Vestnik MÈI最新文献

{"title":"Torrefaction of Food Waste in Vietnam for Using It as an Alternative Energy Source","authors":"Tatyana Stepanova, Dinh Khuong Nguyen","doi":"10.24160/1993-6982-2023-4-102-108","DOIUrl":"https://doi.org/10.24160/1993-6982-2023-4-102-108","url":null,"abstract":"In developing countries like Vietnam, there are not many methods for food waste reprocessing. Although food waste accounts for 40% of municipal solid waste, the energy potential of the former is very low in view of a high moisture content, and most of food waste is disposed in landfills. Food waste is the main cause of water and air pollution problems around landfills, and they have a very negative effect of the environmental conditions of cities. To reduce the burden on the environment, various food waste processing methods are developed and investigated, which is a matter of concern in many developing countries. However, in view of such characteristics of food waste as high moisture content (up to 70%) and low heating value (less than 4.6 MJ/kg), the use of a number of methods for processing it is difficult. To overcome these difficulties, the torrefaction method can be used as a pretreatment measure to improve the food waste characteristics. A data collection method and an experimental method involving the use of a high-temperature furnace to study the influence of temperature in the range from 225 to 300 °C on the torrefaction process have been implemented. The study results have shown that the torrefaction product’s higher heating value increases with increasing the temperature from 225 to 300 °C, while the energy yield decreases by almost 16%. The product’s highest heating value obtained at 300 °C is 26.41 MJ/kg, which is equivalent to the heating value of coal. This shows that torrefied food waste can potentially be used as an alternative fuel source in the future. The obtained results will be applied in the research and development of methods for torrefying not only food waste, but also other types of organic waste with a high moisture content and in the development of thermal process schemes for producing fuels from energy-carrying waste.","PeriodicalId":499319,"journal":{"name":"Vestnik MÈI","volume":"123 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135202720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Parametric Identification of an Inertial Object from a Fragment of a Transient with Non-Zero Initial Values","authors":"Irina Kazyukova, Oleg Kolosov","doi":"10.24160/1993-6982-2023-4-137-145","DOIUrl":"https://doi.org/10.24160/1993-6982-2023-4-137-145","url":null,"abstract":"The article analyzes two approaches to solving the problem of parametric identification of a linear inertial object from a fragment of a transient with nonzero initial values. This formulation of the problem is relevant in practice not only for the stepwise form of the input signal, but also when a rectangular testing pulse is applied to the dynamic object input. With such statement, the parameters of input test signals are considered to be known. In the latter case, the maximal duration of the processed fragment of the recorded transient fragment is limited by the duration of the testing pulse. The problem is reduced to estimating the parameters of the dominant time constant in the description of the object’s transfer function and the object’s total transfer coefficient from the intermediate fragment of the transient taking into account nonzero initial conditions. A comparative analysis of two considered approaches to solving the problem is carried out. The first approach uses inverse digital transformation (differentiation) algorithms, and the second approach uses an estimate of the parameters of the function approximating the recorded fragment as the identified object’s model. In all cases, the least squares method is used to approximate a fragment of the transient. The test examples show better accuracy of the second approach in the presence of a random noise component in the processed signal. Using the example of processing fragments of electroretinograms in ophthalmology, the possibility of expanding the space of informative signs for the diagnosis of retinal diseases is shown. For these purposes, it is possible to use the results of parametric identification a fragment of a general electroretinogram, which is an intermediate part of the retinal reaction in response to a light pulse.","PeriodicalId":499319,"journal":{"name":"Vestnik MÈI","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135207248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical Simulation of the Loss of Offsite Power to the VVER-1200 Nuclear Power Unit Auxiliaries","authors":"Mikhail Polevoi","doi":"10.24160/1993-6982-2023-4-130-136","DOIUrl":"https://doi.org/10.24160/1993-6982-2023-4-130-136","url":null,"abstract":"Justification of the cyclic strength of equipment and pipelines is an integral part of the VVER-based reactor plant basic design. The results of thermal-hydraulic calculations of variations in the primary and secondary coolant circuit parameters in various emergency modes serve as input data for this justification. Loss of offsite power to plant auxiliaries is one of the considered plant operation conditions. In view of loss of power supply to the plant auxiliaries, all electrically driven feed pumps are disconnected under these conditions, thus resulting in the loss of feedwater flowrate. As a consequence, the water level in all steam generators starts to decrease until the setpoint for switching on the electrically driven emergency feedwater pumps is reached. In the course of supplying emergency feedwater to the steam generators, steam condensation occurs. This entails a drop of pressure in the steam generators, which, in turn, can cause disconnection of the emergency feedwater pumps on reaching the relevant tripping setpoint. The results of a numerical simulation of the “Loss off site power for plant auxiliaries” mode for a VVER-1200 nuclear power unit carried out using the KORSARGP thermal-hydraulic code are presented.","PeriodicalId":499319,"journal":{"name":"Vestnik MÈI","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135202570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Pilot Industrial Water Treatment Plant for the Primorskaya State District Power Plant Heating System","authors":"Sergey Gromov, Konstantin Orlov, Elisey Selivanov","doi":"10.24160/1993-6982-2023-4-62-71","DOIUrl":"https://doi.org/10.24160/1993-6982-2023-4-62-71","url":null,"abstract":"Matters concerned with the development of a water treatment plant (WTP) for making up the heating system for the conditions of the Primorskaya State District Power Plant (operated by JSC Far East Generating Company) using a nanofiltration technology are considered. The WTP specific feature is that it uses nanofiltration to prepare water for making up an open-type heating network, which is the world’s first experience at an industrial level for such system. The use of nanofiltration makes it possible to obtain treated water of significantly better quality in terms of sanitary standards and rules in comparison with existing installations and ensure epidemiological safety of treated water. In addition, in comparison with the reverse osmosis technology, the use of nanofiltration features higher hydraulic efficiency and higher pH, due to which there is a reduced NaOH dose in treated water.","PeriodicalId":499319,"journal":{"name":"Vestnik MÈI","volume":"124 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135207262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On Key and Multiple Space Key Pre-Distribution Schemes in Wireless Sensor Networks with a Combinatorial Block Design Structure","authors":"Aleksandr Frolov, Natalya Kochetova","doi":"10.24160/1993-6982-2023-4-162-176","DOIUrl":"https://doi.org/10.24160/1993-6982-2023-4-162-176","url":null,"abstract":"The aim of this work is to present, along with performing their comparative analysis, the structural characteristics and security parameters of the Key Pre-Distribution Schemes (KPDS) and Multiple Space Key Pre-Distribution Schemes (MSKPDS) in wireless sensor networks (WSN) with combinatorial block design (CBD) and combined combinatorial block design (CCBD) structure. A KPDS is determined by a totality of the sets of WSN nodes, in the key memory of which the same keys are pre-recorded for confidential exchange between the nodes of these sets. An MSKPDS differs in that instead of keys, identical pre-keys are written to the specified nodes, which make it possible to calculate, using node identifiers, different keys for confidential communication between the nodes of these sets. As a rule, the specified sets of nodes correspond to blocks or dual blocks of a certain CBD or blocks and dual blocks of a certain CCBD. If direct links between the nodes of these sets are provided in the WSN, and there are no direct links between other nodes, then, by definition, the KPDS, MSKPDS and WSN are built with the structure of this CBD or CCBD. The CBD structure is determined by a graph on the set of its blocks or dual blocks. Vertices that have common elements are regarded as adjacent ones. The nodes and links of the WSN with the CBD structure correspond to the vertices and edges of this graph. In such WSN, the sets of the KPDS or MSKPDS nodes, to which common keys or common pre-keys are assigned, are composed of nodes corresponding to the vertices of the CBD graph containing the element corresponding to this common key or pre-key. The CCBD structure is determined by a graph on a set of pairs (a CBD block, an element of this block). Vertices that have the same first or the same second elements are adjacent ones. The WSN with the CCBD structure is determined by this graph according to the same rule. The KPDS and MSKPDS in it are defined on the sets of all vertices of this graph that have the same first or the same second components (constituting the CCBD blocks and dual blocks). As a result, two keys are assigned to each node. Once key identifiers are assigned to the vertices, the above-mentioned CBD and CCBD graphs become key sharing graphs (KSG). The objective of this work is to perform a comparative analysis of the structural characteristics (the longest length of the shortest path in the KSG, the size of the node key memory), deterministic and probabilistic security characteristics of the MSKPDS with the CBD structure and the MSPDS with the CCBD structure. Two CBDs were chosen for considering specific cases: symmetric (a projective plane) and asymmetric (a unital combinatorial block design). It is shown that the advantages of MSKPDS with the CCBD structure are a smaller share of compromised direct links when one node is compromised and a small amount of key memory (equal to 2 or linearly dependent on the security parameter), and the shortcoming is that there ar","PeriodicalId":499319,"journal":{"name":"Vestnik MÈI","volume":"173 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135203622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design and Simulation of a 3 MW Photovoltaic Power Plant Using the MATLAB and Simulink Tools","authors":"Akhmed Saeed Al-akayshee, Ibragim Alwazah, Oleg Kuznetsov","doi":"10.24160/1993-6982-2023-4-28-40","DOIUrl":"https://doi.org/10.24160/1993-6982-2023-4-28-40","url":null,"abstract":"The growing demand for energy in developing countries raises the energy security issue and leads to the need of using the potential of renewable resources. An analysis of the parameters characterizing the power output produced by grid-connected solar photovoltaic (PV) systems can help in designing, operating, and maintaining new systems for generating electricity from the solar radiation energy. Simulation and analysis of PV energy conversion systems are necessary for solar power plant designers to perform studies that will make it possible to accurately predict the expected power output under varying weather conditions. The model helps predict the behavior and characteristics of a PV module based on the equivalent circuit implemented in a mathematical model using the Matlab/Simulink environment for various environment temperature and solar radiation values. The article addresses matters concerned with selecting the components of a PV electricity generation system and simulating it using the MATLAB/Simulink software. The power plant consists of PV panels connected in series and parallel, a DC-DC boost converter, and a three-phase inverter, which is connected, via a step-up transformer, to a 33 kV medium voltage network. The DC-DC boost converter control system uses a maximum power point tracking (MPPT) controller, and the inverter is controlled using a PI current controller.","PeriodicalId":499319,"journal":{"name":"Vestnik MÈI","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135203626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Verification and Development of a Computation Methodology for Modeling the Axial Compressor Wheel Space Erosion Wear","authors":"Sergey Bogdanets, Vitaliy Blinov, Oleg Komarov","doi":"10.24160/1993-6982-2023-4-109-121","DOIUrl":"https://doi.org/10.24160/1993-6982-2023-4-109-121","url":null,"abstract":"The scientific and technical problem of modeling gas-abrasive wear of an axial compressor blade row is investigated. The objectives of the study are to determine the current state of this area of research and develop a gas-abrasive wear calculation methodology. Attention is focused on the verification of the computation method based on the published results of experiments with gas-abrasive erosion in the round pipe swivel channel. A detailed review of the domestic and foreign literature is carried out. The study is aimed at predicting the extent of blade row gas-abrasive wear using the computational fluid dynamics methods. A step-by-step description of the algorithm for solving the problem by a numerical method with a historical review of erosion models developed by other researchers is given. An algorithm for calculating gas-abrasive wear in an axial compressor is elaborated, and possible algorithms for calculating the fluid dynamic characteristics of a compressor subjected to gas-abrasive wear are analyzed. The study results can be used in designing the axial compressors of gas turbine units that operate under polluted air conditions. Thus, by using the numerical method, it is possible to carry out a qualitative and quantitative analysis of an axial compressor’s wheel space gas-abrasive wear. The main contribution in the erosion wear computation accuracy is introduced by a correct calibration of the erosion model. Therefore, to obtain adequate results, reliable experimental data on determining the properties of interaction between the eroding particles and the wall are required.","PeriodicalId":499319,"journal":{"name":"Vestnik MÈI","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135207255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Advanced Technology for the Manufacture of Electrical Insulating Materials","authors":"Dmitriy Luchko, Andrey Papkov, Igor Kuimov","doi":"10.24160/1993-6982-2023-4-11-15","DOIUrl":"https://doi.org/10.24160/1993-6982-2023-4-11-15","url":null,"abstract":"Breakdowns, interturn short-circuit faults, or low resistance of the ground wall insulation of the armature coils or main/auxiliary poles account for a significant (about 40%) part of traction electric motor (TED) failures. Therefore, one of the main objectives pursued by electrical insulation manufacturers is to improve the insulation quality and increase its service life. The insulation quality is improved both by replacing insulation components and by perfecting the manufacturing technology. The article describes an alternative technological process for manufacturing the insulating tapes used as ground wall insulation of coils based on a powder technology. The schematic process circuits of equipment for producing electrical insulating tapes according to both the technologies are given; the shortcomings of the currently existing technological process are pointed out, and methods for estimating the coil insulation quality of large electrical machines are described. The costs for manufacturing a production unit are compared in physical and monetary terms. The fiberglass and mica based Elmikapor® tape produced by ZEIM Elinar LLC was used as an object of research. Industrial tests of the insulation were carried out, and a conclusion has been drawn from the obtained test results that the use of powder technology shortens the impregnation time by a factor of 1.5 and reduces the cost of manufacturing insulation for electric machines by impregnation under vacuum, improves the impregnation quality, and, consequently, the durability of the insulation system and the electric machine operation time between overhauls. The described technology also features an essentially smaller negative impact on the environment.","PeriodicalId":499319,"journal":{"name":"Vestnik MÈI","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135207253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Studying the Pipeline Crack Growth in the Analysis of Nuclear Power Plant Internal Flooding and Estimating the Maximum Possible Leak Rate","authors":"Oleg Goryunov, Aleksandr Sovgirya, Nadezhda Sovgirya","doi":"10.24160/1993-6982-2023-4-122-129","DOIUrl":"https://doi.org/10.24160/1993-6982-2023-4-122-129","url":null,"abstract":"Regulations concerned with the deterministic analysis of the impact of flooding on the NPP safety stipulate the need to evaluate the degradation degree of defense-in-depth (DiD) levels. The results of this analysis serve as input data for the probabilistic safety assessment (PSA) and selection of technical solutions. To estimate the flooding zone and the list of dependent failures, it is necessary to postulate the size of a pipeline or tank leak. The leak flowrate has an essential effect on the analysis result: the flooded zone size, the list of failed equipment components, and the characteristics of protective measures. The currently effective Federal Codes and Regulations of the Russian Federation do not stipulate procedures for estimating the consequences of flooding in the framework of a deterministic approach, and the use of foreign calculation procedures (ANSI / ANS-58-2, NUREG / CR-3464) yields ambiguous results. The conservatism level of foreign approaches is evaluated taking into account the laws of fracture mechanics. To this end, the maximum allowable sizes of defects in pipelines of various standard sizes that do not lead to a guillotine rupture and limit the maximum flowrate values are estimated. The results of the comparative analysis and calculations will be applied as part of the safety justification of Russian and foreign NPP projects.","PeriodicalId":499319,"journal":{"name":"Vestnik MÈI","volume":"191 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135207397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Generating Reference Actuation Signals of Relay Protection Devices for Automated Functional Tests of Design Solutions","authors":"Aleksandr Voloshin, Said Nukhulov","doi":"10.24160/1993-6982-2023-4-41-49","DOIUrl":"https://doi.org/10.24160/1993-6982-2023-4-41-49","url":null,"abstract":"The substation configuration description language described by the IEC 61850-6 standard is used, among other things, to describe the parameterization of relay protection and automatic control devices. Files described in this language may contain tens of thousands of human-readable and machine-readable text lines. These files are a result of designing and contain design solutions for digital relay protection and automatic control systems, and can be updated at the system adjustment and operation stages. An analysis of how correct such configuration files are at all stages of the life cycle is a labor-consuming task for a person. In view of this circumstance, the authors work on developing a system for automated functional testing of digital relay protection and automatic control systems of substations. The aim of the study is to develop a method for generating reference actuation signals of relay protection devices for automated functional tests of design solutions for digital relay protection systems of substations. The article describes a number of requirements put forward for the method developed, which have been elaborated from an analysis and identification of a number of limitations in existing software solutions for automated testing of digital relay protection and automatic control devices. By using the developed method, it is possible to carry out automated functional tests of design solutions for digital relay protection systems regardless of the manufacturer. The applied regulatory and technical documentation dictating the composition and behavior of relay protection devices is taken into account in terms of rules formalized into a human-machine language. The comparison and choice of the rule formalization technology is given, and the process of formalizing the rules based on which the relay protection reference operation signals are generated is described.","PeriodicalId":499319,"journal":{"name":"Vestnik MÈI","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135207390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}