bluuebunny/crossref_metadata_2025 huggingface dataset:
Electron parameters in a hollow cathode discharge plasma in He and He:H2O mixture
Authors: Andreev S N , Bernatskiy A V , Dyatko N A , Ochkin V N
Published: March 2021

The electron energy distribution functions (EEDFs) were measured in the discharge plasma in pure helium and in helium with the addition of water vapor He:H2O (2:1). The studies were carried out in the discharge gap between the rectangular hollow cathode and the mesh anode using the original probe measurement system. It was established, in particular, that the EEDF in He had pronounced maxima in the regions of ∼4 eV and ∼15 eV, while in the He:H2O mixture there was no local maximum in the high-energy region. The EEDF calculations in the local approximation for experimental conditions were performed. It turned out that the calculated distribution functions differ noticeably from the measured ones. The possible physical causes leading to the discrepancy between the measured and calculated EEDFs were discussed.
Quantitative elastic peak electron spectroscopy
Authors: Afanas’ev V P , Kaplya P S , Lobanova L G
Published: March 2021

New quantitative method of hydrogen isotopes detection in engineering materials used for fusion is introduced. The study proposes a theory of small-angle atomic particle elastic reflection from multicomponent materials. A method for interpreting Elastic Peak Electron Spectroscopy signals considering the multiple scattering effect was developed. It is shown that ignoring the multiple scattering effect results in significant errors with quantitative evaluation of Elastic Peak Electron Spectroscopy signals.
RF-heating system of helicon-type for PLM-2 plasma device: design parameters
Authors: V Tran Quang , Iachuk V A , Budaev V P , Fedorovich S D
Published: March 2021

The PLM-2 linear magnetic plasma device is for steady-state stationary hours-long plasma confinement with parameters providing the relevant fusion reactor plasma loads on materials. The machine is designed both for fundamental studies of plasma-surface interactions under high heat and particle fluxes, and as a high-heat flux facility for the tests of plasma-facing components under realistic plasma conditions. In the PLM-2 plasma device, a plasma heating ICR system will be created using a helicon antenna. Production of plasma by using helicon waves is known as helicon discharge, and the plasma produced by using the helicon discharge has a totally distinct character where the enhancement of the plasma parameters takes place at particular conditions. Helicon discharges produce higher density plasma at a comparatively lower given input power than any other RF or DC discharges, and also the plasma is least contaminated due to the presence of the antenna out-side the chamber.
Experimental investigation of thermal expansion of niobium at high temperatures
Authors: Senchenko V N , Belikov R S
Published: March 2021

Experimental study of thermal expansion of niobium by millisecond pulse heating technique was performed. Using this technique, an experimental determination of the temperature dependence of thermal expansion coefficient, electrical resistivity, enthalpy and specific heat capacity at premelting region for niobium have been carried out. The results obtained allow calculating the density of Nb in the wide range of high temperatures up to the melting point.
Determination of the thermophysical characterisitics of the Moon soil with depthed thermoprobes
Authors: Dudkin K K , Alifanov O M , Babaitsev A V
Published: March 2021

Determination of thermophysical characteristics of the lunar soil is an important scientific task. This article examined three options for penetrating thermal probe design for measuring the thermal properties of soil. A numerical simulation was carried out, and revealed distortion of temperature distribution, which can be caused by design of the thermal probe and affect the measurements, was studied,. The first scheme is a rod thermal probe, which is similar to the thermal probe used in Apollo missions. The second scheme is an improved rod thermal probe, with a detachable heater with an autonomous power source at the lower end of the rod. The third scheme is a more complicated design made by a series of autonomous heaters and temperature sensors that are fixed in a pre-drilled well and have no thermal connection. According to the calculation results, the rod thermal probe used in the Apollo missions and the thermal probe with a detachable heater showed the same level of temperature distribution distortion. The influence of the design of the split thermal probe was by 30% lower. The last type of the probe may allow to improve the accuracy of measurements of the TPC of the lunar soil.
Automated system for calculation thermophysical properties of important for power engineering substances
Authors: Vasserman A A , Malchevsky V P
Published: March 2021

Data on thermodynamic and transport properties of gases and liquids are necessary for many branches of science and technology. Such data are required in different systems of independent variables and in a wide range of values of these variables for design and study of various plants. Reliable sources of information on the properties of substances and materials are data banks and automated information systems. Recently, a large number of automated systems have been created in the world that are designed to solve various applied problems. In this work is described the system that we developed, which is designed to calculate the values of the thermophysical properties of a number of substances important for power engineering.
Research of oxygen-conducting ceramic materials for lithium chloride melt in reactors for pyrochemical processing of spent nuclear fuel
Authors: Valtseva A I , Pershin P S , Suzdaltsev A V , Zaikov Yu P
Published: March 2021

The behavior of potential ceramic materials (electrolytes conducting on oxygen ions) of electrochemical control devices of technological operations in oxide-halide melts was investigated. Based on the literature data and thermodynamic estimates for long-term tests in the LiCl, LiCl-Li2O and LiCl-Li2O-Li melts at a temperature of 650 ° C, mixtures of oxides ZrO2-Y2O3 (YSZ), ZrO2-Sc2O3 (ScSZ), ZrO2-CaO (CaSZ) and CeO2-Gd2O3 (CGO) were selected. These melt under the studies are the most widely used in a number of high-temperature electrochemical processes of obtaining metals and alloys, as well as in the developed schemes of pyrochemical processing of nuclear fuel. The stability of the samples was determined by changes in mass, appearance, elemental analysis of the melt, as well as via the scanning electron microscopy. The best stability in LiCl-Li2O melts was shown by the samples of ZrO2-Y2O3 with cubic and tetragonal structures and the samples of ZrO2-CaO. Based on the changes in the microstructure of the samples, it was concluded that the increase in the content of Li2O in the LiCl-Li2O melt accelerates the destruction of the sample mainly by the mechanism of dyeing, and the presence of lithium leads to loosening of the samples.
Thermal Coefficients of the Water–Aliphatic Alcohol Binary System
Authors: Osmanova B K , Bazaev A R , Bazaev E A
Published: March 2021

The results of thermal coefficients calculations (кT, α, β) of water–aliphatic alcohol (methanol, ethanol, 1-propanol) systems of different compositions (x=0.2, 0.5, 0.8 mole fractions of alcohol) in liquid and vapor phases, as well as at critical and supercritical regions of state parameters have been presented. The dependence of values of thermal coefficients from density temperature and composition at different states is shown. The calculations are based on the polynomial equation of state, represented by expansion of the compressibility factor into a power series of reduced density (ω=ρ/ρcr) and reduced temperature(τ=T/Tcr):Z=1+∑i=1m∑j=0niaijωi/τj. The mean percentage errors of the calculated pressure values relative to the experimental values depending on system and number of carbon atom is varied 0.6-3.3%.
Substantiation of using uranium-zirconium carbonitride as kernel for microspherical fuel
Authors: Bakhin A N , Bespechalov B N , Vishnevsky V Yu , Zaitsev D A , Kiselev D S , Kozlov V V , Kotov A Yu , Marushkin D V , Repnikov V M
Published: March 2021

The paper presents an alternative design of the micro fuel element with the use of a core made of uranium-zirconium carbonitride fuel instead of traditional uranium dioxide which has a detrimental effect on the micro fuel element operation due to oxygen. This fuel as part of the four-layer TRISO-micro fuel element creates significantly lower gas pressure under the coating, it is compatible well with a pyrocarbon coating and does not crack it. The fuel has high thermal properties and it is much less subject to the “amoeba”-effect.
Some features of the temperature-pressure dependence of the effective thermal conductivity of rocks
Authors: Emirov S N , Aliverdiev A A , Zarichnyak Yu P , Beybalaev V D , Aliev R M , Amirova A A
Published: March 2021

We have studied the behavior of the effective thermal conductivity of rocks (as natural heterogeneous materials) for the pressure range 0.1-400 MPa (initial region) and the temperature range 273-523 K. We propose a low-parametric empirical equation with great accuracy describing the effective thermal conductivity dependence, and discuss the physical meaning of its parameters.
Semi-industrial experimental studies of perspective technology for reducing harmful emissions produced by coal-fired thermal power plants
Authors: Boiko E A , Strashnikov A V , Shishmarev P V
Published: March 2021

The results of experimental studies of preliminary thermal processing of pulverized solid fuel under conditions of a semi-industrial installation for the preparation and combustion of coal with a productivity of up to 150 kg/h are presented. The studies were conducted over a wide range of pre-processing temperatures from 300 to 900 ° C, air excess from 0.2 to 0.9%, and the residence time of the carbon particles in the installation from 0.6 to 2.5 sec. The effect of preliminary thermal processing regimes on the reduction of nitrogen oxide emissions during the combustion of heat treatment products is shown experimentally. At a heat treatment temperature of 650-800 °C, emissions of nitrogen oxides are reduced by 2-3 times compared to burning of the initial fuel. An interpretation of the mechanism of the effect of preliminary thermal processing of coal on the reduction of nitrogen oxide emissions is proposed.
Application of a small deviation method in the study of the influence of external factors on gas turbine unit operation
Authors: Gubarev A Y , Kudinov A A , Eremin A V , Ziganshina S K
Published: March 2021

A correction system for energy characteristics of gas turbine units (GTU) Siemens SGT-100 and Siemens SGT-300 has been developed. It includes a set of analytical and graphical dependencies of technical and economic indicators on each of the environmental parameters (ambient air temperature ta
, relative air humidity ϕa, atmospheric pressure pat
, etc.) and other external factors at fixed values of other conditions. The dependencies are obtained by mathematical processing of experimental data under various combinations of external factors. In practice, obtaining experimental data at fixed values of external factors on the operating equipment of the power plant is difficult, since there is always a change in the environmental parameters and technological parameters of the equipment being tested. In the present paper, this problem was solved by applying a small deviation method when processing test results. The dependence between the output characteristics of the object under study and the parameters of external factors was assumed to be linear in a relatively small range of changes in the parameters under study. The article presents the study results of the influence of environmental parameters on the gas turbine units performance by a small deviation method on the example of gas turbines Siemens SGT-100 (4.7 MW) and Siemens SGT-300 (7.9 MW). The calculations were performed using the experimental inspection results of a gas turbine power plant, the main equipment of which includes gas turbines Siemens SGT-100 (4.7 MW) and Siemens SGT-300 (7.9 MW). The inspection was conducted in order to develop regulatory and technical documentation on fuel use, including energy characteristics of equipment, a correction system for deviations of external factors, and models for calculating nominal and normative specific consumption of equivalent fuel for the supply of electric energy.
Simulation of heat transfer in fire-tube and fire-tube-contact water heaters
Authors: Dolotovskii I V , Dolotovskaya N V
Published: March 2021

A mathematical model is proposed for calculating the constructive and operational characteristics of fire-tube and fire-tube-contact storage heaters used in the industrial, potable and firefighting water processing and storage units. The mathematical model includes equations for calculating heat balance, heat transfer, radiant heat transfer, and physical and chemical properties of substances. The heat transfer in fire tubes is calculated using a generalized process characteristic that is a function of structural and parametric indicators and heat engineering criteria. An example of application of the simulation software package for designing water heaters and conducting numerical experiments in order to draw up process flow diagrams accounting for variation of operational parameters and composition of fuel gas, is presented.
Nozzle design influence on the steam-driven ejector
Authors: Brezgin D V , Aronson K E
Published: March 2021

In the present paper, a series of numerical simulations of wet steam flows within ejectors distinguished by four primary nozzle contours have been carried out with the objective to evaluate the overall ejector performance. The studied primary nozzle contours are the following: a standard Laval nozzle (LAVAL); a nozzle that is designed in order to provide Constant Expansion Rate (CER); and two nozzles (MOC_SHORT, MOC_LONG) that are designed by employing axisymmetric Method of Characteristics. At first, the wet steam flow simulation throughout solely nozzles are carried out. Within the CFD simulations routines most valuable flow parameters are compared: expansion rates, boundary layer displacement and momentum thicknesses; entropy generation rate from various thermodynamic forces; thrust and liquid mass fraction across the nozzle exit plane. A comprehensive analysis of solely nozzles revealed that the CER nozzle contour is the most aerodynamically efficient design, which provides the minimum liquid mass fraction by the nozzle exit and possess the minimum entropy generation rate. The CFD results analysis of a full ejector domain revealed that an ejector with a MOC_SHORT primary nozzle contour provides the maximum performance in terms of secondary mass flow rate. At that, the secondary mass flow rate in MOC_SHORT nozzle contour case is almost 4% greater than for the CER nozzle design case.
Engineering method for calculating the operation modes of the heat supply station with the associated heat supply
Authors: Rafalskaya T A , Rudyak V Ya
Published: March 2021

The effective use of heat power in heat supply systems requires the development of new methods for central and local regulation of heat supply systems, the use of heat supply schemes with associated heat supply. The development of such technologies requires modeling and systematic calculations of variable modes of joint operation of local heat-consuming sys-tems. Currently used methods for calculating such operating modes of heat exchangers usually use constant parameters of heat exchangers. Such methods are not applicable in cases for large changes in temperatures and flow rates. Therefore, the calculation of variable modes of tied heat exchangers is usually performed by the method of successive approximations and is very time-consuming, which complicates the construction of a control system. In the present work, a fairly simple engineering technique is proposed for calculating the operating modes of heating stations of heat supply systems with associated heat supply. The basis of this technique is the use of previously derived analytical formulas that describe the change in the parameters of heat exchangers for various schemes of heating stations and temperature graphs of central regulation. The developed method allows the calculation of variable operating modes of the heat supply system without resorting to the method of successive approximations. The efficiency of the proposed methodology was tested on the operational data of the central heating station in the Kalinin district of Novosibirsk.
Performance analysis of control system tuning under inner disturbance influence by means of least square approximation to suboptimal algorithm and calculation using frequency optimality criteria
Authors: Kuzishchin V F , Merzlikina E I , Va Hoang Van
Published: March 2021

The performance of two known variants of automatic control system tuning has been analysed. The control systems contained PI and PID-regulators and disturbances influenced the process under consideration, the transfer function of the process was the second order with a transport delay typical for thermal processes. The methods used were the least square approximation to the suboptimal algorithm and the calculation method using indirect frequency optimality criteria. The PID-regulator used had a second order filter in the differentiator. The suboptimal algorithm had a second order filter with time constant T
c and correction coefficient k
τ for the regulator step response argument. Dependencies and approximation formulae for unambiguous definition of parameters T
c and k
τ using the process model parameters for the systems with PI and PID-regulators are obtained, some recommendations for determining approximation frequency range are given. When choosing these parameters the frequency oscillation index of the system is taken into account. When tuning for the indirect indexes approximating formulae determining the indirect indexes optimal values according to the process model parameters in the wide range are used. It is shown that for the system with a PID-algorithm when disturbances influence the process the tuning method using the indirect frequency indexes provides better performance of the control system. Moreover, it is more convenient for implementation in controllers, because it allows to make all the necessary calculations automatically during the one working cycle of the controller. For the system with a PI-algorithm both methods provide approximately equal performance of the control system.
All-mode Automatic Temperature Control System for Superheated Industrial Steam Boiler during Buffer Consumption of Gaseous Production Waste
Authors: Kuzishchin V F , Ismatkhodzhaev S K
Published: March 2021

The matter of the efficiency increase for an industrial steam boiler during the blast furnace gas buffer consumption is considered.. When transferring to the mode with the bigger part of the blast furnace gas (in relation to the natural gas) the superheated steam temperature significantly increases because of high blast furnace gas flows and flame movement. The ordinary range of injection change is not enough for the steam temperature stabilization behind the convective superheater second stage CSS2. There is a well-known solution of this problem for drum steam boiler E220-100 (220 t/h, 10 MPa, 540°C), for the solution a combined system is used, which, in addition to the traditional regulator of the steam temperature behind the CSS2 acting upon the injection, has a steam temperature regulator behind the CSS1 acting upon the flame position by means of turning burner air-control registers. Although the system performance was considered only for one steam flow load (100%). This paper shows dependencies for parameters of the dynamical model of the superheated steam temperature regulating channel on the load in the range of 64-100%. In order to provide the all-mode performance of the system it is offered to make automatic adjustment of the regulators parameters as the function of the steam flow according to the dependencies where the process dynamic changes are taken into consideration.
Reliability and efficiency of heat supply systems in the Leningrad region
Authors: Andreev Yu V , Grekov M A , Proskurin V M , Novikova O V
Published: March 2021

Currently, Russian heat supply system is at the stage of not just organizational, but also technological changes. Any decisions are based on determining priority criteria.

The goal of our research is to develop a set of organizational and technical solutions improving the efficiency of production and supply of heat to end consumers, taking into account the criterion that will be defined as the main one for a particular system. Current feasibility of the “generation” subsystem depends on the condition of its main generating equipment, the degree of its load, as well as the efficiency of the distribution of heat load between sources; “transportation” depends on the state of heat supply grids and the extent of their load; “consumption” depends on the state of thermal protection of buildings, losses of consumers, as well as the degree of automation of district heating substations.

The criteria may be:

1. Minimum time for the renewal of fixed assets: important in the conditions of disruption of the quality of heat supply. However, research did not confirm any significant violations[1]

2. Minimum variable costs: impact on the formation of tariffs for the population and the price for the industrial consumer;

3. Minimum grid transmission losses: for most systems, they are determined by regulations, not by actual measurements on heat supply grid sites. Not only the radius of effective heat supply and revised production technologies are important, but also the location of facilities and their capacity. However, confirmation of this version calls for implementation of a system for monitoring the state of heat supply grids, for example, based on optical fiber. This can lead to the development of distributed heat energy industry at the level of house heating substations;

4. Economic and budgetary efficiency, taking into account different project financing solutions.
Hydrogen energy and large scale hydrogen production with nuclear power plants based on high-temperature reactors
Authors: Petrunin V V , Marov I V , Kodochigov N G
Published: March 2021

At the present moment resource and ecological issues and challenges related to energy supply have become more acute. Key contradiction lies between constantly growing energy consumption and need for CO2 emission reduction. In the search of the solution hydrogen plays significant role as multi-purpose energy source and accumulator for transport, electric power, industry, distributed generation and public utility. It is expected that hydrogen energy development will benefit for the world’s energy system, environment and economy. Hydrogen may be used as pure fuel for transport and independent energy sources based on fuel elements. Global demand for hydrogen is expected to increase due to the growth of its consumption as a chemical agent in oil processing, petrochemical, chemical, metallurgic and other industries. In developed countries more than 80 % of hydrogen is derived from natural gas and petrochemicals. Large-scale hydrogen production is mainly accomplished by steam methane reforming. For natural gas saving and combustion products emission elimination steam methane reforming technology with heating from high-temperature gas cooled reactors (HTGR) is suggested. In 2018 hydrogen energy was declared as high priority area for scientific and technology development of Rosatom State Corporation. This area is integrated to the Comprehensive program project “Technology and scientific research development in nuclear energy of Russian Federation” and aims at design and demonstration of key technological solutions for nuclear hydrogen energy for large scale ecologic hydrogen production with heating from HTGR, hydrogen consumption infrastructure and integration of hydrogen energy into the economy. “Hydrogen energy” program implementation will diversify nuclear power non-electric applications.
Approaches to improving the efficiency and safety of the TPP gas economy based on internet of things technologies
Authors: Boldyrev I A , Sultanov M M , Kharitonov N V , Beokash A A , Menshikov P D
Published: March 2021

This paper describes the design features and characteristics of the “Fast-acting shut-off and control ball valve” proposed for possible replacement of the existing natural gas supply control systems of boilers and other gas-dispersing plants at the power plant. Application of FSCBV provides improvement of reliability and efficiency of gas economy of TPP due to design features, as well as application of technology of Industrial Internet of Things, which allows on the basis of statistical data to perform qualitative regulation, as well as prediction of possible failures.
Influence of indicators of quality of electric power on reliability of work of power transformer equipment of power plants and distribution networks
Authors: Strizhichenko A V , Zenina E G , Sultanov M M , Zhelyaskova O I
Published: March 2021

The lifespan of power transformers is largely determined by the state of their internal insulation, which is prone to aging during operation, now this problem is especially relevant for the operation of power transformers that have worked out a nominal life.

Direct control of internal insulation during the work is difficult due to the inaccessibility of windings for direct survey, and it is advisable to predict the residual resource for planning timely repairs. A refined model of the dependence of the speed of relative wear of the coil insulation not only on the load of the transformer, but also on the presence of asymmetry and higher harmonic components of the current is proposed
Mathematical model of the processes of restoration of power equipment in power systems by criterion of the index of technical condition
Authors: Kuryanov V N , Sultanov M M , Kuryanova E V , Skopova E M
Published: March 2021

The analysis of information about the joint use of reliability indicators and the technical condition index in assessing the state of the main electrical equipment on the example of power distribution schemes to the power system (PDSPS) of modern thermal power plants is given. The authors proposed to enter a new parameter – the index of technical condition for failure (ITCF). Technical assessment carried out by matching the actual values of the parameters of the technical state of the functional nodes with values set normative and technical documentation, as well as manufacturers, and then determine the index of the technical condition, the technical condition index to the failure of functional units and equipment for timely planning of repairs and prevent accidents. The paper presents the results of research of algorithms which allow us to form an improved approach to planning the repair program, taking into account the peculiarities of operation of the equipment.
The impact of the warm spells on reliability of the regional energy systems in Russia
Authors: Klimenko V V , Klimenko A V , Fedotova E V , Tereshin A G
Published: March 2021

The paper states the problem of the influence of extreme warm weather conditions on the Russian power system in a changing climate. The meteorological air temperature data of the warm seasons of 1945-2018 for the territory of Russia are analysed. The effects of summer warming of the Russian power systems are estimated using the relations between air temperatures and electric loads. Temperature load coefficients are calculated for four power systems of the European part of Russia. The effect on North-West, Siberian and Far East power systems was found to be negligible.
Influence of the axial compressor blade row defects on the industrial gas turbine performance
Authors: Blinov V L , Zubkov I S
Published: March 2021

This paper presents the compressor blade algorithm for predicting the defect influence on the characteristics of the stage, axial compressor or GTU as a whole. The developed model is based on the use of Bezier curves, with the control point coordinates calculated using the main geometric parameters of the airfoil, which provides highly precise geometry of both the airfoil and the blade as a whole. The paper shows some results of verification of the developed method and the selected numerical model parameters, as well as the analysis of the defect influence on the airfoil flow conditions in order to demonstrate the capabilities of the algorithm. The main results of the study were summarized and recommendations for further research were developed.
Technical and economical evaluation of a high-temperature air heater intended for integrated gasification combined cycle unit
Authors: Valtsev N V , Ryzhkov A F
Published: March 2021

In this paper the costs of creating a high-temperature air heater intended for the integrated gasification combined cycle unit developed by the authors are estimated and are compared with a steam boiler. The results can be used not only in the further development of the integrated gasification combined cycle plant under consideration, but also be interesting to specialists involved in the development of various high-temperature heat exchangers.
Experience and features of innovative training of specialists in the field of automation at the proving ground of power plant APCS
Authors: Tverskoy Yu S , Tselishchev E S , Golubev A V , Muravev I K , Nikonorov A N
Published: March 2021

Power units and power plants as automation and control objects are characterized by high dimension and redefinition, the presence of the uncertainty factor of most characteristics of a generally non-linear non-stationary system, as well as the action of random, as a rule, uncontrolled disturbances and a significant number of parameters inaccessible for direct measurement. The complexity of the technical system determines the appropriate level of requirements for the training of engineering and operational personnel in the field of modern automation and control systems, and at the same time requires the creation of adequate training tools and methodology by integrating fundamental engineering education and modern achievements in the field of information management technologies. The article summarizes the experience of 20 years of use and development of the educational and research complex «The proving ground of power plants APCS» for training specialists on the problems of modern technology of automation of energy facilities, advanced training of personnel of power plants, energy associations and engineering companies.
Mathematical support for the control system for nitrogen oxide emissions in boilers with furnaces with liquid slag removal
Authors: Parchevsky V M
Published: March 2021

When burning high-calorie low-volatile brands of coal in furnaces with liquid slag removal to achieve the standard concentration of nitrogen oxides in the outlet gases of the boiler, it is necessary to use two methods of reducing the concentration, for example, staged combustion and selective non-catalytic reduction. For optimal control of the two-stage process of successive concentration reduction, it is necessary to develop appropriate mathematical support that guarantees the maintenance of the standard concentration at any load of the boiler and minimizes the operating costs of reducing emissions. The scheme of mathematical support functioning is presented, which is an information processing system, the input of which is a signal from the steam load sensor of the boiler, and the output is a tasks for the regulators of the degree of stepwise combustion of fuel and urea supply, which ensure the optimal mode of operation of the emission control subsystem. The key issues of system development and operation are considered.
Influence of replacement of steam power plant on combined cycle gas equipment on the sanitary protection zone by noise factor
Authors: Tupov V B , Taratorin A A
Published: March 2021

Improving the safety of energy equipment of thermal power plants (TPPs) is an important task. The safety of power equipment is affected by physical influences, the most important of which is noise. Noise is one of the factors determining the size of the sanitary protection zone of thermal power plants. Article analyses the influence of TPP equipment structure on the size of sanitary protection zone (SPZ) by noise factor when replacing the equipment of traditional steam power plants with the equipment of steam and gas plants. Combined cycle gas plants (CCGT) are the most innovative technology in heat and power industry. Currently, most of exhausted steam turbine units (STU) replaced by CCGT. CCGTs are more economical and at the same time have better environmental performance, which consists in both less emission of pollutants and less noise exposure. STU supplied in standard configuration, as their efficiency slightly depends on external conditions. On contrary, the efficiency of CCGT significantly depends on climatic conditions. This dependence necessitates the implementation of individual projects, which allows at design stage of CCGT equipment to provide measures to reduce noise. Main CCGT’s noise sources are air inlet and gas outlet. At design stage, provide reducing sound pressure levels to regulatory values on border of SPZ. Data of calculations showing that increasing of STU power leads to an increase the size of the SPZ. Comparison with the results of calculations on semiempirical model and using computer of SPZ sizes at different type and structure of STU is given. Transition to supercritical steam parameters causes a jump in noise levels. Considered stepwise withdrawal of equipment and its replacement by CCGT. Described a decrease in noise levels at SPZ border. This allows performing equipment modernization in cities in conditions of developed residential building also with increase of plant capacity. Influence of climatic conditions on width of sanitary protection zones described. Shown that during the year boundaries of SPZ change at the same structure of equipment. The most correct is to specify interval in which boundaries of SPZ are located. These results allow selecting noise reduction measures more accurate.
Spectral radiate characteristics of gas phase combustion product of energetic fules
Authors: Moskalenko N I , Dodov I R , Akhmetshin A R
Published: March 2021

The results of long-term experimental studies of the spectral radiation characteristics of the gas phase of the combustion products, performed on measuring complexes of medium and high spectral resolution in the temperature range 200-2800 K, are carried out. The spectral transmission functions are parametrized by the two-parameter equivalent mass method, which makes it possible to solve radiation heat transfer problems in structurally inhomogeneous high - temperature multicomponent gas environments of the products of combustion of energy fuels of the combustion chambers of energy units to generate thermal and electrical energy. The results of modeling radiation heat transfer in combustion chambers and heat exchangers of multi - chamber furnaces with hearth multi-row burner devices and bottom feeding of solid fuel combustion products into a radiation heat exchanger from cyclone furnaces are discussed.
Physical modeling of the M-shaped boiler furnace aerodynamics
Authors: Prokhorov V B , Kirichkov V S , Chernov S L , Kaverin A A , Fomenko N E
Published: March 2021

In order to increase the thermodynamic efficiency of the Rankine cycle, in Russia, China, the USA, and EU countries, new-generation power units with advanced ultra-supercritical (A-USC) steam parameters are being developed. Using A-USC steam parameters (temperature – 700-760 °C, pressure – 35 MPa) will lead to the need to use expensive nickel steels. A single-shell design of the M-shaped boiler for burning Kuznetsk coal grade TP with solid slag removal (SSR) was proposed to reduce the total length of the main steam pipelines. A solid fuel combustion scheme with direct-flow burners, nozzles and system of vertical-horizontal tangential flames (VHTF) has been developed for this boiler, which will ensure: emissions of nitrogen oxides into the atmosphere at a level lower than standard; continuous operation of the boiler in the absence of slagging of the furnace walls and overheating of the pipe metal; a high degree of burnout of coal dust, with the provision of the standard value of the mechanical underburning of fuel; long minimum boiler load at a level not exceeding 40% of the nominal one according to the conditions of coal dust combustion stability.
Scientific bases of creation and practical application of digital acoustic model of NPP with VVER
Authors: Proskuryakov K N
Published: March 2021

Created acoustic model of nuclear reactor is presented as self-oscillating system belonging to special class of nonlinear dissipative systems capable of generating undamped oscillations with parameters that don’t depend on the initial conditions and are determined only by the properties of the system itself. In open systems, such as coolant circuit, the energy increases over time due to negative friction (negative dissipation). It is known that self-organization, in which a wave order arises spontaneously from turbulent disorder, is possible due to the exchange of energy and mass with the environment, when dissipative losses are compensated from the outside. The creation of this model combined three fundamental scientific results: the Thomson-Kelvin formula for discharge of capacitor in 1853; the properties of acoustic resonator, formulated by Helmholtz in 1869; proof by the author in 1984 of validity of the use of the method of electroacoustic analogies for study of pulsating flows of single-phase and two-phase medium in the presence of negative friction. The acoustic model of nuclear reactor has no analogues in acoustics and is designed to predict, diagnose and prevent the occurrence of unwanted self-oscillations of coolant and resonances with fluctuations of nuclear fuel and equipment in operational and emergency modes.
Heating network topology
Authors: Yegorova N V , Yakovlev A V , Nikiforov A G
Published: March 2021

The article proposes an algorithm for the topology of the heat network by generating trees of the initial redundant heat network diagram, conducting a directed search of possible system states. The technique allows you to choose the optimal configuration scheme for dead-end heating networks.
Numerical modelling of heat transfer and hydrodynamics for drop-shaped tubes bundle
Authors: Deeb R , Sidenkov D V
Published: March 2021

A numerical study has been conducted to clarify the flow and heat transfer characteristics of a cross-flow heat exchanger with drop-shaped tubes (6-rows of single/double tubes) at zero angle of attack. The study is performed for the Reynolds number Re

a
= 1.38x103 ∼ 9.36 x103.A mathematical and numerical model in software packageANSYS for numerical evaluation of heat transfer and flow field of a bundle of drop-shaped tubes, with taking into account the strain caused by different pressures inside and outside the tubeshas been developed. Correlations of the average Nusselt number Nu

av
and a friction factor f in terms of Re
D,max and Pr for the studied bundles were presented. The result of the numerical simulation indicates the pressure drop coefficient of the studied drop-shaped tube bundles is about 9.86 ∼ 10.88 times smaller than the circular one.
Combined solar collectors
Authors: Kazandzhan B I
Published: March 2021

The report considers the possibility of organizing in the MEI the production of combined solar collectors, which have become widespread in foreign countries recent years. In Russia, such collectors are not produce despite the presence in many parts of the country of favorable conditions for their use. The report presents the proposed design of combined solar collectors for production and shows the practical possibility of their manufacture and use in Russia. Application of combined solar collectors: roofs of residential and public buildings to provide them with electricity and heat. In a combined solar collector photovoltaic panel and a heat collector are located in one housing, function together, produce more energy and take up less space than if they work separately. The free area on the roof of the house in this case is doubles in comparison with separately installed photovoltaic panels and thermal solar collectors, which creates conditions for placing additional capacity on the same area and reduces the cost of installation work.
Implementation of water chemistry in fossil power plants with drum boilers and in combined cycle/HRSG plants
Authors: Petrova T I
Published: March 2021

Current water chemistry practice at fossil power plants with drum-type boilers and heat recovery steam generators includes ammonia dosing into the feedwater train and sodium phosphate or sodium hydroxide into the boiler water. The issues and impact on equipment with the use of phosphate or sodium hydroxide boiler water treatment, as well as optimum conditions for the use of these chemicals are discussed. Another operational issue of boiler unit is associated with flow-accelerated corrosion (FAC) of material, especially in the low-pressure circuit. The major reasons for boiler failures are outlined, with the data on FAC failure locations. An effect of oxygen and ammonia on boiler corrosion processes is discussed.
Determination of thermal conductivity of composites with dispersed spherical inclusions
Authors: Chernykh A A , Sharapov A I , Arzamastsev A G
Published: March 2021

The existing shortcomings of the models for determining the thermal conductivity of composite materials with dispersed spherical inclusions raise the issue of creating more advanced calculation methods. This paper proposes a model for determining the thermal conductivity of composite materials, taking into account influence of thermal resistance at the material-inclusion boundary. The analysis of numerical and theoretical calculations showed that the analytical dependence is consistent with the results of numerical modelling for relatively small values of thermal conductivity of the filler and inclusion diameter. This paper considers several models that have been recently developed and that allow calculating thermal conductivity of such materials. They are compared with the model that takes into account influence of thermal resistance of the phase boundary. Applicability intervals of the considered model for various ratios of the thermal conductivity of inclusion material and matrix material are given.
Investigation of the relationship of structural characteristics and operating regime of regenerative heat exchangers
Authors: Shatskikh Yu V , Geller Yu A
Published: March 2021

The paper presents the results of a computational study of the operating modes and design factors of a regenerative heat exchanger. The calculations were based on a mathematical model of regenerative heat transfer. It is shown that the most rational mode of heating / cooling the checkerwork is the regular mode. The regular mode is characterized by a constant local temperature head over the height of the checkerwork, and as a result, a linear distribution of the temperature of the checkerwork along the height. It is shown that it is during the implementation of the usual mode that the maximum heating temperature of the coolant and the maximum heat utilization coefficient are provided. The calculations were carried out for a hot-blast stove. In these heat exchangers, the flow rate of the cold heat-transfer agent (blast-furnace air), the temperatures of the hot and cold heat-transfer agent at the inlet to the checkerwork are constant. The range of variation of the heating/cooling time of the checkerwork for such devices is determined to ensure regular mode. It is shown that, within the framework of the regular regime, a decrease in the duration of the cooling period is accompanied by an increase in the temperature of heating the blast-furnace air, a decrease in the temperature of the flue gases, and an increase in the heat utilization coefficient. Also shown are the values of the design parameters of the checkerwork (equivalent diameter of the checkerwork channel, specific heating surface) at which the heat exchanger will operate regular regime. The calculations showed a range in which it makes sense to increase the heat- transfer coefficient of the checkerwork for a specified range of flow rates of the coolants and the time of the periods of heating and cooling. It is shown in the work that increasing the specific surface of the checkerwork heating and increasing the heat-transfer coefficient will allow one to obtain a tangible effect only in combination with a corresponding change in the operating parameters of the heat exchangers.
Study of heat exchange on the glass furnace external surface and energy economy increasing by the way of bathtub walls regulated cooling
Authors: Korovyakovskii A V , Popov S K
Published: March 2021

The duration of the work campaign and the level of fuel consumption average per work campaign determine the energy efficiency of bathtubs glass melting furnaces working with fossil fuel. This paper shows the investigation of a PHOENICS model of heat transfer on the outer surface of the furnace enclosure. An algorithm is proposed for the thermotechnical calculation of the furnace, which uses adequate ratios in finding the value of heat loss and allows to estimate the error in calculating fuel consumption. The duration of the working campaign depends on the rate of refractory fence erosion in place where it contacts with the melt. One of the ways to slow down erosion is local jet cooling of the refractory outside at the level of the melt mirror. Based on the developed PHOENICS model, it was examined the efficiency of the jet heat transfer for thermal state monitoring of the fence. The results can be used to increase the energy efficiency of glass melting furnaces.
Power -cost effectiveness of hydrogen generation using gas wastes from steel smelting
Authors: Petin S N , Vysochina T A , Grigoryev P N , Popov S K
Published: March 2021

Using the secondary energy resources will help us to reduce the specific natural gas consumption for hydrogen production. One of the most not used secondary energy resources in Russia is converter production of steel. In this production converted gas doesn’t used at all. Even more it’s burned on a flame that creates greenhouse gas (GNG) emission into the Earth atmosphere. The method of using converted gases for hydrogen production that we will look through below can help us to reduce the specific natural gas consumption with high economical efficiency. This method is based on thermochemical recuperation
Heat and mass transfer crisis in a metal hydride accumulator
Authors: Dunikov D O , Borzenko V I
Published: March 2021

Heat ttransfer is the bottleneck in design of efficient metal hydride devices. We have experimentally demonstrated heat and mass transfer crisis at hydrogen absorption in a metal hydride reactor filled with 4.69 kg of Mm0.8La0.2Ni4.1Fe0.8Al0.1. The crisis results in overheating of the MH bed and considerable slowing of absorption rate. For the case of constant hydrogen flow we have derived a simple solution for energy balance inside the reactor, which predicts the crisis.
Updating of the models for critical heat flux calculation in annular-dispersed flow
Authors: Zakharov S V , Baidakov I L
Published: March 2021

This study presents updating of two existing physical models of dryout in annular-dispersed flow regime according to the updated data of the experimental studies. Relations for critical heat flux at high mass vapour qualities, in two ranges of mass flow rates were considered. The calculation results were compared with the critical heat flux look-up tables at full range of mass flow rates. The comparing showed satisfactory agreement of results in the ranges of regime parameters 0.6 ⩽ x ⩽ 0.9; 50 ⩽ ρω ⩽ 8000 kg m-2 s-1; 0.1 ⩽ p ⩽ 20 MPa.