bluuebunny/crossref_metadata_2025 huggingface dataset:
Plasma technology for creating highly porous titanium materials for biocompatibility testing
Authors: Budaev V P , Fedorovich S D , Martynenko Yu V , Egorikhina M N , Karpov A V , Gubkin M K , Budaeva M V , Lazukin A V , Marchenkov A Yu
Published: March 2021

Titanium samples have been processed with plasma in PLM plasma device to obtain a highly porous nanostructured surface. Post-mortem analysis scanning electron microscopy of the samples has approved the formation of a porous stochastic nanostructured surface with the size of the pores and structure elements less than 500 nm. Such material samples will be used for biocompatibility testing using scaffold technology in support of the biomedical application of new highly porous materials.
A new method for measuring the spectral emissivity of heated bodies
Authors: Khodunkov V P , Zarichnyak Yu P
Published: March 2021

A new spectral method for measuring the emissivity of solids at high temperatures is considered. The method is based on a linear dependence of the spectral energy brightness of a body on wavelength in a narrow spectral range. The theoretical basis and the results of experimental verification of the method are presented.
Thermal conductivity prediction of Trans-1-Chloro-3,3,3-Trifluoropropene (R1233zd (E))
Authors: Tsvetkov O B , Mitropov V V , Prostorova A O , laptev Yu A
Published: March 2021

R1233zd(E), trans-1-chloro-3,3,3,-trifluoropropene, is a fluorinated propene isomer which may be considered as an alternative working fluids in the field of heat pump and organic Rankine cycle. R1233zd(E) has a much lower GWP than hydrochlorofluorocarbons (HCFC) and their mixtures. In this paper an extension of a previously developed predictive methods for thermal conductivity to a new family of organic compounds, namely R1233zd(E) is considered. A study of the correlation of thermal conductivities of polyatomic gases in the limit of zero density of R1233zd(E) is presented. A theorically correlation scheme based on the formalism Mason-Monchik-Parker theory has been examined and found to be useful for prediction of thermal conductivity data of dilute gas. An attempt is made in this work on the theoretical approach by Predvoditelev, Vargaftik and Filippov proposed for prediction of thermal conductivity for liquid state. The scheme has been tested against the limited amount of experimental data available and shown to be capable of reproducing the thermal conductivities to within few percent. This predicting approach appears promising as an assist in the judgments in the area of this new generation of working fluids data studies.
Phase Transitions and Critical Properties of Binary Systems Consisting of Water, Alcohols, and Hydrocarbons
Authors: Bazaev E A , Bazaev A R , Osmanova B K , Dzhapparov T A G
Published: March 2021

By the method of constant volume piezometer values of p,T - and p,ρ,T-relations of binary homogeneous systems consist of water, alcohol (methanol, ethanol, 1-propanol) and hydrocarbon (n-pentane, n-hexane, n-heptane, n-octane) with the concentration of the second component x=0.2, 0.5, 0.8, 0.9 mole fraction were obtained at subcritical, nearcritical and supercritical regions of stare parameters. Using isochoric p-T break point technique the values of the phase transition parameters ps,ρs,Ts(lg⇄l and lg ⇄g l–liquid, g–gas) were determined. Using grapho-analytical method combining with the scaling behavior the critical parameters (pc,ρc,Tc) are evaluated. The dependence of pressure from temperature, density and composition along the phase coexistence curve is described by three parameter polynomial represented by expansion of the compressibility factor Zs=psVms/RTs=ps/RTsρmsinto a power series of density ω=ρs/ρcand temperature τ=Ts/Tc, and concentration x.Zs=ps/RTsρms=1+∑i=1m∑j=0n∑k=0saijkωi/τj,ps=RTsρms[1+∑i=1m∑j=0n∑k=0saijkωi/τj]. The average relative deviation of calculated values of pressure from experimental ones is varied 0.1–0.5 % depending on the studied system and its component composition. The dependence of temperature from density along the liquid↔gas phase coexistence curve is described by equations: far from critical points ρl,g= ρc(1±B0τβ0+ B1τβ1± B2τβ2+ …), and in the symmetrical part of equilibrium curve (ρl- ρg)/2ρc= B0τβ0+ B2τβ2+ B4τβ4+ … Average relative error is 1.1-1.6%.
Expert diagnostics of slagging of heating surfaces of coal-fired boilers
Authors: Zagorodniy I V , Boiko E A , Ermak D E
Published: March 2021

The article is devoted to the development of a system for the technical diagnostics of slagging processes and contamination of the heating surfaces of coal-fired steam boilers, which operates online based on the interpretation of the standard information of ACS TP and scientifically proved algorithms for processing balanced equations to evaluate the thermal efficiency of radiation, semi-radiation and convective heating surfaces. The system is implemented at the level of algorithmic data and software in the programming language C #, which is built into the current system of the automatic control system of the boiler unit. The project aims to increase the reliability, efficiency and economy of steam boilers by quick maintenance of heating surfaces in an operational clean state, ensuring optimal performance characteristics of the main technological equipment. This system is at the trial operation stage at the BKZ-500-140 boiler unit, station No. 6 of JSC Krasnoyarsk CHP-2. The expected effect of the introduction of this boiler due to the reduction of the blowing cycles and the decrease in the slagging intensity will amount up to 2.175 million rubles annually per one boiler unit.
Development of the system for preparing, maintaining and qualification improving of operational personnel of energy organizations
Authors: Okhotin V V
Published: March 2021

This article discusses the structure of the system for preparing, maintaining and qualification improving of operational personnel (SPM and QI) of energy organizations and the main results of the work for its development with the participation of the author in the National Research University “MPEI” and energy organizations, in terms of legal support, organizational support, technical and mathematical support, software and methodological support for this system.
Efficiency Assessment of Hydrogen Production Systems under Fatigue Wear Conditions
Authors: Bairamov A A
Published: March 2021

The article aims to assess the efficiency of hydrogen facility based on the night-time off-peak energy produced by the nuclear power plant (NPP) in comparison with the pumped storage power plant (PSPP) under conditions of fatigue wear of the master equipment. The relevance of hydrogen facility coupled to NPP units is evaluated. Evidenced is provided for the necessity of assessment and accounting of fatigue wear of the master equipment in the hydrogen facility. A new methodology for assessing the working resource of the master equipment has been worked out with account for the turbine rotor using of a condensation type turbine C-1000-60 / 1500 example under fatigue wear conditions. This methodology is used to determine the maximum number of cycles prior to fracture in the critical elements of the master equipment depending on the cyclic loads per day. A nomograph has been designed to estimate the prime cost of on-peak energy of the hydrogen system considering fatigue wear of the basic facility. Competitive advantages of the hydrogen complex and the PSPP is estimated based on the net present value criterion (NPV). It is shown that the hydrogen system can compete with the PSPP under its relative capital investments at about $ 660 / kW. The PSPP versions under the relative capital investments over $ 660 / kW lose their competitiveness compared to hydrogen complex.
Trigeneration units on carbon dioxide with two-time overheating with installation of turbo detainder and recovery boiler
Authors: Ovsyannik A V , Kovalchuk P A , Arshukov A I , Klyuchinsky V P
Published: March 2021

The schemes of a carbon dioxide trigeneration plant using secondary energy resources in the form of products of combustion or flue gases and a combined cycle gas turbine unit (CCGT) with a recovery boiler, which simultaneously produce electricity, heat and cold for centralized and decentralized supply of consumers, are presented. In addition, the production of liquid and gaseous carbon dioxide is possible. The main elements of the plants are a heating unit, a gas turbine unit with a recovery boiler, a turboexpander unit and a carbon dioxide unit for the production of cold, liquid and gaseous carbon dioxide. A thermodynamic calculation and a brief exergy analysis of the plants were carried out.
Reducing the negative environmental impact of thermal power plants by optimization of the operational modes of hydropower plants in the power grids
Authors: Aleksandrovskii A Yu , Klimenko V V , Tereshin A G , Volkov D M , Soldatkin A Yu
Published: March 2021

The paper analyses the current state of energy and the environment in the regions where the Russian largest HPP cascades are located – Volga region and Siberia. The effect of various limitations on HPP operations (power systems and water users restrictions, deviations from design operation characteristics) and resulting excess load at TPP are estimated. The environmental impact assessment (reducing emissions of pollutants and greenhouse gases in energy systems assuming maximum hydropower generation) is conducted. It is shown, that actions to increase HPPs usage efficiency (construction of new transmission lines, raising water reservoir level to level established by HPP design, enhancement of basic rules of water resources use) can save 3 million tce of fossil fuel annually and decrease emissions of air pollutants by 50 thousand tons and of carbon dioxide by 6 million tons annually
Developing SupercomputerTwins Of NuclearPowerPlants ForVarious Applications With The Use Of Russian 3D Numerical Analysis Codes
Authors: Bolnov V A , Bolshukhin M A , Budnikov A V , Dmitriev S M , Zotova M V , Zotov I S , Petrunin V V , Sveshnikov D N , Romanov R I
Published: March 2021

The article describes the technology of the supercomputer twin of a nuclear power plants, which describes the main circulation circuit of the coolant. The technology is based on a joint one-dimensional and three-dimensional description of a reactor expanding the field of application of traditional one-dimensional system codes for describing fundamentally three-dimensional processes in reactor plenum. A description of the technology and verification data based on experimental studies is provided. The application of this technology to the analysis of the partial operating modes of the RITM-200 reactor plant was demonstrated, which made it possible to mitigate power limitations when disconnecting part of the heat exchange surface of the steam generator, reduce the costs of repair of the reactor plant associated with the replacement of steam generator cassettes, and avoid prolonged shutdown of a nuclear icebreaker.
About standards for hot water heating
Authors: Rotov P V , Sivukhin A A , Gafurov R A , Rotova M A
Published: March 2021

This article examines the existing legislative features of hot water supply, sanitary-epidemiological and hygienic requirements, as well as temperature standards for the quality of hot water. Practice shows that the standard for heating cold water, in contrast to the standard for heating, is universally underestimated. A feature of domestic hot water supply systems that significantly affects the efficiency of their operation is the high value of the circulation flow in the heat balance. At constant circulation and hot water temperature in the range from 60°C to 70°C, the value of the actual specific heat consumption for TPP can be more than 0.1 Gcal Gcal/m3. In sparsely populated homes, neighborhoods, and where some of the residents have switched to independent gas or electric water heating, this value is even higher. In order to determine the actual coefficients for heating cold water to provide utilities for hot water and comparison with the approved standard for heating, affect the distribution of losses in heat supply and hot water, conducted a study of the modes of operation of intrahouse systems of a number of apartment houses in the heating system of the city of Ulyanovsk. Based on the results of technical measures, the values of the actual coefficients for cold water heating were determined, ways to reduce excess heat consumption for cold water heating were proposed, and the technical feasibility of their implementation was determined.
Development of optimization criterions of regenerative heat exchangers
Authors: Shatskikh Yu V , Geller Yu A
Published: March 2021

The paper offers a simple method for analyzing the operation of regenerative heat exchangers, which significantly reduces the amount of calculations. Similarity criterions of regenerative heat exchange are obtained, which can be used to analyze the relationship of their thermophysical, structural and operating parameters. Similarity criterions were formulated by reducing the differential equation of regenerative heat transfer to a dimensionless form. These mathematical transformations were performed under the condition of regular regime of heating (cooling) of the checkerwork. As a result, three similarity criterions are obtained. The first criterion Kp1 determines the ratio between the heat-accepting capacity of the heat transfer agent and the heat-accumulating capacity of the checkerwork. The second criterion Kp2 is the ratio between the heat-receiving capacity of the heat transfer agent and the intensity of convective heat exchange. The third criterion Kp3 is the ratio between the heat-accumulating capacity of the checkerwork and the intensity of convective heat exchange. Similarity criterions include both the design and performance characteristics of the regenerative heat exchanger. Using these criterions, it is possible to choose a rational operating mode for existing heat exchangers. The proposed method of criteria analysis of regenerative heat exchangers was applied to hot-blast stove. In particular, the conditions for implementing a regular regime in heat exchangers are found. The regular mode is characterized by a linear temperature distribution over the height of the checkerwork, which can be obtained by selecting the appropriate ratio of the reduced costs and the time of the cooling and heating periods. It is also shown in what range it is advisable to change the design and operating parameters of the heat exchanger in order to obtain the maximum heating temperature of the blast-furnace air and the maximum heat availability factor. Since the similarity criteria are universal, the proposed method can be applied to other types of regenerative heat exchangers.
Numerical variational study of the M-shaped boiler invert furnace
Authors: Prokhorov V B , Kirichkov V S , Chernov S L , Kaverin A A , Fomenko N E
Published: March 2021

Nowadays the world and Russian energy sector seeks to reduce the use of coal for electricity production, however, in the future its significant part will remain in the fuel balance. Due to environmental and economic factors, coal generation has to use technologies to reduce polluting emissions and including also CO2 (HELE technologies) for maintain competitiveness. One of these technologies is the use of a coal for A-USC steam parameters steam turbine cycle. This paper describes the studies conducted to develop the optimal scheme for burning solid fuel in an A-USC M-shaped boiler invert furnace proposed by the Dept. of Thermal Power Plants of the National Research University “Moscow Power Engineering Institute”. Six schemes with a different arrangement of direct-flow burners and nozzles are considered. A test installation for isothermal physical modeling was made for scheme No.1. The results of physical modeling were compared with the results of the numerical simulation model of the test installation. Schemes No. 1-6 were investigated using numerical simulation in the ANSYS software package to identify the best conditions for the organization of staged fuel combustion at low emissions of nitrogen oxides. Scheme 6 is recognized as the most optimal and will be used to create an isothermal physical test installation and conduct numerical simulations of the combustion process for a full-scale furnace model.
Development of a consensus algorithm and data block structure based on digital blockchain technology for distributed systems for storing information about the state of power equipment
Authors: Sultanov M M , Smirnov AA , Yurov VA , Lunenko VS
Published: March 2021

The article considers the main directions of technological transformations in the Russian electric power industry, which performs an integrating function for the fuel and energy complex of the country. The methods of achieving and ensuring a high level of reliability and safety of power equipment for thermal power plants, hydroelectric power plants, and nuclear power plants at all stages of their life cycle from design to decommissioning are considered. The issues of creating a unified system of information support for power equipment of generating systems for thermal power plants, hydroelectric power plants, nuclear power plants and power complexes based on renewable energy sources, taking into account the technical condition during the entire life cycle, are studied. In order to improve the security and efficiency of planning and forecasting of power equipment operation modes, it is proposed to consider an information model consisting of a centralized data warehouse and a distributed registry based on blockchain technologies. The principle of operation of a distributed closed registry, the structure of data blocks, and the algorithm of consensus between private users of the registry are considered.
Procedure for assessment of technical condition of equipment of generating systems taking into account control effects on the basis of data management complex of monitoring and diagnostics system
Authors: Sultanov M M , Tyagunov M G , Baydakova N V
Published: March 2021

This work presents the results of the analysis of existing methods for assessing the technical condition of generating systems’ equipment, the advantages of maintenance and repair systems by the actual condition are considered.
Modelling of developing capacity of power systems based on hybrid power complexes by reliability indicators
Authors: Shestopalova T A , Sultanov M M , Zhelyaskova O I
Published: March 2021

Currently, short-term power supply failures of consumers are the main cause of failures in the stability of normal operating modes of the system. The result of real power supply failures is emergency modes due to improper load distribution. We propose the joint operation of algorithm and the program for forecasting capacity of power transmission lines in order to ensure reliable uninterrupted operation of power system. The results of the study are presented on the example of hybrid operation of the Thermal Power Plant (TPP) and Mini hydroelectric power plant (HPP).
Application of the underground natural brines for energy coal enrichment
Authors: Burakov IA , Burakov AY , Nikitina IS , Hn Aung , Va Ye , Anufrieva EA , Bragina NA
Published: March 2021

As part of the development of coal generation in the Russian Federation, one of the important issues is the use of enrichment processes for thermal coal. There are a large number of mineral processing methods, namely: gravity processing, flotation processing, methods of magnetic and electrical processing, as well as special processing methods, from which there are: radiometric, chemical and mechanical methods of coal preparation. Based on the results of an economic evaluation of existing enrichment methods, the team of authors identifies the gravity enrichment method as the most applicable method for thermal coals in view of the low cost of the resulting coal concentrate during its implementation. Among the existing methods of gravitational enrichment, one can distinguish enrichment in a heavy medium, as the most easily implemented, and again, the cheapest of all existing methods of gravitational enrichment. In industry, magnetite and water-sand suspensions are most often used as a heavy medium. The advantage of using these difficult media is the depth of the enrichment process - the output of coal concentrate and the amount of valuable rock recovered (combustible part of the fuel). The downside is the difficulty in operation - the suspensions must be homogenized, and the contamination of the resulting coal concentrate with weighting particles (magnetite or sand), which reduces the amount of valuable rock. It is proposed to solve this problem by using sodium chloride and calcium chloride as a natural medium in underground brines. According to the results of the work, the main indicators of the enrichment processes are estimated when using brines as a dividing medium.
Evaluation of the possibility of using underground salts for the regeneration of Na-cationite filters of WTP TPP and NPP in the territory of the CFD
Authors: Burakov A Y , Burakov I A , Nikitina I S , Verkhovsky A E
Published: March 2021

When studying groundwater in the Central Federal District (CFD), it was found that the mineralization of groundwater, including brines, increases “from top to bottom” - as the depth of the aquifer complex. The possibility of using underground natural chloride sodium brines for the regeneration of Na-cationite exchange filters is determined by two boundaries - upper and lower. The upper limit of applicability of the brines is controlled by the salinity of the brines of 165 g/dm3, that is, you can use brines with a salinity of at least 165 g/dm3. The lower limit of applicability of the brines is determined by the ratio of the content of sodium ion (in mEq/dm3) to the total hardness of the brine (in mEq/dm3), which should be at least 3.5. In addition to these requirements, the ability to use underground natural chloride sodium brines as a regeneration solution for Na-cation exchange filters is influenced by the total hardness of the brine depending on the total salinity of the brine: to prevent an increase in the counterionic effect, the total hardness of the brine should not exceed 500 mEq/dm3 with a total mineralization of 100 - 150 g/dm3, and should not exceed a value of 1,500 mEq/dm3 with a total mineralization of 250 - 300 g/dm3. The regionalization of the territory of the CFD, taking into account these requirements, revealed 41 thermal power plants and one nuclear power station as potential consumers of underground sodium chloride brines. In addition, on the basis of regionalization, aquifer complexes containing underground brines of conditional quality, depths of aquifer complexes, and approximate depths of design salt-producing wells, on which the cost of well construction largely depend, were determined.
Systemic issues of the power plants APCS development technology and performance paradigm
Authors: Tverskoy Yu S , Golubev A V , Muravev I K , Nikonorov A N , Kolesov I A , Gajdina Yu A
Published: March 2021

Current development of power engineering in Russia is characterized by deployment of power units with distributed multifunctional automatic process control systems (APCS) based on software and hardware systems (I&C) complex with hierarchical network structure. I&C is the backbone of this structure and APCS creates common information and technological environment of the power unit. Key issues of the multifunctional APCS are associated with lack of the technical efficiency of the I&C, usage of unproven control algorithms and immaturity of the system development technology. Overcoming the identified key issues in the development of the technology of creating I&C and APCS as a whole is associated with the formation of special functionality developed by I&C, their capabilities to use mathematical models of control objects and processes in real time (RT), assessing the information properties of controlled and uncontrolled parameters and generated signals. Performance paradigm (price/quality) of the APCS which answers on these questions can be received only after putting system in the operation and caring additional work on the assessment and optimization of information-functional and technical structures of APCS. The report discusses some new results in solving the indicated issues as part of improving the technology of modern APCS and prospects for their development as the main scientific direction of the Department of Automatic control Systems of ISPU.
Problems of assessing the energy systems reliability in Russia
Authors: Kondrateva O E , Loktionov O A , Vanin A S , Borovkova A M
Published: March 2021

The paper analyzes the main approaches to assessing the energy systems reliability currently used in Russia. The main terms and requirements for the reliability of energy systems are defined, and gaps in the regulatory framework in this area are indicated. Based on the review and analysis of regulations and scientific research on ensuring the uninterrupted operation of power systems, a universal classification of reliability types is proposed. The expediency of developing a comprehensive approach to assessing system reliability based on the analysis of adequacy and operating reliability is shown, and the directions for improving existing methods for evaluating various types of power systems reliability are determined.
Estimation of reliability of TPS as a complex system using logical probabilistic methods
Authors: Kondrateva O E , Borovkova A M , Bayeva P N , Cherkasskiy E B
Published: March 2021

The existing regulatory requirements for reliability assessment and the economic necessity of this assessment are considered. Modern methods and approaches to assessing quantitative indicators of reliability of structurally complex systems, such as thermal power plants, are presented. The expediency of using software systems for calculating reliability based on the General logical-probabilistic method is proved. On the example of one power unit, the application of a domestic software package for modeling and calculating reliability and safety using logical-probabilistic research methods is clearly presented. The existing problems of forecasting reliability indicators after the technical impact are described.
Verification of digital models of coolant self-oscillation of NPP with VVER
Authors: Proskuryakov K N , Anikeev A V , Afshar E
Published: March 2021

The results of verification of VVER-440 digital acoustic model are presented. The vibration control system of the main equipment, named SÜS, which is used in normal operation of nuclear power plants (NPP), is used to measure coolant pressure pulsations and mechanical vibrations. The method of calculation of acoustic standing waves (ASW) generated in the equipment is developed; the calculated values of ASW frequencies are in agreement with the results of measurements of signals from pressure pulsation sensors. It is proved that in the nominal and start-up modes, as a result of transformation of stochastic random pulsations caused by turbulence and vortex formation into ordered oscillations, acoustic waves appear. It is shown that the frequencies of acoustic waves depend on the operating conditions and can coincide with the vibration frequencies of the equipment. It is proved that the acoustic properties of a nuclear reactor, regardless of the number of coolant circulation loops, are similar to the properties of a group of simultaneously used Helmholtz resonators. The use of the acoustic model of the reactor allows optimizing design and engineering solutions by creating equipment capable of minimizing unwanted cyclic loads. This capability is the most important to ensure long - term operation in manoeuvrable modes of small modular reactors.
EU countries experience analysis in using various fume gas treatment systems from acid gases removing for WTE Plants
Authors: Dudolin A A , Efremov A N
Published: March 2021

The existing method of selecting the structure of a Waste to energy plant (WTE plant) for thermal utilization of MSW in the Russian Federation is often not applicable to real objects, which leads to the need for each project to search for new methods, select the criteria for choosing the best technology.

Conducting a comparative analysis of various structural schemes WTE plant, common in the EU and Japan, will help to identify their main advantages and disadvantages, determine the scope of application.

This article describes the statistical indicators of the flue gas treatment system (FGT) from acid gases, which can be applied at the stage of feasibility study, development of basic engineering. When building a WTE plant in urban conditions and striving to minimize the gross emissions of acid gases into the atmosphere, a wet FGT cleaning system can be recommended, which will provide low emissions of HF, HCl, and SOx. The system with a wet reactor will reduce the gross emissions of harmful substances during the construction of WTE plant with high-capacity, and in this case it is justified.

When building WTE plant with medium-capacity (up to 350 thousand tons of MSW per year), it may be recommended to use a semi-dry and dry FGT, while the highest preference should be given to the technology with a semi-dry reactor as the most promising.
A mathematical model of the carbon dioxide production unit for a cogeneration power station
Authors: Korshikova A A , Pechenkin S P , Borisova P N
Published: March 2021

A mathematical model is presented of a unit for carbon dioxide production using an absorption-desorption method on the basis of a generation facility with a cogeneration steam turbine unit (STU).
Hygroscopic method application and realization for demineralization of sea and salted water
Authors: Sokolov P S , Kozlova M V , Bannikov A V
Published: March 2021

The desalination of sea and salty water is one of the alternatives in solving the problem of freshwater recourses shortage. Reverse osmosis and distillation desalination methods are widely used for industrial, household and potable water supply. Each method requires definite energy and material costs. That’s why the problem of developing and researching the most effective energy and financial desalination plants is up to date. The aim of our research is the analysis of self-sufficient hygroscopic desalination plant operation efficiency. The comparative analysis of the most popular desalination methods has been carried out. The authors describe the desalination plant components and its operation principle. The main factors that influence plant intensity are determined. The plant developed efficiency is to increase the performance due to additional steam generation on the basis of steam-gas-liquid balanced condition law. Energy effectiveness increase is reached thanks to heat energy recycling in a condenser-separator and in a fresh water coil. The authors state that one of the best ways to accelerate the hygroscopic desalination process is to increase the initial temperature of water in barbotage area. The plant developed is characterized with high energy effectiveness, low costs and high quality of fresh water obtained.
Determination Of Thermal Technical Characteristics Of Sewage Sludge
Authors: Bernadiner I M , Khoreva P V , Ekimova V A
Published: March 2021

One of the largest environmental problems of the Russian Federation is the pollution of the territory waste. The focus is on waste generated during the treatment of urban wastewater - sewage sludge and sewage sludge (SS). The shortage of areas sharply raised the issue of eliminating these wastes. The main elimination method is high temperature combustion. The complex process of elimination requires preliminary heat engineering studies of sewage sludge. In the scientific work, gas-analytical studies of flue gases were carried out, the experimental process of preliminary drying of sewage sludge was reproduced, and calorimetric tests of specific samples of precipitation were calculated with recalculation to the lower calorific value.
Electrocatalytic materials for solid polymer electrolyte water electrolyzers
Authors: Pushkarev A S , Pushkareva I V , Akelkina S V , Kozlova M V , Grigoriev S A , Kuleshov N V , Bessarabov D G
Published: March 2021

In the present work the activity and stability of the IrOx/TiOx catalyst obtained by the polyol approach in the oxygen evolution reaction (OER) were studied in comparison with the commercial analogue IrOx. Electrochemical studies were provided, including accelerated stress testing. The synthesized IrOx/TiOx catalyst demonstrated higher OER activity and stability than the commercial IrOx, and the obtained results allow to suggest and discuss possible mechanisms of the studied catalysts degradation. Tests of membrane-electrode assemblies based on synthesized IrOx/TiOx catalysts in SPE water electrolyzer demonstrate the possibility to significantly reduce the noble metal content on the anode..
Parametric optimization of the semi-closed oxy-fuel combustion combined cycle
Authors: Kindra V O , Kaplanovich I B , Smirnov M V , Naumov V Y , Zonov A S
Published: March 2021

The report discloses thermodynamic studies of the semi-closed oxy-fuel combustion combined cycle. The computer simulation and parametric optimization approaches are described in details. The oxy-fuel cycle net efficiency in relationship to the carbon dioxide turbine exhaust pressure and the steam turbine inlet pressure is shown. The power production efficiency reduction is related to the turbine cooling losses is described. It is shown that the semi-closed oxy-fuel combustion cycle maximal net efficiency of 52.5% occurs at the initial temperature and pressure 1400°C and 60 bar at the carbon dioxide turbine exhaust pressure 0.5 bar and the steam turbine inlet pressure 90 bar. The cooling losses consideration leads to the net efficiency of 47.76% that is reached at the carbon dioxide turbine exhaust pressure 1 bar and the steam turbine inlet pressure 90 bar.
Assessment of scale formation in heat exchangers
Authors: Matukhnov T A , Matukhnova O D , Yurkina M Y , Khomchenko N V
Published: March 2021

The paper evaluates the influence of the scale formation on the inner surface of the heat exchanger on its technical characteristics. The subject of research is a heater 12 OST 34-588-68 Number 12 diameter of 219 of the second stage of hot water supply, intended for heating cold water into a hot water supply system. A survey of the Central heating point and connected heat and water supply systems located in the city of Moscow was conducted. For the study, an analysis of indicators of water quality at a heat point was carried out. In the course of the work, the following were calculated: the intensity of scale formation, their thickness, and also the deviation of the calculated value of the formed deposits from the actual one obtained by field measurements was found. As a result of the work, an increase in the hydraulic resistance inside the tubes of the heat exchanger was calculated in connection with the formation of deposits and an increase in the consumed electricity to ensure the required parameters of the hot water supply system.
Monitoring and updating of specific electric loads of residential and public buildings
Authors: Soluyanov Y I , Fedotov A I , Akhmetshin A R , Khalturin V A
Published: March 2021

Design organizations use standard specific load values to calculate the power consumed by residential and public buildings. The practice of operating power supply systems has shown that in most cases the actual load is 1.5 – 2.5 times less than the calculated load. The constructed cable networks and transformer substations of 0.4 / 10 kV are actually underloaded. The Association “Roselektromontazh” conducted research of TS loading of 0.4/10 kV in several cities of the Russian Federation, the results of which determined that about 80% of TS work with a maximum load of less than 30% during the year. The capacity of power transformers is selected according to account 70% of the total maximum load in the rated mode. Low load of power transformers leads to an increase in losses in them by comparing those working with a load of 70%; an inefficient use of investments. To solve this situation, it is proposed to monitor electric loads with subsequent updating of standard documents in terms of calculated specific electric loads, which will bring the calculated values closer to the actual ones to increase economic efficiency in the construction and operation of the power grid complex.
Hybrid energy systems based on renewable energy sources in various climate zones
Authors: Gasho E G , Kiseleva A I , Romanov G A
Published: March 2021

Alternative and renewable energy sources are slowly but surely strengthening their positions in the fuel and energy balance of countries. The presented article assesses the potential use of non-traditional and renewable sources for heat supply systems. World experience in introducing alternative energy sources allows us to highly evaluate the implementation of such systems. Application of energy supply schemes based on renewable energy sources is difficult for several reasons in Russia. The study addresses the key problems of the active use of hybrid systems and suggests ways to solve them.
Modelling of autonomous power source for gas distribution station using ASPEN HYSYS
Authors: Dronov S A , Fedyukhin A V , Panarin V E , Chernykh A S , Yavorovsky Y V , Khromchenkov V G , Martynov A V
Published: March 2021

The article is devoted to the study of energy conservation issues in gas transmission and gas distribution systems. In the Aspen HYSYS software package, the authors developed a model of an autonomous power source for gas distribution station (GDS). A brief simulation sequence is described. The dependence of the electric power of the expander-generator unit on the natural gas flow ratio is determined.
High-pressure alkaline water electrolyser of coaxial configuration
Authors: Kuleshov V N , Kurochkin S V , Kuleshov N V , Udris E Ya
Published: March 2021

At present, hydrogen is increasingly being used in various industries. Moreover, among all technologies for producing hydrogen, the proportion of electrolytic hydrogen is constantly increasing. The most widely used technology is industrial water alkaline electrolysers of various capacities. In parallel, the direction associated with the development of high-pressure water alkaline electrolysers begins to develop. This paper considers the issue of creating and testing a high-pressure water alkaline electrolyser of coaxial configuration. Possible problems are considered during the operation of its components under high pressures, and ways to solve these problems. The proposed type of coaxial configuration and the changes made to the composition of the diaphragm material made it possible to reach a pressure of 100 bar.
Assessment of economic efficiency of unconvential renewable energy sources utilization for energy supply of individual residential houses
Authors: Pavlenok A A , Kalenskaya E V , Frey D A
Published: March 2021

Practical topics of evaluation of efficiency of heat pumps usage for individual residential houses heating with comparing of different technical options and solutions. Power of the heating system on the basis of geothermal heat pump on the example of specific building investigated. The role of heat insulation in heat losses and influence on the required power of heating system assessed, economical aspects evaluated. Comparison with alternative heating on the basis of main (pipelined) gas made in order to get objective picture of competitiveness of renewable energy sources with traditional ones in the existing regulatory and energy market conditions.
An analysis of the convective drying kinetics of wild grass seeds
Authors: Berezina T S , Vlasenko G P , Alekseev R O , Sabanova A N , Sabanova E N , Toepel T , Schuetz W
Published: March 2021

The experimental results of the sorption properties and the capillary-vesicular structure of wild-growing seed grass are given in this study. This data can be applied to refining the drying process parameters. Methods for improvement of drying plants used for heat treatment of wild-growing seed grass, as well as for technical plant varieties are proposed.
Developing Community Information Group Website to Improve Digital Literacy
Authors: Setyaningsih Rila , Utama Shoffin Nahwa
Published: March 2021

Community Information Group is a public service institution as a community information center at Biting Ponorogo. Dissemination of information to the public is often an obstacle due to limited communication media. Then, word of mouth is often inaccurate, causing miscommunication. This research aims to develop a website as a community information center. As well as being a communication and information medium, this website development also aims to improve community digital literacy. This research used the System Development Life Cycle method. This study succeeded in developing a website for the Biting Community Information Group. The feedback from Biting Community Information Group peoples expected that these websites could be developed as a medium of communication and information for the community. This website can be accessed via a search engine (https://kimbiting.com/). The next research can measure the effectiveness of the Biting Community Information Group website as the communication media. Besides, future research also can develop another communication medium based on information and communication technology.
A preliminary study of biomass briquettes based on biochar from pyrolysis of durian shell
Authors: Saputro H , Yosin K A , Wijayanto D S , Muslim R , Fitriana L , Munir F A
Published: March 2021

Utilization of durian shell waste as feed biomass in the pyrolysis process has been carried out. The results of the pyrolysis process produce bio-oil, gas, and biochar. Pyrolysis biochar can be used as a potential source of energy by converting it into biochar briquettes. This research is making biochar briquettes using a mixture of water and starch. The ratio between biochar and starch is 9: 1. The mixed material is then made biochar briquettes using a briquette printer with a pressure of 0.5 MPa. The results showed that biochar briquettes had better performance than durian shell biomass.
Performance Test of Winglet Horizontal Shaft Wind Turbine Against Cut In Speed
Authors: Sangidzun Achmad , Wijayanto Danar Susilo , Saputro Herman , Soenarto  , Triyono Mochammad Bruri
Published: March 2021

Wind turbines are devices that convert wind kinetic power into electrical energy through generators. Currently there has been a lot of research on horizontal shaft type wind turbines to improve systems that work optimally. This study uses a 3 blade horizontal winglet wing turbine wind turbine with variations in pitch angle to increase the cut in speed value. The pitch angles used are 0°, 2°, 4°, 6°, 8°, and 10°. This study uses an NACA 4412 aerofoil with winglets added to the blade tip. The research method used in this study is the experimental method. The results showed that the highest cut-in speed values of three, four and five blades were obtained at a pitch angle of 10° at wind speeds of 2.3 m/s, 1.8 m/s and 1.8 m/s.
Analysis of Learning Speaking Skills Using the WhatsApp Application in Elementary Schools
Authors: Fahrudin Sigit Hasan , Winarni Retno , Winarno
Published: March 2021

The Covid-19 pandemic approaching the 21st century has had a significant impact in all fields, including education. Finally, all learning activities are carried out online or online. This study aims to analyze the implementation process of learning speaking skills using the WhatsApp group application, the obstacles faced, and the teacher’s efforts to improve speaking skills. This research was conducted at SD Negeri Katikan 1 and SD Negeri Katikan 2, Kedunggalar District, Ngawi Regency, East Java. This research uses descriptive qualitative research methods. The subjects used in this study were teachers of class V SD Negeri Katikan 1 and SD Negeri Katikan 2. The sampling technique used was purposive sampling. Data collection techniques used in this study were in-depth interviews and document analysis. Data analysis used interactive analysis techniques by Miles and Huberman. The result of this research is that the Covid-19 pandemic has had a huge impact on the learning process, learning elementary school speaking skills which are usually carried out offline has now been converted into online or online learning via WhatsApp. Learning of speaking skills is carried out through the WhatsApp feature, video calls, learning videos, pictures, and voice notes. Barriers to online learning are network problems, ownership of an android cellphone, and student discipline. The efforts made by the teacher to improve students’ speaking skills in online learning through WhatsApp is to familiarize students with speaking in every learning activity, such as apperception activities, core activities (presentation of material and assignments), and other activities (leading prayer, presentation).
The Implementation of Online-Based New Student Admissions in Surakarta
Authors: Istiqomah Rizlaili , Kristiani  , Wahyono Budi
Published: March 2021

The purpose of implementing this research is to determine the implementation of online-based new student admissions in the city of Surakarta, and the effectiveness of the implementation of online-based new student admissions in Surakarta. In the implementation this research using descriptive research with a qualitative approach. Technique for search subject with purposive sampling and snowball sampling, for collection data observation, interview and documentation, and to testing the validity of the data used data triangulation and methodological triangulation The results showed that the implementation of online-based new student admissions in Surakarta was implemented using a zoning system. Implementation of online-based new student admissions, there are several stages of implementation, namely starting with the preparations made by Education Department of Surakarta, then the implementation of online-based new student admissions carried out by Junior High Schools supervised by the Education Department of Surakarta. Online-based admission of new students begins with registration, filing of requirements, inputting data into the system, selecting, announcing the results of selection and re-registration activities; and in implementing online-based new student admissions at the Education Department of Surakarta, it already has an effective system in terms of indicators of goal achievement, availability of resources, good internal processes, and constituency satisfaction in implementing online-based new student admissions.