P. 73-80.
Almaty University of Power Engineering & Telecommunications
Keywords: heat exchange, porous structure, voltage, cooling system, thermal power plants.
Annotation. The methods and devices for power plants and the creation of scientific methods have been developed. Investigations of the limiting heat fluxes in metallic and poorly heat-conducting porous structures operating under the combined action of gravitational and capillary forces and cooling various devices of thermal power plants are carried out. Based on the solution of the problem of thermoelasticity and experimental data, the mechanism of destruction of metal steam generating surfaces and poorly heat-conducting coatings of small porosity made of natural mineral media (granite) is described. On the basis of the analogy of the phenomena, the dependences of the heat fluxes on the time of their action and the depth of penetration of temperature disturbances are revealed. Capillary-porous systems have high intensity, high heat transfer ability, reliability, compactness. The results of calculations and experiments showed that the maximum thickness of the particles that break off under the action of compression forces for coatings from granite is (0,25÷0,3)х10-2 m. Sections of compression curves that determine the separation of particles with dimensions greater than 0,3х10-2 m for large heat fluxes and short delivery times are screened by the melting curve, and in the case of small heat fluxes and significant time intervals, the expansion curve. The research is aimed at the creation of porous cooling systems from well- and poorly-heat-conducting materials.
EXPERIENCE OF CREATION AND OPERATION OF HORIZONTAL AND VERTICAL TYPES STEAM GENERATORS FOR NPP // Transactions of Academenergo. -2018. –N 1.-P.P. 81-89.
Peter the Great St. Petersburg Polytechnic University
Keywords: steam generators of horizontal and vertical type, multiple natural circulation, level fluctuations, tubes of heat-exchange bundles, the collectors of the coolant, spacing gratings, moisture separator, steam-water mixture, feed water, thermal fatigue and corrosion damage, denting.
The work purpose is development of recommendations on creation of the steam generators for the promising Russian NPP power units with VVER wide range of electric power, including 1500-1800 MW. Analysis of the Russian experience in the design and operation of horizontal steam generators VVER-440 and VVER-1000 has been done in the article. There is discuss physical processes and design features associated with the failure of steam generators: the development of cracks, damage cold the collectors of the coolant, small stocks and fluctuations of water level in the second circuit.
There is described negative processes in the development of foreign vertical steam generators with beams of U-shaped tubes, the lower ends of which are seamed into the tube board: stress corrosion cracking of the walls of the tubes, denting upon evaporation of water in the gaps between the heat exchange tubes of the beam and hole spacing gratings.
Based on the analysis of foreign experience of operation of steam generators of the vertical type, the conclusion about the feasibility of creating an alternative to the horizontal type of the Russian model of the steam generator vertical layout, which can be prototype of serial devices.
N.D. Chichirova, A.A. Chichirov, A.M. Gribkov, A.A.Filimonova, A.S. Vinogradov
MATHEMATICAL ANALYSIS OF ZAINSKAYA HPS JSC “TATENERGO” WATER RESERVOIR-COOLER EFFICIENCY OF THE WORK // Transactions of Academenergo. -2018. –N 1.-P.P. 90-104.
Kazan State Power Engineering University
Keywords: reservoir-cooler, Zainskaya HPS, recirculation cooling system, temperature regime, cooling water circulation efficiency
The reliable functioning of the cooling reservoirs is the key to the high-quality operation of the power plant with a given capacity. Zainsk reservoir-cooler was created on the Stepnoi Zai River in 1965 as a cooling reservoir at Zainskaya HPS. Significant changes took place during the past period with the reservoir: siltation of the bottom, reduction of the reservoir volume, formation of extensive shallow water, etc. The listed processes are connected with influence of activity of Zainskaya HPS on a water basin. In the summer months, the average water temperature in the Zainsk reservoir exceeds the current state standard requirements, which negatively affects the functioning of the reservoir and the operation of the HPS itself. In the article, mathematical calculations are performed with an analysis of the efficiency of the Zainsk reservoir-cooler. The obtained results indicate the need for additional methods of cooling the circulating water entering to the Zainsk reservoir.
I.S. Ishtyryakov, R.R. Yarullin
INFLUENCE OF DEFECT ORIENTATION ON FRACTURE CHARACTERISTICS IN THE HOLLOW CYLINDER UNDER COMBINED LOADING Transactions of Academenergo. -2018. –N 1.-P.P. 105-118.
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Kazan Scientific Centre of the Russian Academy of Sciences
Keywords: aluminum alloy D16T, surface cracks, internal pressure, crack growth, plastic SIF
Cyclic tests of hollow cylindrical specimens of an aluminum alloy D16T with longitudinal and transverse external surface defects are carried out. The tests were carried out at room temperature. It was experimentally established that the form of the crack front stabilized by the loading cycles for various initial notches. The kinetics of displacements and crack opening under cyclic pressure are established.
Differences in the crack growth rate in a hollow specimen under tension and internal pressure are established.
CREEP CRACK GROWTH PREDICTION METHOD // Transactions of Academenergo. -2018. –N 1.-P.P. 119-130.
Kazan Scientific Centre of the Russian Academy of Sciences
Keywords: strain energy density, fracture process zone, creep stress intensity factor, creep crack growth rate.
Creep crack growth prediction method based on creep stress intensity factor is proposed. The object of the study is a compact tension specimen. The crack front shape changes during crack growth was established from creep-fatigue tests. Relationship between crack length and In-integral was obtained from finite element solutions based on experiment data. Concepts of the strain energy density and creep stress intensity factor was used to fracture process zone size determination. This in turn makes possible to predict a crack growth rate. Obtained results have a good correlation with experiment data.