HEAT AND POWER ENGINEERING FUNDAMENTALS
Thermodynamics analysis of elements of the energy complex of gas processing enterprises // Transactions of Academenergo. 2017. N 3. P. 7-22.
I.V. Dolotovsky
e-mail: dolotowsky@mail.ru
Yuri Gagarin State Technical University of Saratov
Keywords: energy complex, processing of gas condensate raw materials, thermodynamic clustering, effectiveness
Abstract
The results of thermodynamic analysis of the elements of systems (of supply fuel, electricity and heat) of the energy complex and of technological system of gas processing enterprises. Performed thermodynamic clustering of the fuel consuming equipment and of the heat exchangers of air-cooling of an enterprise processing sulphurous gas-condensate raw materials. An example of a thermodynamics analysis of energy-intensive of gas purification installation by absorption. The choice of the direction of increasing the efficiency of this installation is shown, which can be realized technically.
METHOD OF CALCULATION OF PARAMETERS OF THE THERMODYNAMIC CYCLE OF THE VAPOR-COMPRESSION COOLING SYSTEM // Transactions of Academenergo. 2017. N 3. P. 23-31.
D.L. Karelin
e-mail: karelindl@mail.ru
Naberezhnye Chelny institute (branch) of Kazan Federal University
Keywords: condensing temperature, cooling system, working substance, difference of temperatures, the compressor, multistage compression.
Abstract
In work offered the new method of calculation of parameters of the thermodynamic cycle of the vapor-compression cooling system which allows reaching its largest productivity and the minimum mass-dimensional characteristics of the compressor. By the offered technique calculation for the working substance freon-10 is made and recommendations about use of the vapor-compression cooling system are made.
INDUSTRIAL HEAT-POWER ENGINEERING
THE EFFICIENCY OF COGENERATION CCGT FOR THE REGULATION VARIABLE ELECTRICAL LOADS // Transactions of Academenergo. -2017. –N 3.-P.P. 32-42.
A.F. Shkret, M.V. Garievsky
e-mail: oepran@inbox.ru
Saratov center of science of Russian academy of sciences
Keywords: combined-cycle CHP plant, gas turbines, thermal loads, variable electrical load, efficiency
Abstract
Considerable irregularity of daily schedules of electric loads and the lack of maneuverable capacities in power systems causes the need to involve base power plants (NPP, condensing power plants and CHP) to cover variable schedules of electric loadings. The article investigates the economic efficiency of bringing combined-cycle CHP to cover variable areas of daily schedules of electric loadings. The developed methodology and evaluated the efficiency of heat transfer from the gas turbine at various modes of its operation for PGU-450Т. Substantiated mode of unloading unit for electricity, while ensuring the nominal heat output and calculated the technical and economic indicators. The study found that unloading units binary cogeneration CCGT for nightly failure load of the power system more efficient unloading of nuclear power, CCGT and steam turbine power units of condensing power plants with supercritical steam parameters.
POWER GENERATION STATIONS
MULTIFUNCTIONAL COOLDOWN NPP SYSTEM BASIS ON HYDROGEN COMPLEX // Transactions of Academenergo. -2017. –N 3.-P.P. 43-52.
R.Z. Aminov, V.E. Yurin
e-mail: urin1990777@bk.ru
Saratov Scientific Center, Russian Academy of Sciences
Keywords: nuclear power, nuclear safety, reservation of own needs, blackout, system failure, hydrogen complex.
Abstract
In emergency situations, accompanied by complete de-energization of the nuclear power plant (including a maximum design accident), an additional low-power steam-turbine combined with a hydrogen complex allows to provide power supply necessary for the cooling of the reactor core. In the regular mode, the additional steam-turbine and hydrogen complex work for the generation of electricity. The authors conducted a preliminary probabilistic analysis of the safety of nuclear power plants when combined with an additional steam-turbine and a hydrogen complex, taking into account the unsteady states of the equipment in emergency mode. As shown by the calculations considered three-channel emergency power system with diesel generators, the additional steam-turbine and hydrogen complex satisfies the second target fixed for nuclear power plants with WWER of new generation. The article shows the result of an annual reduction of damage occurrence risk from an accident with core damage for a variant of combining a three-channel system of emergency power supply of an NPP with an additional steam-turbine and a hydrogen complex compared to a three-channel EPS with a diesel-generator and an additional station-wide diesel-generator. The technical and economic analysis of the investigation system was carried out, taking into account the reduction in the risk of damage and without him.
CALCULATION OF THE ENERGY EFFICIENCY OF ADVANCED CIRCUITS HEATING FEED WATER IN THE REGENERATION SYSTEMS OF STEAM TURBINES CHP // Transactions of Academenergo. 2017. N 3. P. 53-65.
V.I. Sharapov, A.V. Kuzmin
e-mail: vlad-sharapov2008@yandex.ru, antochka1987@yandex.ru
Ulyanovsk State Technical University
Keywords: CHP, cogeneration turbines, water-treatment plants, regenerative steam extraction.
Abstract
Revealed significant reserves of increasing thermal efficiency CHP through enhanced technology flows incremental heating of the feed water of boilers of power plants and makeup water heating systems. In particular, heating of the source water before the water treatment installation in embedded bundles capacitors cogeneration turbines at small gaps in a couple of capacitors often does not provide technologically required temperature of this water before decarbonization and vacuum deaerators. In this regard, the majority of domestic CHP is in fact extremely uneconomical heating of the source water before the water treatment installation steam high-potential production selection of turbines type PT. Proposed new solutions for using low-grade flow of the main condensate steam turbine CHP for heating flows incremental source of feed water boilers and the source of makeup water heating systems. These solutions increase the efficiency of the regeneration system and the efficiency of the power plant due to the additional generation of electric energy on heat consumption. The theoretical and experimental study of energy efficiency and industrial applicability of the proposed solutions use in heating the main condensate steam turbine after regenerative heaters low pressure. To assess the energy efficiency of new schemes associated with the application flow of the main condensate steam turbine for heating the coolant water treatment plants, power plants, and other intra-station unit of the water flow applied the methodology developed in the research laboratory “heat-and-power system” based on the determination of the specific power generation at heat consumption. Developed and registered software products, allowing to automate the process of calculating the energy efficiency of the heating source of incremental water boilers and feed water heating the main condensate of steam cogeneration turbines.
POWER AND MECHANICAL ENGINEERING
ELASTIC AND PLASTIC STRESS INTENSITY FACTORS IN SPECIMENS OF ALUMINUM ALLOYS UNDER TENSILE AND BENDING LOADING // Transactions of Academenergo. 2017. N 3. P. 66-78.
N.V. Boychenko
e-mail: nataboi@ya.ru
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
Abstract
The present paper is devoted to the analysis of material properties, a loading type and geometric parameters of the crack influences on the elastic and plastic stress intensity factors. Subject for studies is central notched specimens with external semi-elliptical surface crack, wide range of relative crack depth (0.3 ÷ 0.8) and aspect ratio (0.3 ÷ 1) is studied. The calculations are carried out under uniaxial tension and a three-point bending for two aluminum alloys D16 and B95. Fundamental differences in the behavior of the elastic and plastic stress intensity factors for surface cracks in the plate are established.
SIX-LINK MECHANISM AS A TOPOLOGICAL PHENOMENON OF MÖBIUS SYMMETRY // Transactions of Academenergo. 2017. N 3. P. 79-87.
V.М. Borodin, А.D. Lustin, L.Sh. Khairov, А.V. Shcherbakov
e-mail: Bvm45@yandex.ru, ADLustin@kai.ru, Khairov37@mail.ru, AVScherbakov@kai.ru
Kazan National Research Technical University named after A.N.Tupolev – KAI
Keywords: spatial pivot mechanism, mechanism mobility, geometric parameter of mechanism, orientability, spatial isomerism, CAD.
Abstract
The paper deals with a spatial six-link mechanism with turning pairs. In particular case, the mechanism exists in the space between two spherical surfaces whose centers are located at the intersections of pivot centerlines and the pivots are located on these two surfaces of the sphere. The spaces in which the links of the mechanism can exist depend strongly on geometric parameters of the latter. In particular cases the mechanism, while transforming, can turn inside out, i.e. it is impossible to tell “right-hand” and “left-hand” objects. In the general case the mechanism can be oriented and other than that identical “right-hand” and “left-hand” modifications of the mechanism are possible.
STRAIN BASED MODEL OF DAMAGE ACCUMULATION UNDER CREEP // Transactions of Academenergo. -2017. –N 3.-P.P. 88-96.
A.V. Tumanov
e-mail: tymanoff@rambler.ru
Kazan Scientific Centre of the Russian Academy of Sciences
Keywords: creep, damage field, damage accumulation.
Abstract
Strain based model of damage accumulation is proposed for both stages of creep. Government parameters of the model are expressed in terms of the Norton equation constants and the time to failure for one level of nominal stresses. Numerical calculation of infinite cracked plate is presented for creep condition with damage accumulation for different biaxial ratios. Three types of biaxial ratio is considered: uniaxial tension, equibiaxial tension, and pure mode II for an infinite plate containing through-thickness crack with radius at crack tip. Based on the numerical result, the kinetics of damage accumulation is presented.
ECONOMICS, ECOLOGY, INNOVATIVE TECHNOLOGIES AND PROCESSES IN POWER ENGINEERING
Study of wood biomass Thermal decomposition // Transactions of Academenergo. 2017. N 3. P. 98-107.
S.I. Islamova, D.V. Yermolaev
e-mail: isvetulia@mail.ru, energoed@mail.ru
Kazan Scientific Center of Russian Academy of Sciences
Keywords: wood biomass, pyrolysis, thermogravimetric analysis, thermal decomposition, kinetic analysis.
Abstract
The results of granulated wood biomass thermogravimetric analysis are presented in the article. These studies were conducted in an inert and air medium at different heating rates. The results of thermogravimetric analysis were used to determine the kinetic characteristics of the process of thermal decomposition of wood biomass on the basis of model-free isoconversion methods. The obtained values of the activation energy differed depending on the degree of conversion and were in the range of 138-242 kJ/mol. Samples of woody biomass were characterized by high thermal stability. Thermal decomposition of wood biomass was regulated by diffusion.
INFLUENCE OXIDE FILMS ELECTROCHEMICAL PROPERTIES ON THE CORROSION RATE OF LOW CARBON STEEL IN THE HEATING SYSTEM // Transactions of Academenergo. 2017. N 3. P. 108-125.
T.V. Kozlova, S.M. Lipkin, M.S. Lipkin, T.V. Lipkina, V.M. Lipkin, A.A. Postnikov, E.SH. Kagan, L.N. Fesenko
e-mail: timskat@mail.ru; kuh-sv82@mail.ru; mail286@mail.ru
Platov South-Russia state polytechnic university (NPI)
Keywords: passive films, impedance, pulsed chronopotensiogramms, X-ray analysis.
Abstract
The purpose of this work included the study of the films structure formed on the inner heating surface by X-ray analysis, gravimetric methods, methods of local electrochemical analysis, impedance spectroscopy, as well as the study of the correlation of the results of the research with the corrosion rate. As a result, it was shown that the protective passivating film is determined by the ability of both its multiple parameters: the phase composition of the surface layer, the presence therein of a high cathodic phase activity; the free surface of shares; electrical conductivity and water temperature. Thus, the diagnosis of the films should be carried out on the results of the local electrochemical analysis (LEA) in the system combined with the fraction of free area (FFA), impedance spectroscopy, x-ray diffraction. Morphology passivating films may be layered or insular nature that the metal layer is determined by the composition of the surface as a result of selective chemical or anodic dissolution, as well as the conditions of transport of the products formed in the passivation film. In conditions of thermal networks by electrochemical corrosion mechanism occurs, wherein the cathode portions are concentrated in the film and the anode on the metal.