E.M. Gershman*, D.S. Pruglo**, A.V. Fafurin***, V.B. Yavkin****
ESTIMATION OF THE SYSTEMATIC UNCERTAINTY OF ULTRASONIC FLOWMETER IN A NONISOTHERMIC FLOW // Transactions of Academenergo. -2018. –N 2.-P.P. 7-19.
e-mail: office@ooostp.ru, GershmanEM@sibur.ru, Pruglo.DS@tmn.gazprom-neft.ru, fafurin.viktor@yandex.ru, vb.yavkin@gmail.com
*Centre “Metrology” SIBUR Ltd, **«Gasprom oil New Port » Ltd, ***FSUE Russian research institute of the flowmeter survey, ****Kazan National Research Technical University – Kazan Aviation Institute (KAI)
Keywords: ultrasonic flowmeter, nonisothermic flow, auxiliary systematic uncertainty, trajectory, profile, velocity, temperature, Mach number, Reynolds number
Abstract
When measuring the flow rate of a time-of-flight ultrasonic (US) flowmeter, an additional systematic uncertainty of the induced inhomogeneity in the velocity distribution of sound is possible. Based on the refined theory of sound propagation in an inhomogeneous flow, a mathematical model is developed for calculating the acoustic ray trajectories in a time-of-flight ultrasonic flowmeter. The analysis of the influence of various factors on the trajectories of ultrasound is carried out. It is shown that the displacement of trajectories in a nonisothermal flow increases with increasing c/c0, M and decreases with increasing Re. The displacement of trajectories causes additional systematic uncertainty. It is shown that it is necessary to introduce correction coefficients depending on the Mach number of the flux. It is established that with an increase in Re the additional systematic uncertainty decreases, and with increasing M and c/c0 increases. The determination of the velocity from different equations leads to a different uncertainty. The obtained data allow performing quantitative estimates of the allowable inhomogeneity of the temperature field.
I.А. Davletshin, N.I. Mikheev, A.A. Paereliy
convective HEAT transfer in the channel entrance region in conditions of forced flow pulsations // Transactions of Academenergo. -2018. –N 2.-P.P. 20-28.
e-mail: Davlet60@mail.ru, n.miheev@mail.ru
Federal Research Center “Kazan Scientific Center of Russian Academy of Sciences”
Keywords: flow pulsations, frequency, amplitude, heat transfer.
Abstract
The paper presents the results of an experimental study of convective heat transfer in the entrance section of a flat channel. Steady and pulsating air flow regimes have been studied experimentally. Heat transfer coefficient distributions on the channel wall have been obtained. Non-monotonous component in the heat transfer coefficient distributions has been revealed near the channel leading edge in conditions of flow pulsations.
Yu.A. Kirsanov*, A.E. Yudakhin*, D.V. Makarushkin*, A.Yu. Kirsanov**
METHOD OF HEAT TRANSFER RESEARCH IN REGENERATIVE AIR PREHEATER // Transactions of Academenergo. -2018. –N 2.-P.P. 29-44.
e-mail: kirsanov-yury@mail.ru, aejudakhin@gmail.com, atpp.danila@mail.ru, akirsanov@list.ru
*Federal Research Center “Kazan Scientific Center of Russian Academy of Sciences”
**FSSEI HE Kazan National Research Technical University named after A.N. Tupolev
Keywords: laboratory stand, regenerative air preheater, unsteady processes, measurements, temperature, heat transfer.
Abstract
The laboratory stand with a regenerative air preheater and an automated system of control and measuring of air flow and nozzle parameters is described, designed to research the heat transfer of the nozzle in the form of a parallel plates packet under unsteady conditions for periods with different duration. A method for measuring the temperature of cold and hot heat carriers is developed, taking into account the inertia of the thermocouples. According to the developed method, the thermocouple time constants were calculated and the data of direct measurements were processed in two experiments with different period durations. The graphs of time dependence of the valid temperatures of each flow at the inlet and outlet of the regenerative air preheater and the Nusselt numbers characterizing the heat transfer of a parallel plates package are presented. The obtained experimental data of the mean value of the Nusselt number for a separate period are compared with those calculated from the known criterial equations.
Aminov R. Z., Burdenkova E. Yu.
ESTIMATION OF THE INFLUENCE OF BATTERY PROPERTIES HEATED BUILDINGS ON AIR TEMPERATURES CHANGE INSIDE THE ROOMS // Transactions of Academenergo. -2018. –N 2.-P.P. 45-53.
e-mail: oepran@inbox.ru, lena.burdenkova@yandex.ru
Saratov Scientific Center of the Russian Academy of Sciences
Key words: accumulated heat, supply water, temperature disturbance, heat flow, heated room.
Abstract
Investigations have been carried out to evaluate the influence of heated buildings accumulating properties on air temperature change inside the premises, showing that the storage capacity of buildings can allow effectively manage heat release regimes from the power plant in order to attract them for regulation of the daily schedule of electrical loads. At the same time, comfort mode in heated rooms is observed, and the air temperature inside them should not go beyond the range of acceptable values. An algorithm is developed for calculating the air temperature inside the room, taking into account accumulation of heat by the material of internal partitions, floor slabs and outdoor fences after changing the temperature of the direct supply water at the entrance to the building heating system. Calculations by the proposed method have shown, that for the proposed initial data with a decrease in the temperature of the direct network water more than 30 ° C, the temperature of the indoor air becomes lower than normative and comfort conditions are violated.
N.D. Chichirova, A.A. Chichirov, A.M. Gribkov, A.A.Filimonova, A.S. Vinogradov
TECHNICAL ACTIVITIES TO ACHIEVE THE ESTABLISHED TEMPERATURE REGIME ON THE WATER RESERVOIR COOLER OF ZAINSKAYA GRES JSC “TATENERGO” // Transactions of Academenergo. -2018. –N 2.-P.P. 54-67.
e-mail: aachichirova@mail.ru
Kazan State Power Engineering University
Keywords: reservoir-cooler, Zainskaya HPS, recirculation cooling system, temperature regime, spray equipment, ejector
Abstract
Cooling reservoirs are natural or artificial reservoirs, the cooling of water in which occurs as it moves from the point of discharge to water intake. The main problem associated with the use of a cooling pond is insufficient cooling of water in the summer months. According to the available data on the reservoir-cooler of Zainskaya HPS, the average water temperature in comparison with the natural temperature of the water body in summer months exceeds the current requirements of state standard, which negatively affects the functioning of the reservoir and the operation of the power plant itself. In the article the mathematical analysis and the technical substantiation of introduction of additional ways of achievement of an optimum temperature mode in a place of a dump in heat-exchange water of Zainsk state district power station is carried out. According to the results obtained, the expected water temperature in the hottest month of the year as a result of wastewater discharge will not exceed a critical temperature maximum of 28 ° C.
Boychenko N.V.
ELASTIC AND PLASTIC STRESS INTENSITY FACTORS IN SPECIMENS OF ALUMINUM ALLOYS UNDER VARIOUS LOADING CONDITIONS AT TEMPERATURE RANGE // Transactions of Academenergo. -2018. –N 1.-P.P. 68-79.
e-mail: nataboi@ya.ru
Federal Research Center “Kazan Scientific Center of Russian Academy of Sciences”
Keywords: plastic stress intensity factor, elastic stress intensity factor, surface flaw, uniaxial tension, three-point bend, low temperature, high temperature
Abstract
This paper completes the series of works devoted to elastic and plastic stress intensity factors determination in specimens of aluminum alloys under various loading conditions in the temperature range.
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 room, high and low temperature. 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. Fundamental differences in the behavior of the elastic and plastic stress intensity factors for surface cracks in the plate are established at temperature range (20°С, 250°С, -60°С).
A.P. Zakharov, R.R. Yarullin, I.S. Ishtyryakov
Fracture resistance characteristics for heat-resisting single-crystal superalloy GS-32 under static and cyclic loading // Transactions of Academenergo. -2018. –N 1.-P.P. 80-90.
e-mail: alex.zakharov88@mail.ru, yarullin_r@mail.ru, ivan_200999@mail.ru
Federal Research Center “Kazan Scientific Center of Russian Academy of Sciences”
Keywords: Heat-resisting single-crystal superalloy GS-32, mechanical properties, low-cycle fatigue, strain loop, crack growth rate.
Abstract
The paper is concerned with experimental study of fracture resistance characteristics for heat-resisting single-crystal superalloy GS-32 under static and cyclic loading in the range of temperature. The main mechanical properties were determined under uniaxial tension and torsion. Trends of the accumulated elastic-plastic strains as a function of the stress amplitude were established. It was stated that, crack growth rate under high temperature is higher than crack growth rate under normal conditions.
O.G. Gubaeva, J.N. Zatsarinnaya, D.F. Gubaev
ANALYSIS OF 6-35 KV (MEDIUM VOLTAGE) CABLE SYSTEMS OPERATING EXPERIENCE FOR ENHANCEMENT IN EFFICIENCY OF POWER SYSTEM COMPONENTS OPERATION // Transactions of Academenergo. -2018. –N 1.-P.P. 91-97.
e-mail: mr.gubaev@mail.ru, waysubbota@gmail.com
Kazan State Power Engineering University
Keywords: math modeling, earthed neutral, isolated neutral, high-resistance resistor, AQR- arc quenching reactor, single-phase ground fault
Abstract
In order to increase the efficiency of the functioning of energy systems, it is necessary to apply a systematic approach to the analysis of the operation of its individual facilities. To develop methods for analyzing complex objects, such as energy, it is necessary to carefully analyze the initial statistical information on the operation of the elements of this system for making decisions on optimization of work, reducing damage in the objects under study. Modern requirements for reliable power supply to consumers determine the need to study the operating modes of electrical systems, leading to damage to electrical equipment and under-supply of electricity. One of the most important reasons for the emergence of such regimes is single-phase earth faults (OZZ), which turn into interphase closures. Therefore, the study of the area of existence and self-destruction of the ZPZ in 6-35 kV networks is actual and necessary for the development of measures to prevent and eliminate them. The purpose of the study is to analyze the operation of cable networks with a voltage of 6-35 kV with a different method of grounding the neutral. In the course of the research, the experience of operating distribution networks of 6-35 kV of Kyrgyzstan, 6 kV networks of the Novokuznetsk metallurgical plant and cables from cross-linked polyethylene Mosenergo was analyzed.
D.A. Kovalev*, A.A. Kovalev*, J.V. Karaeva**
PRELIMINARY INVESTIGATIONS ON ANAEROBIC BIOKONVERSION OF ORGANIC WASTE IN DIGESTER WITH HIGH PRESSURE // Transactions of Academenergo. -2018. –N 1.-P.P. 98-105.
e-mail: kovalev_da80@mail.ru, kovalev_ana@mail.ru, julieenergy@list.ru
*FSBSI «Federal scientific agroengineering center VIM»
**Federal Research Center “Kazan Scientific Center of Russian Academy of Sciences”
Keywords: anaerobic bioconversion, digester, organic loading rate, pressure.
Abstract
This article were presents the results of experimental studies of increasing the organic loading rate (OLR) in a biogas digester plant by increasing the pressure in the reaction zone. A new method for increasing the pressure in the digester by recycling biogas was proposed. As a research object, a synthetic substrate consisting of sewage sludge, mixed fodder and water was taken. The increase of pressure in the digester reaction zone from 2 kPa to 150 kPa was allowed to increase OLR in 2 times from 4 kg VS/ m3∙day to 7.95 kg VS /m3∙day. The increase of pressure during anaerobic bioconversion of the synthetic substrate was allowed to increase the degree of decomposition of organic matter by 14% (up to 83.9%).
S.S.Timofeeva, S.I. Islamova, D.V. Ermolaev
EXPERIMENTAL STUDY OF PHYSICO-CHEMICAL PEAT PROPERTIES AT PREPARATION FOR POWER GENERATION // Transactions of Academenergo. -2018. –N 1.-P.P. 106-116.
e-mail: zvezdochka198512@mail.ru, isvetulia@mail.ru, energoed@mail.ru
Federal Research Center “Kazan Scientific Center of Russian Academy of Sciences”
Keywords: valley peat, high-moor peat, fuel, properties, thermal processing, power engineering
Abstract
The purpose of this article is an experimental study of the physico-chemical properties of valley peat and high-moor peat for power generation. During of experimental studies the values of humidity, ash content, density and yield of volatiles were determined. A comparison of the samples was made using obtained data and recommendations on the use of peat resources as fuel were given. The results of the research showed that examined peat samples can be used as a feedstock for fuel production with specified properties.