2019

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1.8 mw rooftop solar photovoltaic power plant
(Національний технічний університет "Харківський політехнічний інститут", 2019) AbuGoukh, Haidar Gafar
Nowadays, renewable energy resources play an important role in replacing conventional fossil fuel energy resources. Photovoltaic energy is one of the very promising renewable energy resources which grew rapidly in the past few years. Renewable energy resources play an important role in electric power generation. There are various renewable resources which is used for electric power generation, such as solar energy, wind energy, geothermal etc. Solar Energy is a good choice for electric power ge nera-tion, since the solar energy is directly converted into electrical energy by solar photovolta ic modules. These modules are made up of silicon cells. When many such cells are connected in series we get a solar PV module. The current rating of the modules increases when the area of the individual cells is increased, and vice versa. When many PV modules are connected in series and parallel com-binations we get a solar PV array, which is suitable for obtaining higher power output. This study aims to design and evaluat e the grid-connected solar photovoltaic roof-top system. The performance of the system was simulated using PVsyst software and the re-sults were analyzed. The analyses of the simulation results show that maximum total energy generation of 329.3 MW h was observed in the month of May and lowest total energy generation of 166.4MWh was observed i n the month of December.The utilization of roof building will be increasing the amount of solar energy and achieving Dubai clean energy strategy 2050 goals which aims to provide seven per cent of Dubai’s power through clean energy by 2020, 25 per cent by 2030 and 75 per cent by 2050.” it will be implemented through Shams Dubai initiative, which aims to encourage building owners to place solar panels on the roofs and link them to t he main network of DEWA.
75 років вищій інженерній освіті моряків в Україні
(НТУ "ХПІ", 2019) Міюсов, М. В.
Analysis of design features of inductive electromagnetic current limiter
(НТУ "ХПІ", 2019) Goncharov, Evgen Viktorovych
The design circuits of an electromagnetic short-circuit current limiter of inductive type with movable armature and moving core are considered. A comparative analysis of the design features of the electromagnetic current limiter with copper or superconducting winding is carried out. The operation principle of the electromagnetic short-circuit current limiter of inductive type with copper or superconducting winding is considered. The peculiarities of operation modes of the electromagnetic short-circuit current limiter of inductive type with copper or superconducting winding are analyzed. Using results of the mathematical modeling of the magnetic system of the electromagnetic short-circuitcurrent limiter by the Finite Element Method in the FEMM software environment, the character of the distribution of the magnetic flux density in the nominal mode and in the current limiting mode is determined, which allows to determine the parameters of the current limiter and design features. In accordance with the design features of the electromagnetic short-circuit current limiter of inductive type, the sequence of calculation of the basic parameters of the magnetic system, taking into account the voltage drop factor, is given. The basic equations of the electric equilibrium of the voltage drop of the electromagnetic short-circuit current limiter of inductive type for nominal mode and short-circuit conditions are given. The use of the design circuit of the electromagnetic short-circuit current limiter with superconducting winding can provide energy-saving in nominal mode. The use of high-temperature superconducting wire due to increased critical parameters will ensure preservation of the superconducting state of the winding in short-circuit mode.
Analytic solution of the differential Maxwell system and its numerical implementation
(НТУ "ХПІ", 2019) Vorobiyenko, Peter Petrovich; Dmitrieva, Irina Yuriyevna
The differential Maxwell equations are solved constructively under the specific requirements in the spatial Cartesian coordinate system. The expressions of the unknown electromagnetic field vector intensities are found explicitly as the solutions of the general wave equation regarding all scalar components of the initially unknown vector field functions. The aforesaid equation is equivalent to the original Maxwell system. The present results are obtained using two new efficient operator analytical methods which application is shown also for the heterogeneous media. The numerical implementation for the particular case of the considered electrodynamic mathematical model is proposed here as well.
Approximate estimates of the temperature state of ceramic nuclear fuel in cylindrical fuel elements and the influence of processes and parameters of a nuclear reactor core
(Національний технічний університет "Харківський політехнічний інститут", 2019) Romashov, Yury; Chibisov, Dmytro
The approximate mathematical model of the temperature state of ceramic nuclear fuels in cylindrical fuel elements was proposed in the form of linear ordinary differential equation and the boundary conditions. The theory of heat conduction and assumptions about the axial symmetry and absence of heat flows along axis of fuel element, which allow to simplify the common equations in cylindrical coordinates, are the basis of the proposed simplified mathematical model for approximate estimating the temperature state of the nuclear fuel. The intensity of volume heat sources in fuel element was taken into account by using the average values corresponding with the heat power and the structural characteristics of a nuclear reactor core. The conception about the heat transfer coefficient was used for modeling interaction between the fuel and the heat carrier. This heat transfer coefficient depends on characteristic sizes and heat conductions of constituted materials of the fuel element and allows to estimate influence of these on the temperature state of the nuclear fuel. The analytical solution for the temperature of a ceramic fuel in cylindrical fuel elements was obtained and was used for researching. It was shown that the heat conductivity of the fuel has significantly influences both the average temperature and the difference between the inner and outer temperatures in the fuel pellet. At the same time, other parameters have significant influence only on the average temperature of the fuel pellet. Due to these, it is necessary to consider the temperature dependence of the thermal conductivities of the materials constituted the fuel elements for more precisely estimations the temperature state of the fuel pellets, which will lead to nonlinear equations will required the numerical methods for their solving.
Assessment of the complex system condition (on the example of an it сompany)
(Національний технічний університет "Харківський політехнічний інститут", 2019) Goloskokov, Alexander; Yakovenko, Artem Anatolievich
The paper considers the problem of estimating the state of the enterprise (on example of the IT company). The problem is presented in the form of two problems. The first problem is the aggregation of the initial information and the second problem is the identification of the state of a complex system. Authors formulated the problem and selected methods for solution of the problem. It is possible to form software for solving research problems.To solve the problem of aggregation of initial data authors used the fuzzy cluster analysis, namely the fuzzy k-means method. A numerical research was carried out and a test case was figured out in the MATLAB environment. In this test case the source data was reduced to a dimensionless form. Thereafter, already reduced to the same scale, the initial attributes were reduced to fuzziness. The results allow to formalize linguistic variables, whi ch are characterized by the term-sets and definition range. The numerical results were approximated by analytical membership functi ons. The solution of the first task allows to generate a set of possible fuzzy reference situations, which reflect the possible state of the system. E ach situation is characterized by the reference informational granule, which contains information about formalized linguistic variables. The second problem was solved by using the method of fuzzy logic in the MATLAB environment. The test case was calculated. In this test case, the search of the situation in which the IT-company is located was performed. At this stage, the current situation belongs to comparison with each reference situation. In this way, authors determined the most similar reference situation to the current situation. An analysis of the resulting situation allows to argue the state of the IT company. The solution of the second task allowed to establish assessment of IT company state. The theoretical and practical results can improve the efficiency of complex system management.
Assessment of the sustainable development: an economical criticism
(Національний технічний університет "Харківський політехнічний інститут", 2019) Savchenko, Olga Igorevna; Ugur, Turan
Until recent years, developing countries believed that they could fulfil the need to be developed by realizing the goal of rapid and stable growth. In addition, in the theories of economics, it offered gradients that the problems such as unemployment, inequality in income distribution, poverty, and environmental destruction would be solved as long as they achieved the goal of economic growth. However, economic growth, unlike expectations, increased inequality in income distribution, poverty of the masses, the destruction of the natural environment and natural resources to eliminate the possibility of long-term growth and the destruction of social peace, such as the alternative costs to bring out, has led to a new understanding of growth and development. This understanding has created the concept of sustainable development, which takes care of the needs of future generations in an effort to meet the economic and social needs of the present population, and which considers the needs of future generations to consume natural and cultural resources. In this paper, it will be analysis sustainable development assessments from economics perspective by using impact analysis briefly on environmental, economic and social effects on sustainable development.
Basic value of complex systems
(НТУ "ХПІ", 2019) Chimshir, V. I.
The nature of the basic value is investigated in the following article. Particular attention is paid to the value’s development in the initial stages of the system’s emergence. As a result of the research it was revealed that the basic value, as an indicator, allows to inspect the state of the system at various stages of its life cycle. The author analyzes the approaches to process research of the basic value formati on of the scientists in technical and economic fields. Studies have shown that considering given problem through the prism of target management one can get organizational forms that have large production potential. At the same time the obtained forms have the property of combining technical and social systems being in a stable state. The basic value of such complex systems is to be based on its internal needs. The basic value of the socio-technical system was based on a certain state function the increment of which in any process performed by the system in a closed environment is equal to the sum of the effects on the system through resources leading it to the transition from the initial state to the final one. Determining the basic value a number of difficulties were also noted one of which is an increase of the error of the parameters defining the location of the system when it is at the stability limit. The basic value is investigated as the primary component of the new socio-technical system as well as the nature of the transition processes of the system in accordance to the use of internal and external resources. It is determined that internal and external resources determine the potential of the system and the possible dynamics of its development. One of the methods for measuring the basic value of the system is defined, in which the isolated system changes its state through resource exchange. One of the conclusions shows that the basic value does not depend on the choice of the previous state but depends on the resources that tranport it into this state.
CFD підхід для аналізу характеристик потоку високонапірної радіально-осьової гідротурбіни
(Національний технічний університет "Харківський політехнічний інститут", 2019) Миронов, Костянтин Анатолійович; Олексенко, Юлія Юріївна; Миронов, Вадим Костянтинович
З ростом обчислювальної механіки віртуальні гідравлічні машини стають все більш реалістичними, дають можливість визначити незначні деталі потоку, що в свою чергу неможливо отримати при тестуванні моделей. В данній роботі проведено 3D турбулентний аналіз реального потоку в радіально-осьовій гідравлічній турбіні при трьох відкриттях направляючого апарату та різній швидкості обертання за допомогою програмного забезпечення для обчислювальної динаміки рідин (CFD) Ansys CFX. Обчислюються для отримання характеристик потоку середні значення параметрів потоку, такі як швидкість і кути потоку на вході і на виході з робочого колеса, направляючого апарату і статору. Для поліпшення енергетичних показників на попередньому етапі проектування гідротурбіни проводиться чисельне моделювання потоку. Даний підхід CFD знижує витрати і час в порівнянні з експериментальними підходом і дає можливість удосконалити і аналізувати показники турбіни і її конструкцію до моменту виготовлення моделі. Розрахунковий комплекс програм надає можливість побачити картину розподілу тиску, поле векторів швидкості і руху частинок рідини для обґрунтування та аналізу результатів. Наведені результати розрахункового дослідження підтверджують, що гідравлічний коефіцієнт корисної дії гідравлічної турбіни в значній мірі залежить від втрат в напрямному апараті і робочому колесі і означає, що саме цим елементам варто приділяти найбільші увагу, їх конструкції та узгодженню потоку в них. Отримані розрахункові дані відповідають відомим раніше експериментальним рекомендаціям для високонапірної радіально-осьової гідротурбіни.
Combinatorial optimization under uncertainty and formal models of expert estimation
(НТУ "ХПІ", 2019) Pavlov, Alexander Anatolievich
Previously, the author formalized the concepts of uncertainty, compromise solution, compromise criteria and conditions for a quite general class of combinatorial optimization problems. The functional of the class’ problems contains linear convolution of weights and arbitrary numerical characteristics of a feasible solution. It was shown that the efficiency of the presented algorithms for the uncertainty resolution is largely determined by the efficiency of solving the combinatorial optimization problem in a deterministic formulation. A part of the formulated compromise criteri a and conditions uses expert weights. Previously, the author and his disciples also formulated combinatorial optimization models, optimality criteria, criteria for decisions’ consistency. The models allow to evaluate and justify the degree of stability and reliability of the estimated values of empirical coefficients using a formally ill-conditioned empirical pairwise comparison matrix of arbitrary dimension. The matrix may contain zero elements. The theoretical research and statistical experiments allowed to choose the most efficient of these optimization models. In this article, on the base of earlier results by the author and his disciples, we formalize and substantiate the efficiency of the proposed sequential procedure for expert estimation of weights that determine compromise criteria and conditions. The procedure is an integral part of the algorithm introduced by the author to solve combinatorial optimization problems under uncertainty of the mentioned class. We give unified algorithm for efficient uncertainty resolution that includes original and efficient formal procedure for expert coefficients’ estimation using empirical matrices of pairwise comparisons.
Computer-integrated components of the automated decision-making support system for operational and maintenance personnel of nuclear power plant units with WWER
(Національний технічний університет "Харківський політехнічний інститут", 2019) Yefimov, Аleksandr Vyacheslavovych; Yesypenko, Tetyana Oleksiivna; Harkusha, Tetyana Anatoliivna; Kavertsev, Valery Leonidovich ; Berkutova, Tetyana Ivanivna
The purpose of this article is to describe the results of the research aimed at developing computer-integrated components of one of the ADMSS variants for operational and maintenance personnel of NPP units according to the criterion of technical and economic efficiency, taking into account the diagnostics of the technical equipment state based on the simulation model describing by means of up-to-date mathematical methods the technological processes in the main and auxiliary equipment of power units using up-to-date mathematical methods at the level of detailing, corresponding to their principle and deployed thermal schemes. The results of studies aimed at the development of computer-integrated components of the automated decision-making support system (ADMSS) for operational and maintenance personnel of NPP units by the criterion of technical and economic efficiency, taking into account the diagnostics of the state of the power unit equipment, are presented. The general structure of the software package interaction for the analysis of the performance and parameter diagnostics of NPP units with WWER has been developed. When creating the software package, the integrated programming environment Microsoft Visual Studios was used. The structure of the program block for the parameter diagnostics of the equipment of nuclear power units is presented. The main types of problems arising during the operation of NPP units with WWER, that can be solved with the help of the developed ADMSS are considered, and a form for presenting the results to the operational and maintenance personnel of power units is proposed. Developed on the basis of the described computer-integrated components, the automated decision-making support system for the operational and maintenance personnel of NPP power units can be used to solve a wide range of problems arising in the practice of short-, medium- and long-term control of the operation modes of power unit systems and equipment, including obtaining operational (energy) characteristics of power unit systems and equipment, optimizing operation modes and parameters, diagnosing and forecasting technical state of power equipment, predicting the amount of electrical and thermal energy generated by a power unit, as well as optimizing NPP repair cycles.
Conditions for prevention of water hammers at start-up of emergency feed pumps with a steam driver of nuclear power plants
(Національний технічний університет "Харківський політехнічний інститут", 2019) Skalozubov, Volodymyr Ivanovich; Spinov, Vladislav Mykhailovich; Spinov, Dmitriy Vladislavovich; Pirkovskiy, Denis Sergeevich; Gablaya, Taisiya Vladimirovna
A promising approach to accident management in nuclear power plants with a complete loss of long-term power supply is an emergency feed pump with a steam driver from a steam generator. The main advantages of this approach in relation to the known systems of passive heat removal with natural circulation are the fundamental possibility of fully compensating for the failure of design safety systems with electric pumps, as well as the absence of the need to remove the safety system elements to a greater height beyond the containment / container. However, the use of steam driven emergency pumps requires a deep study of their reliability. One such issue is the qualification of reliability when starting an emergency pump with a steam driver. An original method for modeling the conditions for the occurrence of a water hammer when starting a steam-driven pump is proposed. The conditions for the prevention of water hammer due to the inertia of the pressure-flow characteristics of emergency feed pumps with a steam driver from the steam generator are determined. The results obtained can be used in the design of emergency feed pumps with a steam driver from a steam generator subject to additional experimental qualifications.
Construction of discontinuous interlineation polynomial splines for functions of two variables
(НТУ "ХПІ", 2019) Pershyna, Iuliia Igorivna; Tokmakova, Iryna Anatoliyivna; Dumych, Yegor Andreevich
The article suggests a general method for constructing discontinuous interlineation polynomial splines, which, as a partial case, include discontinuous and continuously differentiable splines. The theorems on interlineation and approximation properties of such discontinuous structures are formulated and proved. On the basis of the constructed discontinuous splines, a method for restoration of functions of two variables with first kind discontinuities is created. The theorems on the error of the approximation of discontinuous functions by the constructed discontinuous interlineation splines are proved. Examples are given.
Decision-making specialities in the light of corporate social responsibility
(Національний технічний університет "Харківський політехнічний інститут", 2019) Bakó, Tamás
Company decision-makers increasingly have to confront with the expectations of their closer or extended community, also that of their environment in connection with the consequences of their business-decisions. On the other hand, they must represent the interests of their proprietors and must also sustain profitable economy. The author reviews those factors which have a significant impact on socially responsible decision-making process, concerning the decision-makers, the company and the outer environment. The author answers to the question of what the specialities of such decisions are and in what direction the attitude of economic entities develop, concerning socially responsible operation. The author proved that corporate social responsibility (CSR in short form) manifests itself in a growing and expanding measure in the activities of corporations and business structures, on the one hand, as an expectation in connection with their courses, on the other hand, such a factor if fai ls, can make long-term competitiveness worse. Decisions related to CSR are strategic decisions, so they are made at the highest level. The personality, leadership style and self-assessment of the decision maker play a decisive role in the process of the influence of external expectations regarding CSR on organizational decisions. In addition, the size of the company, the regional location, the surrounding national culture, the social system and traditions also have a significant influence on socially responsible decisions. The described article/presentation/study was carried out as part of the EFOP-3.6.1-16-00011 “Younger and Renewing University – Innovative Knowledge City – institutional development of the University of Miskolc aiming at intelligent specialisation” project implemented in the frame work of the Szechenyi 2020 program. The realization of this project is supported by the European Union, co-financed by the European Social Fund.
Dependence of prognosis and filtration failure on different values of parameters for some classes of non-stationary random sequences
(НТУ "ХПІ", 2019) Cheremskaya, Nadezhda Valentinovna
The article continues the study of estimates of random functions at a future moment of time, linear with respect to the values of pre-histories of processes. The article considers the dependence of the mean square of the forecast error of a random sequence on the last value at different values of the parameters. For non-stationary random sequences, even with correlation functions of the simplest form, such studies haven’t been conducted. To obtain representations of correlation functions, a Hilbert approach is used to calculate correlation functions as scalar products in the corresponding Hilbert space. Investigations of the dependence of the mean square of the prediction error of a random sequence on the last value at various values of the parameters discussed in the article can be used to simulate filtration and prognosis processes in real systems in the case of non-stationary random signals.
Deterioration of XLPE insulation in high voltage cable systems and testing of quality by applying pulses of high voltage
(НТУ "ХПІ", 2019) Kostiukov, I. O.
The wide spreading of energy distribution power cable lines made by means of applying cables with insulation made of cross-linked polyethylene usually is associated with a significant number of advantages in terms of better technical performance that such cables have in comparison with traditional cables with paper-impregnated insulation. Nevertheless, the necessity to ensure a sufficient level of production quality, as well as the requirements for increasing the operating time of power cable lines, make it urgent to develop insulation quality control methods, including control methods which imply applying of testing impulses that simulate overvoltages that occur in power systems due to lightning strikes. The other aspect of this problemis the necessity of the elaboration of physical models for the description of deterioration of XLPE insulation of power cables under the impact of various external factors. For recent years the problem of testing XLPE insulation by high voltage pulses, similarly to the problem of elaboration of physical models for the description of deterioration of XLPE insulation, have been considered by many authors. This paper gives a brief review of some main recent research that have been focused on the problem of endurance and aging of XLPE insulation due to overvoltage caused by various reasons. The main scope was focused on the problem of testing the endurance of XLPE insulation to the voltage pulses that imitate overvoltage due to lightning strikes. Some of the theories of aging of dielectric materials under the impact of impulse and alternating electrical fields and the influence of these factors on lifetime of dielectric materials have also been discussed.
Development of a database structure for storing models for determinated alphabetes classes recognition based on the set of heterogeneous characteristic
(Національний технічний університет "Харківський політехнічний інститут", 2019) Dvukhglavov, Dmytro Eduardovych; Riabukha, Tatiana Olegivna
The objects and situations recognition is important problem in such areas as the definition of the types of air objects according to various sources of information, diagnosis of patients on the results of the survey and analysis, diagnostics of different equipment or technic types. Under the recognition refers to the process of obtaining the initial information about the affiliation of each studied element to a class based on analyze of the incoming information about studied elements of the environment, using methods to transform input data environment into output. The paper presents a model of the recognition process, which is characterized by the decision making of the class object based on the analysis of a set of quantitative and qualitative characteristics of which information can be obtained from various sources. The article presents a formalized settheoretic model of the recognition process. According to the model, to attribute an object or situation to a certain class, it is necessary to define a set of feature groups of different types that allow to identify objects (situations) of a particular class. To perform recognition process experts based on experience or on the basis of statistical data must define a fuzzy affiliation function of the object of observation to each class with a set of values [0,1]. In the article shown represen tation of such function for quantitative characteristic in the form of a histogram. For qualitative attributes determined own values for each value. The new result of researches is a data structure for storing of the recognition process model, which allows to store together diverse characteristics and affiliation functions of different types at the same database tables. The proposed structure can be used in the process of the development of recognition systems software. It should be noted that will provide increased reliability of data storage by reducing the components of the database structure but also increased the complexity of the procedures and algorithms for saving and selecting the data.
Development of a fatty filler recipe for a new type of wafer products
(НТУ "ХПІ", 2019) Polyvanov, Yehor Andriyovych
The article gives an opportunity to develop the technology of fatty filling for waffles and low-calorie wafers by replacing sugar with a mixture of sweet extracts from the leaves of stevia with erythritol. The expediency of regulating the amount of dry matter due to the introduction of dry skim milk whey has been proved. The whey is a raw material component that further enriches the finished product on minerals and vitamins that are healthy for the human body. The possibility of additional introduction of of beta-carotene, as a dye and ascorbic acid, as a stabilizer of fatty wafer fillings has been investigated. In order to improve the quality and safety of finished products, the possibility of using in the technology of fatty fillings for wafer products a new type of confectionery fat of domestic production "Fettifil" has been experimentally confirmed.
Development of molded jelly marmelad technology with the introduction of food additive "Magnetofood"
(НТУ "ХПІ", 2019) Tsykhanovska, Iryna
Lack of domestic raw materials, a significant portion of imported high-cost ingredients and increasing competitiveness make manufacturers look for new technological solutions in order to improve the consumer properties of marmalade products. A promising trend in the field of jelly and marmalade products is the creation of products with high quality and long shelf life. For this purpose various food additives, i.e. improvers, are used in jelly marmalade technology. As an improver of shaped jelly marmalade, we have developed and proposed "Magnetofood" food additive, which is nanopowder with a particle size of (70–80) nm. "Magnetofood" is a food additive with high functional and technological potential. "Magnetofood" additive can independently generate structural and mechanical properties of jelly masses, and also it can influence the gelling agent by entering into chemical and electrostatic interactions with it. Therefore the "Magnetofood" food additive can simultaneously affect several technological properties in the food jelly system: to be a stabilizer, a thickener and a gelling agent. Due to Fe (II), nanosize, developed active surface, bacteriostatic character, high thermal stability, "Magnetofood" has reducing, antioxidant, antimicrobial, sorbing, complexable, emulsifying, moisture-retaining, fat-retaining, water-binding, stabilizing, and structuring properties. It makes possible to recommend "Magnetofood" as an additive of complex action to improve the quality and extend the shelf life of shaped jelly marmalade. The influence of "Magnetofood" food additive on organoleptic, physical and chemical, microbiological parameters of test samples of agar- and pectin-based shaped jelly marmalade has been studied.
Distance learning peculiarities at colleges in Ukraine
(НТУ "ХПІ", 2019) Zotyeva, Galyna; Vyrsta, Yaroslasv
The problem of distance learning implementation at colleges in Ukraine is considered. The relevance of the article is in the need of distance learning and use of the opportunities offered by that means of teaching. Distance learning main aspects, which create the necessary background for scientific achievements are systematized and analyzed in the article. Conceptual ideas of distance education in colleges and further perspectives for the development information and communication technologies in the distance education are investigated. The basis of the diagnosis and monitoring of the quality of education are curricula, programs, the content of which is set out by academic disciplines. The system of management of students in the conditions of distance learning implements the laws underlying the organization of the educational process.