bluuebunny/crossref_metadata_2025 huggingface dataset:
Heat transfer enhancement by surface vortex generators. New basic mechanisms and industrial technologies
Authors: Isaev S A , Son E E , Leontiev A I , Popov I A , Nikushchenko D B
Published: March 2021

New energy effective surfaces structured by vortex generators – inclined oval-trench dimples (OTDs) – and the controlling physical mechanisms of heat transfer enhancement are explored. The narrow 7 × 1 channel with a package of one-row OTDs at Re=104.is considered. Turbulent heat transfer is studied at the channel length where the flow is steady. The OTD width is 1, its depth is 0.3, its length is 7 0.3, and its dimple step is 6. The rounding radius of the dimple edge is 0.2. The influence of the OTD inclination angle θ on the mechanisms of separated flow intensification and heat transfer enhancement in the dimple is analyzed when θ is varied from 42° to 55.5°. The optimal angle θ of order 53° is revealed, at which the relative thermal performance is close to 70% for the heated wall with a very loose packing of dimples equal to 0.235. The optimal angle θ, at which the highest thermal and hydraulic performance (THP=0.175) has been achieved, appears to be close to 47°. The maximum local value of the 4.5–5-fold relative heat transfer growth coincides with that of static pressure in the separated flow zone on the section, where relative friction grows, after it has reached its minimum value up to -4.5.
Results of calculations from a linear source with variable noise characteristics along the length
Authors: Tupov V B , Skvortsov V S , Kuzminova S A
Published: March 2021

Results of calculations from a linear source with variable noise characteristics along the length are discussing. On one hand, the issues of calculations from linear sources are well studied and the results are presented in many works. On the other hand, problems of calculations from linear sources with variable characteristics along the length have not been studied enough, and there are no results of calculations from linear sources with variable characteristics along the length. This article deals with the case when the radiated sound energy along the length of a linear source is not constant but varies along its length. Results of calculations from a linear source with variable noise characteristics along the length are given. Various factors that affect to calculation results are discussed. The results have of practical interest. For example, this concerns the calculation of noise from a gas pipeline after a gas control point (GCP). The noise from it along the length of the pipeline decreases. The results of calculations allow to make the necessary decisions to create a low-noise object and select the necessary measures for its sound attenuation.
Numerical analysis of heat transfer and hydraulic resistance during an upward turbulent flow of supercritical pressure carbon dioxide in a heated tube
Authors: Artemov V I , Kudimkin I S , Yankov G G
Published: March 2021

This paper presents the wall temperature distribution, averaged velocity, turbulent statistics, and hydraulic resistance investigated using large eddy simulation for CO2 at supercritical pressure flowing upward in a heated vertical tube for the deteriorated heat transfer regimes simulated by Bae et al. using a direct numerical simulation (DNS). Numerical simulations were performed using the “in-house” computational fluid dynamics code ANES. We discuss the reasons for certain inconsistencies in wall temperature distribution between the DNS data of Bae et al. and others, the mechanism of formation of an M-shaped profile of the averaged axial velocity, and the features of turbulent kinetic energy generation due to deformation of the averaged velocity field and buoyancy forces. We show that the return to the normal heat transfer regime after the wall temperature reaches its local peak is due to the action of buoyancy forces.
Investigation on heat transfer enhancement in a circular pipe with artificial roughness
Authors: Koroleva A P , Kuzmenkov N V , Frantcuzov M S
Published: March 2021

This paper presents a numerical analysis of convective heat transfer enhancement of transverse ribs in circular tubes. Several CFD simulations are carried out for turbulent airflow to analyze heat transfer and pressure drop provided with transverse rectangular ribs. The rib height and pitch are widely varied along with the flow Reynolds number. The effect of each parameter is examined and discussed. To accurately predict major parameters (Nusselt number, friction factor, and thermal hydraulic performance parameter) a deep neural network is developed, trained, and tested by current CFD data. The result demonstrates that artificial neural network shows better performance compared to other methods of prediction (e.g. power-law approximation) and can offer an economical and powerful approach for modeling optimal heat enhancement parameters.
Study of MHD stability limits of reactor-scale spherical tokamak
Authors: Chirkov A Yu , Lopez J E , Orozco E A , Fedyunin D E
Published: March 2021

The MHD equilibria in low aspect ratio tokamak plasma are studied. The parameters correspond to the regimes of a system of relatively large sizes, which can be considered as the concept of a reactor (or source of fusion neutrons) on deuterium fuel. The efficiency of such a system substantially depends on the limitations associated with the conditions of MHD equilibrium and stability.
A slit-based method of a high-current ion beam transversal distribution diagnostic
Authors: Golubev S V , Skalyga V A , Izotov I V , Shaposhnikov R A , Razin S V , Bokhanov A F , Kazakov M Yu , Shlepnev S P
Published: March 2021

This article presents the results of experimental studies that are part of the research aimed at the development of a point-like neutron source for fast neutron tomography. In frames of the used approach neutrons are produced in D-D fusion at the deuterium-loaded target bombarded with the focused deuterium ion beam. It was proposed to use a high-current ECR ion source to obtain the ultimate beam intensity at the target and maximize the neutron density yield. An important parameter of the neutron source is the size of the emitting region, which, in turn, is determined by the quality of the ion beam focusing. The presented work is dedicated to the development of the diagnostic system able to measure the ion beam transverse distribution. This system is based on the movable plates with orthogonal slits as an alternative to previously used scintillator-based method. The proposed system allows to determine the high-current deuterium ion beam size with an accuracy higher than 1 mm. This work presents verification of the previously obtained results of the high current focused deuterium ion beam formation by means of a slit-based method reliable in measuring beams of high intensity.
Investigation of the electric field of the plasma ball
Authors: Yunusov R F , Yunusova E R
Published: March 2021

Currently produced plasma balls have various design features and purposes. At the same time, the principle of operation of the plasma ball (PB) is described only in general terms and is of both scientific and practical interest. For the possibility of using PB in various technological areas [1-6], including in medicine, it is necessary to investigate the electric field created by this device. In this work, experiments were conducted on the study of the electric field PB: the interaction of PB with the conductor, gas-discharge light sources, and the propagation of the electromagnetic field PB over a distance. The values of the electric field strength outside PB and its dependence on distance were obtained experimentally.
High-current gas discharge with a water-solution cathode as a source of plasma flow for gasification of carbon-containing waste
Authors: Tazmeev G K , Tazmeev K K
Published: March 2021

A gas discharge with a water-solution cathode was experimentally studied in the current range 10–25 A. A bulk plasma was obtained in an extended (up to 20 cm) discharge gap. The choice of an aqueous solution of sodium chloride for use as a cathode was justified. The concentration range of an aqueous solution of sodium chloride was established to obtain a homogeneous bulk plasma. A plasma generator has been developed that allows the formation of a powerful plasma flow from the substance of a water-solution cathode. The possibility of supplying gaseous raw materials to an extended discharge gap in a plasma generator has been established. A technical system for the gasification of carbon-containing waste in two stages has been created. In the first stage, the waste was subjected to thermal degradation using an arc plasma, and in the second stage, the volatile components were converted to synthesis gas in a gas-discharge plasma with a water-solution cathode.
Probe researches of glow discharge in argon
Authors: Prokhorova E I , Platonov A A , Nazarov A I
Published: March 2021

The gas-discharge media with an inverse distribution of neutral and charged particles are of great interest for science and practical applications. A striking example of this is the laser operation. In the second half of the last century, a number of articles used to consider the possibility of forming an inverse electron distribution function (EDF), resulting in negative plasma conductivity. By analogy with the inverse population of excited states in lasers, such a medium will amplify electromagnetic waves. One of the first papers was the work [1]. The most complete theoretical study was presented in [2]. It is shown that with an inverse EDF in the low-energy part in gases with a Ramsauer minimum of the elastic scattering cross section stationary absolute negative conductivity will be formed.
Electrical resistivity of pyrolytic graphite at 2200-3200 K
Authors: Kostanovskiy A V , Zeodinov M G , Kostanovskaya M E , Pronkin A A
Published: March 2021

The electrical resistivity of UPV-1 grade pyrolytic graphite has been experimentally studied in a direction perpendicular to the deposition surface at temperatures of 2200–3200 K. It is shown that the electrical resistivity decreases by more than an order of magnitude at first heating in the temperature range from 1500 to 3200 K. The influence of the heating temperature on the electrical resistivity has been investigated in the range T = 2500-3000 K too. It is shown that the temperature dependence of the electrical resistivity coincides with the reference data at heating to T = 2700 K, and it becomes similar dependencies for a monocrystal at heating to T = 3000 K.
The problem of reproducing thermodynamic temperatures above 5000 K and generating intense infrared radiation to achieve them
Authors: Khodunkov V P , Zarichnyak Yu P
Published: March 2021

The feasibility of the operation of reproduction and transfer of a unit of thermodynamic temperature at the level of 5000 K in the metrology of temperature measurements is analyzed. A brief analysis of the current capabilities of temperature metrology is presented, the reality of reproducing high temperature and generating intense infrared radiation for its implementation is shown. The theoretical justification of the methods, schemes for their implementation, as well as brief descriptions of hardware systems are presented.
Density, specific heat capacity and viscosity of fullerene C60 solutions in tetralin
Authors: Motovoy I V , Zhelezny V P , Khliyeva O Ya , Melnik Ye Yu , Diachenko I A , Dmitriev Ye D
Published: March 2021

By combination of thermophysical and optical properties the solutions of tetralin with nanoparticles such as fullerene C60 can be considered as promising heat transfer agents for solar energy. The paper presents the results of experimental investigation for the density, viscosity and specific heat capacity of tetralin / fullerene C60 solutions. The study was performed in the temperature range 237…434 (K) and concentrations of fullerene C60 up to 1.043 (wt.%). The obtained results have shown an increase in the density and viscosity, as well as a decrease in the specific heat capacity of tetralin after adding C60. The obtained temperature dependences for the thermophysical properties of tetralin / C60 solutions are equidistant to theirs for tetralin. Obtained data on the density and viscosity were accurately fitted by a few-constant correlations for non-associated substances. The experimental data on the specific heat capacity of both tetralin and tetralin / C60 solutions indicate to significant effect of supramolecular structures in a liquid phase of aromatic hydrocarbons on this property. This effect is most significant in the temperature region close to the triple point. A new correlation for predicting the specific heat capacity of aromatic hydrocarbons containing fullerene C60 on the boiling line using a limited initial empirical data is proposed.
Characteristic features of nanofluids application in power engineering
Authors: Shatskikh Yu V , Kostanovsky A V
Published: March 2021

The problem of increasing the intensity of heat transfer is an urgent and important task. Methods of increasing the heat transfer coefficient in cooling systems of power equipment are of particular interest. Over the past two decades, a promising area of research in this area is the study of heat transfer using nanofluids. To date, domestic and foreign authors have performed a large amount of research. The scientific search is conducted in several directions: the choice of a heat-conducting material and a base fluid; the study of the influence of nanoparticle concentration and size on the intensity of heat exchange. To increase the thermal conductivity of the heat transfer agents, it is proposed to use both pure metals (Au, Cu, Fe), their oxides (CuO, Al2O3, TiO2), and carbon nanomaterials. The base fluid is mainly distilled water, mineral oil, or ethylene glycol. Almost all authors note an increase in the thermal conductivity of the nanofluid up to 40% on average compared to the base fluid. The concentration of nanoparticles in experiments does not exceed 4%. However, the studies performed often give results that significantly contradict the theory of convective heat transfer. Thus, many authors note that the heat transfer coefficient in the laminar mode of the nanofluid is greater than that of the base fluid, and the reverse is observed in the turbulent mode. A convincing explanation for this phenomenon has not yet been found. There is also no reliable data on the portable properties of materials used for the manufacture of nanofluid, in particular, there is little data on the properties of nanographene. In the article, the authors review the studies of heat transfer using nanofluid, consider the possibility of using nanotubes and multigraphen to increase the thermal conductivity of the heat transfer agent. The authors also analyze existing models of heat transfer in nanofluids.
Methodology of selecting a molecular substantiated optimal cubic equation of state
Authors: Petrik G G
Published: March 2021

The results related to the possibility of choosing the optimal cubic equations of state (ES) are presented. The study is carried out in the framework of a new model among three-term ES based on the molecular model of interacting point centers (IPC) and the well-known two-term ES of the van der Waals type. Manifestations of acting between molecules-points of attraction and repulsion forces are reflected in the structure and parameters of the ES belonging to the basic one-parameter family. The selection technique presented earlier was based on the possibility to obtain a consistent set of parameters that form the optimal equation. As a generalization of the limit variants of the ES with various manifestations of forces, a simple three-term four-parameter ES is proposed and investigated. All parameters make sense. Two relative parameters form the equation. It is shown that the known ES of Ishikawa, Chang, and Lu after the transformation become a special case of the ES of the IPC and cannot be considered as a general one. The technique was tested by calculating the critical isotherms of a number of substances, including argon, isopentane, carbon dioxide, etc. The next step should be to connect to the analysis a more finely structured control parameter.
p,ρ,T–Relations of Equimolar Ternary Water–1-Propanol–n-Hexane in Supercritical State
Authors: Bazaev A R , Bazaev E A , Osmanova B K , Dzhapparov T A G
Published: March 2021

New values of critical state parameters and p,ρ,T-relations of equimolar ternary homogeneous water–1-propanol–n-hexane (x=0.333… molar fraction or 0.1097, 0.3658, 0.5246 mass fraction of water, 1-propanol and n-hexane respectively) system in supercritical state are given. These values were carried out by using high-temperature, high-pressure, constant-volume piezometer along the isochores. The dependence of pressure from temperature and density at supercritical region (510.85–673.15 K, 255.7–615.62 kg/m3, 6.09–60 MPa) is described polynomial equation of state represented by expansion of the compressibility factor Z=pVm/RT=p/RTρminto a power series of density ω=ρ/ρcand temperature τ=T/Tc,Z=p/RTρm=1+∑i=1m∑j=0naijωi/τj;p=RTρm[1+∑i=1m∑j=0naijωi/τj], where ρm-molar density mole/m3, R=8.314–gas constant (J/mol·K).The average relative deviation of calculated values of pressure from experimental ones is not more than 0.6%.
Comparative analysis of properties of working fluids of power installations based on extended thermodynamic similarity
Authors: Chirkov A Yu , Lola D E , Luo T , Boronovskiy E G
Published: March 2021

The influence of the thermophysical properties of the working fluid on the efficiency of the working cycle is considered. Using methods of thermodynamic similarity, it is shown that one of the important factors affecting the efficiency of the thermodynamic cycle is the ratio between the slope of the saturated vapor line in the entropy–temperature diagram and the slope of vapor isobars. The influence of the composition of the working fluid and the ability to control it for maximum efficiency is discussed.
Experimental studies of hydrogen-absorbing properties of intermetallic compound LaNi4.4Fe0.3Al0. 3 for hydrogen purification
Authors: Blinov D V , Bezdudny A.A. , Dunikov D O , Kazakov A N , Kuleshov V N
Published: March 2021

Hydrogen/methane mixtures draw attention due to the idea of the injection of hydrogen into natural gas networks and biological production of biohythane by one- and two-step anaerobic fermentation/digestion methods. It is hard to extract hydrogen from dilute mixtures with methane by traditional separation processes, since hydrogen is the minor component with low partial pressure. Metal hydrides selectively absorb hydrogen and offer an opportunity to overcome the limitations of traditional separation methods. Intermetallic alloy of lowered pressure LaNi4.4Fe0.3Al0.3 was made (obtained) to use it in the extraction of hydrogen out of a mixture of gases. Hydrogen absorption properties of alloy were investigated. PCT isotherms between 313K and 353K, porosity, average particle size, specific surface area and permeability of metal hydride bed were measured, X-ray diffraction (XRD) and SEM investigation of bed structure were implemented. Experimental study of processes during the extraction of hydrogen out of binary mixture H2-CH4 (10% vol.-90% vol.) were carried out by means of continuous-flow metal hydride reactor RSP-8, filled with 1 kg of LaNi4.4Fe0.3Al0.3. Recover ratio with the mixture pressure of 1.0 MPa stood at 70%.
Interaction of Uranium-Zirconium Carbonitride Fuel Composition with Refractory Structural Materials
Authors: Zaytsev D A , Bakhin A N , Bespechalov B N , Vishnevsky V Yu , Kiselev D S , Kolesnikov E G , Kotov A Yu , Kochnov V Yu , Repnikov V M , Serikov V S
Published: March 2021

This paper uses the results of material science studies whose purpose was to investigate contact compatibility of uranium-zirconium carbonitride-based fuel pellets with the chosen refractory structural materials under the conditions of high-temperature pre-irradiation tests. Monocrystalline W-3Ta spacers with [110], [123], [112] orientations and polycrystalline W and Mo spacers served as contact pairs for the fuel pellets. The fuel and structural materials underwent annealing at various temperatures significantly exceeding 1200 °C. Duration of experiments for contact pairs with monocrystalline spacers was 80 and 300 hours, for polycrys-talline materials the exposure was 50, 100 and 150 hours. High stability of microstructure and chemistry of the U,Zr(C,N)-based composition was observed throughout the entire temperature-time diapason of the tests. No formation of intermediate phases capable of impairing air-tightness and operability of the cladding materials have been found in the interface zone. As a result of the studies performed, it has been found that orientation of W-3Ta monocrystals has no impact on the diffusion rate. Depth of uranium atoms penetration into monocrystalline samples didn’t exceed 15μm in the entire temperature-time diapason. For polycrystalline materials this value was 40 and 350 for W and Mo respectively.
Preparation for reactor tests of uranium-zirconium carbonitride fuel
Authors: Bakhin A N , Bazyuk S S , Vishnevsky V Yu , Repnikov V M , Kotov A Yu , Kiselev D S , Zaitsev D A , Bespechalov B N , Titkova E M , Stoykov K V , Garmay Yu V
Published: March 2021

Uranium-zirconium carbonitride based fuel (CNF) is a consequential modification of UN retaining almost all the advantages of UN. This fuel boasts rather high uranium content and high heat conductivity. Uranium-zirconium carbonitride fuel is safer due to its higher tolerance (inertia) to accident processes development. Thanks to its properties, the CNF is an attractive candidate material for using in reactors of various types. The main drawback of UZr(CN) is insufficient amount of data regarding its performance and behavior under irradiation, especially at high burn-ups. To address this problem, preparations are currently underway to perform a reactor experiment with the goal to study the properties of the CNF after reaching ≈ 7% burn-up. The parameters of the reactor experiment are as follows: cladding temperature not exceeding 800 K, power density not exceeding 750 W/cm3. For the purposes of reactor testing of the CNF pellets at high burn-up, an experimental capsule installed into the irradiating device has been developed. To verify the choice of designs of both the experimental capsule and the irradiating device thermophysical calculations were made and a programme of pre-irradiation experiments was completed. This paper elaborates on the results of the calculations demonstrating that the reactor tests fit the set goals and objectives.
Application of the object-oriented approach to intelligent DCS data flow optimization
Authors: Arakelian E K , Evseev K V
Published: March 2021

This paper is on the thermal power plant intelligent DCS data flows optimization for increase of control performance and technical and economic efficiency. The proposed object-oriented approach for control system data flow interpretation allows building a hierarchical directed structure to trace value transformations through measuring and informational channels. The problem of parameter influence evaluation on the technical and economic efficiency estimation using the described approach is set.
Spectral analysis of gas-dynamic processes in the exhaust system of piston engine (82/71)
Authors: Plotnikov L V , Zhilkin B P , Osipov L E
Published: March 2021

Batch machines are actively used in industry and energy. Internal combustion engines are a prime example of such machines. A feature of the operation of engines is that a certain amount of the working fluid is supplied to the working chamber, and upon completion of the process, the combustion products are removed from the chamber. Therefore, the aeromechanics of pulsating gas flows in the exhaust system significantly determines the efficiency of the engine. A distinctive feature of the processes in the exhaust system is their high dynamics (high-frequency pulsations due to the operation of valves with external disturbance from the turbine blades of the turbocharger). The article describes laboratory equipment (piston engine model), measuring system (main sensors and determined physical quantities) and data processing methods (spectral analysis). The boundary conditions during experimental studies are described. The aeromechanical characteristics of non-stationary flows in the exhaust system of the engine with and without a turbocharger are compared. Qualitative and quantitative differences in aeromechanics and thermophysics of processes in exhaust systems of various configurations are shown. A method for aeromechanical improvement of the exhaust system by creating an ejection effect is proposed. It was found that the ejection effect in the exhaust system of the engine leads to stabilization of the flow, an increase in air consumption by 6-12% and an improvement in reliability indicators by 1.11-1.74%.
Reducing power consumption of local exhaust ventilation systems
Authors: Logachev K I , Ziganshin A M , Averkova O A , Gol’tsov A B
Published: March 2021

Local exhaust ventilation systems have become the most popular choice for capturing and containing releases of gas-borne dust contaminants in various fields of human activities. Energy conservation techniques have to be developed for these systems while ensuring that their contaminant capture efficiency is not compromised. This study summarizes our developments in the field of energy-saving techniques relying on the properties of detached, twisted and recycled flows of dust-laden air.
The first operation results of the gas turbine unit M701F4 as a part of CCP-410 of the Krasnodar TPP after major overhaul
Authors: Shaposhnikov V V , Batko D N , Mihalko Ya O
Published: March 2021

The article contains the reconstruction results of the M701F4 gas turbine unit of the Krasnodar TPP, where it has been in operation since 2011. In May 2019, it was overhauled with the replacement of the gas turbine working blades. In the first two rows, the blades of a new design were used. This allowed reducing the air flow for cooling and forcing the combustion chamber. For research we obtained archival indicators of a standard automation system. They were selected for the periods of operation, which lasted from June 2018 until the moment of major repairs (May 2019) and from June 2019 to January 2020. Data processing was carried out in accordance with State Standard R 55798-2013 (ISO 2314: 2009). The study showed that the reconstruction led to an increase in maximum capacity in the entire range of outdoor temperatures. Under normal conditions and standard air temperature at the compressor inlet equal to +15 °C, there is an increase by 14.4 MW or by 4.6%. The temperature of the combustion products also increased, the increase was about 15 °C in the range of outdoor temperatures from +5.6 to + 20.0 °C. The change in the consumption of combustion products is insignificant. We also estimated an increase in the efficiency of electricity generation. It is at the level of 0.5%.
Investigation of the regulatory range expansion at Krasnodar combined heat and power plant due to the partial displacement of regenerative extractions of the K-150-130 unit by steam from the backpressure turbine
Authors: Shaposhnikov V V , Mihalko Ya O , Batko D N
Published: March 2021

The article describes a new way to increase the technical maximum load of Krasnodar CHPP. It involves the joint operation of block part turbo generators and additionally installed backpressure turbine with the displacement of steam extraction to high pressure regenerative heaters. We provided a detailed overview of the power plant equipment. We calculated the effectiveness of joint operation and shutdown of the high pressure feed water heater (HPFH) 1, 2. It showed that when implementing the proposed technical solution, the power increase in the technical maximum mode for each unit amounted to 7.8 MW. The total increase in the power plant is 43.6 MW. The joint operation scheme allows to increase the technical maximum of the power plant with higher energy efficiency: the specific consumption of reference fuel for electricity generation is 4 g r.f./kW*h, lower than when the HPFH 1, 2 is turned off. The economic effect of the applied solution was estimated for Krasnodar CHPP conditions. It was shown that the annual increase in net profit amounted to 33.7 million rubles, and the payback period of investments is 4.7 years.
Assessment of the possibility of developing isokinetic devices for water and steam sampling in chemical control systems of TPP and NPP
Authors: Yegoshina O V , Zvonareva S K
Published: March 2021

The proposed work is intended for operational staff and employees of project organizations. The possibility of modernization of sampling devices for superheated steam sampling in automatic chemical control systems at thermal and nuclear power plants is considered. The results of calculating the flow rate and the inlet diameter of the superheated steam sampling device are presented. A nomogram has been developed to determine the required diameter of the inlet of the sampling device. Two cases were modeled of sampling in the software package Ansys, confirming the need to modernize the design of standard devices for steam sampling.
Application of the signal speed change limiting method for increasing the indications credibility on the example of hydraulic shock absorber monitoring system
Authors: Kolchev K , Shilov A , Chernaev A , Galiev I
Published: March 2021

This article is devoted to the problem of unreliable indications in a system with sensors operating in harsh environmental conditions. To increase the indications credibility, an algorithm based on the signal speed change limiting method is proposed when calculating the average speed value using the simple moving average formula. The result of the algorithm obtained by modeling the algorithm in a software environment on a sample of linear displacement sensor indications obtained from the hydraulic shock absorbers monitoring system of the current NPP power unit is also presented.
Evaluating the Effect from Shifting a Small-Scale Cogeneration Power Facility to Operate as a Trigeneration Plant
Authors: Klimenko A V , Agababov V S , Petin S N , Koryagin A V , Korshikova A A
Published: March 2021

The article considers the power supply system of a really existing social facility located in the central part of Russia, which comprises an ice palace, a swimming pool, a hotel and office complex, and a business center. At present, the facility receives power according to a cogeneration arrangement: it takes electricity and heat from a power park a centralized manner. Refrigeration and air conditioning demands are met by using vapor compression heat transformers installed in the social facility rooms. A trigeneration power supply arrangement is proposed, which involves combined generation of electricity, heat, and cold with supplying them to the social facility rooms in a centralized manner. The thermodynamic advantage of the trigeneration power supply arrangement for the considered social facility is demonstrated.
Study of the energy efficiency of wood pellets and poplar chips
Authors: Lyubov V K , Popov A N , Popova E I
Published: March 2021

Poplar is the most common type of fast-growing tree species of great economic and industrial importance. Therefore, determining the effectiveness of its energy use is an important task. A study of the operational efficiency of the Firematic 60 boiler when working on poplar chips, as well as pine wood pellets with a diameter of 6 mm and spruce wood pellets with a diameter of 8 mm was carried out. The elemental composition of burned fuels and residues was studied using an EDX-8000 X-ray fluorescence spectrometer and a Euro EA-3000 analyzer. The components of the heat balance and emission of harmful substances were determined. The emissions of particulate matter and the content of soot particles were studied. The shape and composition of soot particles were determined using a Zeiss SIGMA VP electronic scanning microscope. An energy examination showed that the boiler provides high technical and economic indicators and minimal emissions of harmful substances into the environment when burning wood pellets and poplar chips.
Solid fuel combustion processes modelling in the furnace in terms of the boiler K-50-14-250
Authors: Prokhorov V B , Fomenko M V , Fomenko N E
Published: March 2021

The paper presents the numerical simulation results of furnace of the boiler K-50-14-250 for three operation modes with computational fluid dynamics software ANSYS Fluent. The boiler is located at industrial heating boiler house in Tashtagol town. The selection of models for the boiler furnace operation simulation is given. A study of simulation results independence on the mesh size was conducted, based on which a computational mesh was selected for further research. The numerical simulation results of three modes furnace operation were compared with the results of the field tests (flue gas temperature at the furnace outlet, combustible losses, heat absorption of the furnace heating surfaces, the nitrogen oxides concentration in the exhaust gases at excess air ratio α = 1.4). Besides, a slagging process numerical simulation of the furnace waterwalls performed. The numerical simulation results of the near nominal load furnace operation are compared with the results of physical isothermal modelling by matching the streamlines from the burners and air nozzles of the boiler. The paper summary is the verification of numerical models of the solid fuel combustion in the furnace, in terms of the boiler K-50-14-250.
Analysis of the results of thermophysical experiments with multi-rod bundles. Elaboration of the SCP thermalhydraulic test facility design
Authors: Zubkov A G , Zorin V M , Anikeev A V , Silin V A , Semchenkov Ju M , Oleksyuk D A
Published: March 2021

The present report is devoted to the analysis of the thermophysical properties of supercritical water in the cores of supercritical water-cooled reactors (SCWR) and results of the experiments with multi-rod bundles cooled with supercritical fluid (mainly – water) flows carried out in different countries. The most important results and specific heat transfer regimes observed in the experiments were summarized. On the basis of the experimental data analysis the design of a thermophysical test facility for full-scale experiments for the determination of the heat and mass exchange regimes and supercritical water hydraulic parameters in multi-rod bundles was elaborated. The need for the experimental data for the proper description of the said processes was stated, and the importance of obtaining them was underlined. The list of the controlled parameters and experiments was created.
On the matter of the development of automatic chemical control system for thermal power plants using modern hardware and software
Authors: Dolbikova N S , Merzlikina E I , Nikitina N S
Published: March 2021

This article considers development of modern chemical monitoring systems using modern hardware and software. Application of these means gives a lot of possibilities for improving reliability of the chemical monitoring systems, main power plant equipment and water chemistry maintenance. An information system is described, the system contains a decision support module, that allows to identify faulty chemical measuring instruments, inform the plant staff about the scheduled maintenance operations and identify the reason of a water chemistry upset. A model of such a system is developed using Tehnopribor and Owen hardware and CODESYS 2 and Trace Mode 6 software.
Influence of wood additives on pyrolysis products composition of mixed fuels based on 3B grade lignite
Authors: Kuznetsov G V , Tolokolnikov A A , Cherednik I V , Yankovsky S A
Published: March 2021

Experimental analysis of the influence of wood biomass on the composition of pyrolysis products of mixtures based on crushed coal (“Lignite” (3B)) and fine wood (lumber sawing waste) has been performed. Ash residue composition of the main components of fuels and mixtures based on them has been determined experimentally using X-Supreme 8000 element analysis device. Fuel mixture samples were used with a percentage of coal / wood – 100 % / 0 %, 90 % / 10 %, 75 % / 25 %, 50 % / 50 by weight. The experiments have been performed in an inert gas (Argon) environment at temperatures of 400 °C, 600 °C, and 800 °C. It has been established that during pyrolysis of two-component fuels based on 3B grade coal and dispersed wood biomass, there is growth of calcium and aluminum sulfates in the solid products of thermal decomposition of such mixtures (ash) due to a complex of reactions between pyrolysis products of coals and wood when the concentration of the wood component in the mixture changes from 10% to 50 %. Results of experimental studies allow substantiating previously formulated hypothesis about the mechanism of sequestering of sulfur oxides formed during coal pyrolysis as a result of interaction with gaseous products of thermal decomposition of wood and solid products of coal pyrolysis.
Problems and prospects of creating an environmentally friendly WtE plant
Authors: Dudolin A A , Efremov A N
Published: March 2021

The main stages in choosing the optimal technology for thermal treatment of MSW (municipal solid wastes) at the stage of feasibility study are discussed. The analysis of the influence of the fuel component on the structure of the WTE plant is carried out. Recommendations have been developed for choosing the optimal energy structure of a WTE plant, ash and slag management schemes, and thermal utilization technologies that are most suitable for the location of the facility. A study was conducted on the influence of the selected structure of the energy complex on the decision to choose a gas treatment system. A comparison of criteria for choosing the structure of the energy complex at the MSW in comparison with the energy thermal power plant (TPP) is made.

Due to the economic and environmental problems that appear during the construction of WTE plants, when it comes to waste scheme for cities and regions, it is recommended to use a scheme with the maximum use of secondary raw materials from waste and thermal treatment only of residues that are not subject to recycling, from which the fractions containing the largest amount of pollutants (RDF fuel) are extracted. The technology using deep recovery of secondary raw materials will simplify the structure of WTE plant, reduce capital and operating costs, and most importantly reduce emissions of harmful substances into the atmosphere with flue gases, ash and slag.
Efficient operation and reliability issues in operation of mini-CHP
Authors: Polei A K , Shtym K A
Published: March 2021

The article presents practical data on the operation of cogeneration mini-CHP plants in the energy sector of the Far East using imported low-power GTU as the main generating equipment. This type of power station is an example of decentralized distributed energy that has become widespread in Western Europe, and is first introduced in the energy sector of the Far East. Mini-thermal power plants based on GTU with the use of cogeneration have a great economic potential for application in the energy sector of the Far East, taking into account the positive and negative sides indicated in this article.
High efficiency steam-gas mixture condenser
Authors: Milman O O , Yankov G G , Krylov V S , Ptahin A V
Published: March 2021

The process of development of steam condenser for steam-gas mixture has been described. The construction is based on idea to maintain a constant steam-gas mixture speed along the steam condensation channel. The shape of the channel with constant speed is described. To research the heat-mass transfer of gas- steam mixture the test plant with tubes dissected by thermocouples, have been realized. In the process of testing there where changes of gas- steam mixture speed, pressure and air concentration from 0% to 18%. The experimental results have been summarized by dimensionless equation. The pressure drop and increase of air concentration also contributes to the decrease in a saturation temperature. So there Is optimal speed when the surface area of channel in condenser will be minimal. The optimal speed value is about 30 – 50 m/s. The research results are implemented in the experimental model of high-efficiency condenser. The heat transfer coefficient in this model is equal about 4500 – 2700 W/(m2K), if the air concentration at inlet is 0–8 %. The design of high-efficiency condenser for gas-steam turbine plant 25 MW capacity and condenser with vertical tubes have been presented.
The effect of mixtures of neutralizing amines on the dynamic exchange capacity of strong acid cationite KU-2-8
Authors: Moryganova Y A , Orlov K A , Motyzko T E
Published: March 2021

The dependence of the ion exchange capacity of strong acid cationite KU-2-8 on the concentration and structure of low-molecular organic compounds containing an amino group has been experimentally established. The mutual influence of neutralizing amines that are part of complex reagents that reduce the value of the exchange capacity of cations during operation of thermal power plant was revealed.
Methods for calculating the heat capacity of decafluorobutane in a liquid
Authors: Granchenko P P , Kuznetsov K I , Sukhikh A A , Skorodumov S V , Basidov R I
Published: March 2021

This work presents a comparison of the values of isochoric and isobaric heat capacities in a liquid in the range of parameters from 20°C to 140°C and pressures from 2 MPa to 10 MPa, obtained by two different methods. Under one of the proposed methods isobaric and isochoric heat capacities are obtained within joint thermal (pυT-dependence) and acoustic (speed of sound) measurements, the other method represents heat capacity values are obtained from a unified equation of state presented by the authors earlier based on the results of experimental and computational studies. New density measurements on 7 isotherms in the liquid and supercritical areas of state in the temperature range from 5°C to 141°C and pressure from 1.6 MPa to 10.9 MPa are presented. Estimation of the calculated based on experimental data for the isochoric heat capacity is ± 5%. The discrepancy between the calculated values of the heat capacity by both methods in the entire range of the studied temperatures reaches 30%, which is explained by the lack of experimental data on the heat capacity in the known literature.
Numerical modelling method of heat exchange in heat accumulators with many phases and free phase boundaries movement
Authors: Purdin M S
Published: March 2021

A correct implicit unconditionally stable numerical method for modelling heat transfer in heat accumulators with many phases and free phase boundaries movement of has been developed and presented. The stability of the implicit numerical scheme for approximating the energy equation is studied. As an example, a hardening process of zinc casting with a thickness of 10 cm was considered and compared with the results of calculations by another author.
The impact of anode gas diffusion layer structure on fuel cell performance
Authors: Fedotov A A , Tarasenko A B , Karanova D A
Published: March 2021

The gas diffusion layer (GDL) plays an important role in the operation of fuel cells with a proton exchange membrane (PEMFC). GDL is commonly used on three possible types of carbon fiber-con backing: carbon fabric, non-woven material, carbon paper. All three types have different properties, such as gas permeability, mechanical strength, electrical resistance, hydrophilicity and price. Paper is much cheaper than non-woven material, and replacing even one electrode could make a fuel cell cheaper. But replacement makes sense only if the same efficiency is maintained. In this work, two types of GDL as an anode in PEMFC were compared. As a result of the comparison, current-voltage and power characteristics were obtained.
The parameters of the off-grid power system with a biomass gasifier engine for the autonomous power supply of forest harvesters
Authors: Anisimov P N , Medyakov A A
Published: March 2021

The paper analyses the results of the simulation modelling of autonomous power supply system of forest electric drive harvesters. MATLAB with the use of dynamic modelling Simulink tools was employed for the simulation modelling. The modelled system incorporates gasifier for solid fuelwood, a heat engine, an electric generator, a battery, and electric drive engines for the mechanisms of a mobile wood chipper. The authors determined that the minimum 12 A h Battery is required to ensure the uninterrupted operation of an off-grid power system with a gasifier, a 300 kW heat engine and a 200 kW engine wood chipper. The model allows for measuring the system performance indicators in various operating modes. The specific consumption of fuelwood was 2.217 kg/kW h in the specified mode.
Enterprise technical policy as a tool for improving energy efficiency
Authors: Krylenko E E
Published: March 2021

The paper presents the development of the main provisions of technical policy, aimed at improving efficiency in the use of basic production assets of the enterprises of power generating set. Technical policy, as one of the main strategic documents of the enterprise, can be considered as a tool to improve energy efficiency.
The Manufacturing Process of Recycled Polymer Composites reinforced with Natural Fibers – A Systematic Literature Review
Authors: Govinda  , Widiastuti Indah
Published: March 2021

In the light of growing global awareness in environmental sustainability, it is essential to employ more “environmentally friendly technology” which preserve natural resources. In the past decade, natural fiber composites with thermoplastic and thermoset polymers have been applied by several industrial sectors in various parts of the world. Natural fibers such as kenaf, hemp, sisal, abaca, and sugar palm have been widely used because they provide several advantages such as low cost, environmentally friendly, and reducing dependence on the use of materials that cannot be recycled. The use of recycled material for the development of natural fibre reinforced polymer (NFRP) has seeking current attention. This article reviewed several literatures on the manufacturing process of recycled polymer in NFRP material. The five-step systematic literature review (SLR) was chosen as the approach in reviewing the literature. The analysis of the selected articles revealed that a successful process for making recycled natural fiber reinforced polymers begun by appropriate treatment of natural fibers. Treatment of natural fibers using alkaline treatment (sodium hydroxide (NaOH) and silane treatment is the most influential factor in the success of the process of making recycled polymer composites reinforced with natural fibers. This study implies a new manufacturing trend for natural based fibre composites in recycled polymer matrix.
Effect of Adding of Pitch on the Darrieus Blade Against the Cut In Speed of the Savonius Type S - Darrieus Type H Hybrid Turbine
Authors: Ibadi Husni , Sangidzun Ahmad , Wijayanto Danar Susilo , Saputro Herman , Soenarto  , Triyono M Bruri
Published: March 2021

This research was aimed to analyze the effect of adding pitch angle to the performance of a Savonius Hybrid Type S-Darrieus Type H-Rotor wind turbine with variations in wind speed. This research used an experimental method with variations in pitch angle and wind speed. Variables taken in this study are wind speed, pitch angle addition, and wind turbine cutting speed. Variations in the addition of pitch angles are 0°, 5°, 10°, 15 °, 20°, 25°, 30°. The results showed that the addition of pitch angles to the blade influenced the cut in speed. The highest cut in speed is 4.2 m/s at the addition of pitch 0° while the lowest cut in speed is at 3.8 m/s at the addition of a 30° pitch angle.