HEAT-AND-POWER ENGINEERING FUNDAMENTALS
V.N. Kovalnogov, U.A. Khakhalev
RESULTS OF NUMERICAL INVESTIGATION OF TURBULENT FLOW WITH THE IMPACTS BASED ON THE FRACTAL DIMENSION OF PRESSURE FLUCTUATIONS ANALYSIS // Transactions of Academenergo. -2014. -N 3. –P. 7-15.
e-mail: kvn@ulstu.ru, ulstu-td-ua@mail.ru
Ulyanovsk State Technical University
Keywords: boundary layer, turbulent flow, modeling, fractal dimension, numerical investigation.
Abstract
As a result of theoretical and experimental research the fractal dimension of turbulent pressure fluctuations had determined, a synthesis of research data of the fractal dimension of pressure fluctuations have produced, the mathematical model of turbulence based on the fractal characteristics of the pulsations have proposed, a numerical investigation have conducted and were received the results. Numerical results using the proposed model based on the fractal dimension of the pulsations are in satisfactory agreement with the experimental data.
S.Z.Sapozhnikov, V.Yu.Mityakov, A.V.Mityakov, S.A.Mozhayskiy, A.A.Gusakov
GRADIENT HEAT FLUX MEASUREMENT: IDEAS, IMPLEMENTATION, RESULTS // Transactions of Academenergo. -2014. -N 3. –P. 16-35.
e-mail: serg.sapozhnikov@mail.ru, mitvlad@mail.ru , andrey.mityakov@gmail.com , mozhay@mail.ru , ray210@mail.ru
St.Petersburg State Polytechnic al University
Keywords: gradient heat flux sensor, cross Seebeck effect, anisotropy, response time, thermal resistance, industrial experiment, PIV-technology, aerodynamic laboratory.
Abstract
It is proposed to measure heat flux with gradient heat flux sensors. The new materials for sensors are proposed. New features and heat flux measurement results in fundamental and applied research are shown: local heat flux measurement in diesel engine, heat flux measurement inside industrial boiler, simultaneous heat flux and PIV-measurement.
POWER GENERATION STATIONS
V.B. Gruzdev
THE WAY TO MAINTAIN THE DESIGN TEMPERATURE COOLING TURBOGENERATOR THERMAL POWER PLANTS // Transactions of Academenergo. -2014. -N 3. –P. 36-47.
e-mail: laktarius@yandex.ru
The Kazan State Energy University
Keywords: electric machine, turbogenerator, losses, joule heat, cooling system, coolant, electrolysis hydrogen, distillate.
Abstract
This article describes a new way of keeping the design temperature cooling system of stator winding and rotor synchronous turbogenerators installed on thermal and nuclear power plants. The method allows regardless of the season of the year, air temperature and cooling water, especially during the summer, keep the design temperature cooling turbogenerator stator winding in the distillate. The use of this method increases the reliable operation of electrical machines, in particular, turbogenerators, without emergency power reduction.
V.I. Sharapov, O.V. Pazushkina, E.V. Kudryavtseva
MASS TRANSFER AND THE ENERGY EFFICIENCY OF LOW-TEMPERATURE DEGASSING OF WATER IN THERMAL POWER PLANTS // Transactions of Academenergo. -2014. -N 3. –P. 48-56.
e-mail: vlad-sharapov2008@yandex.ru , o.pazushkina@ulstu.ru , kudr-e@mail.ru
Ulyanovsk state technical university
Keywords: thermal power plants, deaeration,decarbonization, mass transfer and the energy efficiency,make-up water of heating supply systems.
Abstract
The article describes the technology low-temperature degassing water. This technology can considerably increase the energy efficiency of thermal power station. The desorbing agent in deaerators and calciners is a gas to be supplied to burners of the boiler. Natural gas has very low or negative temperature after the reducing devices. It contains virtually no corrosive gases (oxygen and carbon dioxide), can therefore be successfully used as a desorbing agent in deaeration and decarbonization water. These factors make it possible to do deaeration and decarbonization at relatively low temperatures (10-30оС). Mixing cold deaerated make-up water with reverse heating-system water leads to a significant lowering of the temperature reverse heating-system water before heater lower network and increase the production of electric energy to the heat consumption. This technology can increase the economic operation of thermal power station. The article presents the calculation of the flow rate of gas theoretically required for deaeration and decarbonization and reveals the evaluation of the energy efficiency of the technology for a typical energy unit of thermal power station.
A.F.Shkret, M.V.Garievsky
THE EFFECT OF VARIABLE MODES FOR ECONOMICAL OPERATION OF POWER UNITS // Transactions of Academenergo. -2014. -N 3. –P. 57-68.
e-mail: oepran@inbox.ru
Federal State Institution of Science Saratov center of science of Russian academy of sciences
Keywords: technique, thermal power plants, load regulation, economic life, reliability of power, equivalent to the output of the resource, cost, and efficiency
Abstract
The design procedure, which allows to quantify the impact of variable loads on the reliability and efficiency of the steam turbine units. Investigated the effect of variable modes to measure the equivalent production equipment life and techno-economic performance of the thermal power. The calculated technical and economic performance of the unit for a variety of load control in the daily and weekly sections. The effect of changes in the cost of electricity growth, depending on the mode and the average daily number of hours of discharge (non-use) of installed capacity of power unit.
POWER – AND – MECHANICAL ENGINEERING
V.M.Borodin, G.V.Demidov, A.C.Sachkov, L.Sh.Khairov, A.V.Shcherbakov
ON EXISTENCE OF SPATIAL SIX-LINK MECHANISM WITH A TURNING PAIR // Transactions of Academenergo. -2014. -N 3. –P. 69-77.
e-mail: Bvm45@yandex.ru, german-demidov@yandex.ru , avs7737@kstu-kai.ru
Kazan National Research Technical University named after A.N.Tupolev – KAI
Keywords: spatial six-link mechanism, turning pairs, mobility, spatial symmetry, redundant coupling, connection orientation, Bennett mechanism, Bricard mechanism, symmetry principle, structural analysis, Möbius symmetry.
Abstract
According to the idea of concurrent existence of a spatial six-link Bricard mechanism and a four-link Bennett mechanism, an innovative point of view on the mechanism with redundant ties is developed on the basis of CAD system using the method of instantaneous states with increments of angular coordinates. It has been established that concurrent existence of the spatial six-link mechanism is possible if in one or in three kinematic pairs the links are connected with orientation opposite (symmetrical) to connection orientation of links in remaining pairs; or when one or three links in the kinematic chain are designed to have reflective symmetry of remaining links. Structural analysis yielded that in a closed one-degree-of-freedom kinematic chain with turning pairs there exists symmetry reflecting a structural feature of mechanism – Möbius symmetry. This indicates topological origin of discovered symmetry. Topological Möbius symmetry discovered in spatial structure of Bricard mechanism is a new type of symmetry.
V.N. Shlyannikov, I.S. Ishtyriakov, R.R. Yarullin
DEFORMATION CHARACTERISTICS FOR D16T ALLOY UNDER COMBINED LOADING BY TENSION, COMPRESSION, TORSION, AND INTERNAL PRESSURE // Transactions of Academenergo. -2014. -N 3. –P. 78-90.
e-mail: shlyannikov@mail.ru , ivan_200999@mail.ru
Research Center for Power Engineering Problems of the Russian Academy of Sciences
Keywords: complex stress state, strain fracture criterion, hollow cylindrical specimen, tension, compression, torsion, pressure.
Abstract
A comprehensive experimental study of the limit stresses and strains of aluminum alloy D16T under complex stress state was carried out. Different types of combined loading by tension, compression, torsion, and internal pressure are considered. Interpretation of fracture stress and strain according to the classical theories of strength and ultimate strain is presented. It is found that the deformation criterion of static fracture is preferable to describe the behavior of a hardening material under complex stress state.
ECONOMICS, ECOLOGY, INNOVATIVE TECHNOLOGIES AND PROCESSES IN POWER ENGINEERING
N.A. Lunina
THE RESULTS OF MATHEMATICAL MODELING OF SINGLE-MASS VIBRATION SYSTEM OF DIRECTED OSCILLATIONS BASED ON ASYNCHRONOUS VARIABLE FREQUENCY DRIVES // Transactions of Academenergo. -2014. -N 3. –P. 91- 102.
e-mail: n.lunina@live.ru
Ulyanovsk State Technical University
Keywords: solid fuel furnaces, vibration electric drive, automatic control system, modeling, vibrating machine.
Abstract
A mathematical model of one-mass vibration system designed on the basis of asynchronous oscillations variable frequency drive. A computer simulation of the system with different operating conditions have got in the software package Bauman 3.7. The results of computer simulation of one-mass vibration system have obtained on the basis of asynchronous oscillations variable frequency drive in coasting, braking, and in the case of resonance mode.
Introduction of vibrotehnology on a larger scale is complicated with the lack of effective control systems to ensure the stability of its work, particularly in the resonant mode of oscillation. A special case of the vibration system aimed on oscillations, which is necessary to stabilize the amplitude of, are machines operating in the resonant mode. Resonant modes of vibration machine with forced vibrations practically difficult to implement because of the significant impact of changes in load parameters of the oscillating system.
However, most of the vibration systems operates at frequencies outside the resonance. One of the problems of this kind of systems is the passage of the resonance in the dynamic conditions in which there are mechanical load, having a negative impact on the elements of the system.
The simulation results demonstrate the advantages of dynamic braking to avoid the negative effects of vibration during braking of machine.
The vibration system with automatic control system is considered, showing the search and maintain resonance with changing operating load and the working environment.
N.D. Chichirova, A.A. Chichirov, S.M. Vlasov, H.V. Gibadyllina
NANOTECHNOLOGY IN THE FUEL CELL DEVELOPMENT // Transactions of Academenergo. -2014. -N 3. –P. 103-122.
e-mail: ndchichirova@mail.ru
Kazan state power engineering university
Keywords: fuel cells, alternative energy sources, electrolyte membrane, nanotechnology.
Abstract
The main types of fuel cells to convert chemical energy into electrical energy were discussed. A fuel cell device, the main electrochemical processes in hydrogen and methanol cells were describes. The world fuel cells using classification was given. Modern trends in the development of fuel cells using nanotechnology achievement were presented.
