Heat transfer enhancement in channels with discrete roughness elements under the pulsating flow regimes
I.A. Davletshin, A.K.Kirilin, N.I. Mikheev
Key words: channel with discrete roughness, unsteady flow regime, heat transfer enhancement, flow pulsations, frequency of pulsations, amplitude of pulsations
Abstract
Experimental setup for the study of heat transfer in a channel with discrete roughness elements has been developed. Test experiments in a smooth channel and a channel with discrete roughness elements have been carried out. Data on heat transfer under pulsating air flow regimes have been obtained. Additional heat transfer enhancement associated with the superimposed flow pulsations in the channel with discrete roughness elements has been established.
RHEOLOGICAL CHARACTERISTICS OF RUBBER MIXTURES BASED ON SKI-3 AND SKMS30-ARKM15
A.A.Kaynova, E.K.Vachagina
anastasiya-kaynova@mail.ru, evachagina@mail.ru
Research Center for Power Engineering Problems of the Russian Academy of Sciences
Keywords: rubber compound, extrusion, flow curves, shear stress, viscosity, strain rate, pseudoplastic fluid.
Abstract
The process of rubber compounds extrusion is widely used in the manufacture of rubber goods (MRG) as well as the manufacture of other plastic products. This process is costly and energy intensive. A general technological task is to predict rubber and rubber compounds behavior when they are processed at the factory equipment and to develop optimal working regimes and their quantitative parameters. This problem is usually solved by carrying out laboratory tests as it is the only way to consider all the optimal regimes and solutions. Another way to solve the problem is to use appropriate mathematical models and theories of elastomer processing which describe very complex rheological properties of elastomers together with different technological processes and enable to determine with reasonable accuracy the main regime parameters relying on material properties, structural characteristics of the equipment and specified processing conditions.
Rubber mixtures are studied using a Monsanto MPT capillary rheometer 100. Widely used mathematical models for thermoplasts and elastomers are considered. Flow curves and rheological state equations needed to calculate heat transfer processes and hydrodynamics in the flow of rubber compounds in complex channels of extrusion machines were obtained experimentally.
EVALUATION OF frictional resistance IN RING CHANNELS WITH CONTINUOUS SPIRAL WINDING
V.L.Fedyaev1, S.E.Tarasevich2, I.V.Morenko1
1Institute of Mechanics and Engineering, Kazan Science Center, the Russian Academy of Sciences
2Kazan State Technical University (KSTU)
Keywords: ring channels, spiral insert, calculation of friction coefficient
Abstract
Equations for calculating of friction coefficient of ring channels with spiral inserts presented in the literature are considered. The given equations were analyzed and simplified in some cases. The results obtained by different dependencies were considered and compared with experimental data. Certain regularities in the behavior of the drag coefficient when changing the winding step of the spiral insert are marked.
IMPROVEMENT of OPERATING CONDITIONS OF heat- EXCHANGE EQUIPMENT in condensate and feed system OF a HEAT STATION
V.I. Sharapov, M.A. Malikov
vlad-sharapov2008@yandex.ru, ul_sim@rambler.ru,
Ulyanovsk State Technical University
Keywords: the vacuum system of the turbine, operational control of airtightness, aero-steam blend, regenerative heaters, condenser, recycling of condensate, seal cooler, the improvement of economic efficiency
Abstract
The problems of the air tightness of the vacuum system in turbines as well as rational use of the heat supplied to the condenser with different steam flows are shown to be urgent. Removal of non-condensable gases from thermal power plants heaters is studied. New means for quick detection of places where air is sucked into the equipment operating under vacuum conditions are suggested. More than that, efficient ways to use the heat supplied to the condenser with recirculating condensate flow and technologies of steam-air mixture extraction from regenerative heaters are considered in the paper.
OPTIMIZATION METHOD FOR LOADING MODES OF STEAM COPPERS WORKING PARALLEL TO ONE ANOTHER WITH SOME UNITS KEPT IN RESERVE AND PRESET POWER SUPPLY MAINTENANCE
R.Z.Aminov, S.V. Novichkov, A.I.Kozhevnikov
oepran@inbox.ru novishkovsv@mail.ru kogevnikov_and@mail.ru
The Saratov state technical university
Keywords: optimal distribution, vector-gradient, account characteristics, level of power supply reliability, distribution function.
Abstract
The article focuses on the method of optimal load distribution between steam-generating installations working in parallel. Optimization is done on the total amount of fuel consumed by all installations of the system being considered. A vector method is chosen as an optimization method. Boiler units with identical reliability indicators and equal nominal steam capacities are examined. Reliability requirements on the steam supply to the customers are taken into account during the optimization.
Effectiveness of combining gas turbine plants and nuclear power plants with VVER
Z.Y. Novikova, V.A. Khrustalev
oepran@inbox.ru, zoi87@rambler.ru
Department of Energy Problems, Saratov Scientific Center, Russian Academy of Sciences, Saratov State Technical University named after Yu.A.Gagarin
Keywords: capability increase, nuclear power plants, combined cycle gas turbine, gas turbine, heat storage, live-steam overheating prevention, phase transition accumulator.
Abstract
The problems of combining nuclear power plants (NPP) with gas turbine plants (GTP) and the advantages of such combined-cycle plants are discussed in the paper. A scheme of a turbine power plant where a nuclear power plant block is combined with the reactor VVER-1000, the K-1000-60/1500 turbine, two gas turbines and a system of phase transition accumulators (SPTA) is developed. Different variations of the scheme and steam parameters at the nodal points are considered. The advantages of the proposed combined-cycle plant with the system of phase transition accumulators are shown. Initial results of the analysis of the efficiency of the combined plants and its dependence on the described operation conditions of the power complex “GTP + NPP + SPTA” are given.
ONE- PARAMETER DIFFUSION MODEL of a thermal power-station- OUTDOOR THERMAL NETWORK
Chichirov A.A.*, Chichirova N.D.*, Filippov I.E.**, S.M.Vlasov*,
ndchichirova@mail.ru, vlasovsm@list.ru
* Kazan State Power Engineering University
**Kazan (Volga region) Federal University
Key words: One-parameter diffusion model, flow reactor of ideal displacement with recycle, thermal power-station system − outdoor thermal network
Abstract
Mathematical description of processes in a thermal power-station system − outdoor thermal network is given in the paper. The system represents a flow tubular reactor with recycle and one-parameter diffusion model is used to describe it. Analytical solution of a second-order homogeneous linear differential equation within the given boundary condition is carried out. Calculated and experimental concentration fields in operating Naberezhnye Chelny thermal power-station system – outdoor thermal network are compared.
Construction features, operating conditions and typical damages of station pipeline bends
E.R. Mamedov
McMamed@yandex.ru
Research Center for Power Engineering Problems of the Russian Academy of Sciences
Key words: station pipeline bends, ovality, creep, damage
Abstract
In the present work we have considered construction features, operating conditions and typical damages of station pipeline bends. The main manufacturing processes of producing bends and distinctive features of their geometry are described. The most widely used dimension types of steam pipelines and their permissible ovality are presented. We have considered the factors influencing functioning conditions of bends and limiting their operation life. The influence of the environment with the temperature above 450°С and creeping appear to be determining factors. We have given and analyzed the data on bend damages occurred within the last 5 years in a regional power system. We have defined that creep and unsatisfactory metal quality along with construction drawbacks and violations of operating conditions are the main causes of bend damage.
DEVELOPMENT AND JUSTIFICATION of IMITATION MODELING METHODOLOGY OF POWER STEAM TURBINE BLADES OPERATION LOADING
R.R. Yarullin*, B.V. Ilchenko*, A.P. Zakharov*, R.Z.Gizzatullin**
*Research Center for Power Engineering Problems of the Russian Academy of Sciences, Lobachevsky Street, 2/31, post-box 190, Kazan, 420111, Russia
**Power Engineering Company “TatEnergo”, Kazan, Russia
Key words: imitation modeling, operation loading, power steam turbine blades, finite element analysis
Abstract
In this paper we propose and justify the imitation modeling methodology of power steam turbine blades operation loading by means of tests on a servo-hydraulic system. To reproduce operation loading characteristics special experimental equipment was designed. The proposed methodology allows us to test turbine blades with fixed operating time, accumulated internal damage and surface defects.
EXPERIMENTAL RESEARCH of THE PROCESS OF WAVE FIELD FORMation IN a PERFORATED WELL
R.N.Gataullin, Ja.I.Kravtsov, E.A.Marfin
Research Center for Power Engineering Problems of the Russian Academy of Sciences
Keywords: oil, wave field, well, amplitude, frequency, casing string.
Abstract
The processes proceeding in wells with wave emitters placed in them to stimulate pressure fluctuations in a flow of the working substance forced in an oil layer are under analysis. The article is devoted to generalizing the results of an experimental research of the process of oscillation energy distribution in a perforated casing string allowing to reveal peculiarities of distribution of forced oscillations in the well and parts of a casing string of the well. Interdependence of oscillation frequency of a casing string and a quality factor of acoustic system at the given geometric features of the path and medium properties is found as well. Geometric parameters of the casing string at which oscillation energy loss is minimal when moving from the well to layer are estimated.