Енергетика та системи керування (EPECS-2013). – 2013 р.
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Матеріали IV Міжнародної конференції молодих вчених EPECS-2013
У збірнику опубліковано матеріали конференції, присвяченої проблемам у галузі енергетики. Видання призначено для науковців, аспірантів, студентів.
Енергетика та системи керування : матеріали IV Міжнародної конференції молодих вчених EPECS-2013, 21–23 листопада 2013 року, Україна, Львів / Міністерство освіти і науки, молоді та спорту України, Національний університет "Львівська політехніка". – Львів : Видавництво Львівської політехніки, 2013. – 104 с. : іл. – (4-й Міжнародний молодіжний фестиваль науки "Litteris et Artibus"). – Паралельний титульний аркуш англійською.
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Item Application of technology of utilization associated petroleum gas for power generation(Видавництво Львівської політехніки, 2013) Vysotskiy, Andrey V.There are power plants, whose application would be most practical for primary crude oil processing stations. The power plant is intended for generating electricity as well as, if necessary, for using of heating energy. As well as the other power plants under control of the operator’s console, the reception department operates an industrial programmable controller. The controller manages the operation of the discrete and analog input/output to which measuring instruments are connected (flow meters, level meters, temperature sensors, etc.). The number of measuring instruments and actuators, if necessary, is determined by the process diagram of power plant for the oil processing unit. Hence, most active oil and refinery іnterprises are looking for the application of intelligent and integrated in production manufacturing systems of cogeneration in order to meet the customer demands and be the winners in the competitive market in that field. With available technologies and systems in the field of cogeneration and its related technologies, such application for primary crude oil processing is a reality and can meet the need of the enterprises. Today technical mangers are confused with varying equipment that prevail in this field. This article is aimed at overcoming the confusion with the new technologies that have been generated in the past five years. Further, this paper showes that all these new proposals are indeed very important and can be applicable for primary crude oil processing and cogeneration. Finally, this article focuses on latest research developments towards modern cogeneration system for primary crude oil processing stations.Item Аналіз та оцінка впливу шкідливих викидів ТЕС України на навколишнє середовище(Видавництво Львівської політехніки, 2013) Коваленко, Тетяна; Коваленко, ПавлоThe development of science and technology continually affects the growth of human impact on the environment. Especially in our time, the problem of pollution of the atmosphere, lithosphere and hydrosphere and their negative impact on the biosphere, human life and health becomes more and more relevance in the world. Therefore, the analysis of current research and publications concerning the effects of emission of thermal power plants in Ukraine on the environment have been done in this work. The reasons that lead to the pollution of the biosphere were generalized and the ways to overcome this environmental problem were given. The main conclusions of the work were made according to the scientific research.Item Аналіз аварійних режимів роботи вимірювальних трансформаторів струму(Видавництво Львівської політехніки, 2013) Яцейко, Андрій; Ференсович, РоманDisconnecting the secondary circuits from current transformers are accompanied by the occurrence on the terminals of their secondary windings surges which are dangerous for isolation of current transformers, attached to them equipment and life staff. The paper analyzes emergency modes of working two-stage current transformer type TFZM-500 after disconnecting secondary windings its stages. Researches were conducted on created in computer program design scheme of this cascade transformer which allows to model various modes of its working. Results of investigation have theoretical and practical significance for further analysis modes of disconnecting secondary circuits of current transformers in order to create effective and reliable methods of protecting from surges. It is shown a block diagram of current transformer protection system from action of dangerous surges after disconnecting its secondary circuits which based on using microprocessor technology.Item Математичне моделювання температурного режиму потоку газу в системах його обліку при імпульсних режимах роботи(Видавництво Львівської політехніки, 2013) Федоришин, Роман; Комарецький, Олександр; Чура, Мар’янThe mathematical model of the temperature regime of gas flow in a metering system is built based on the law of conservation of energy. Using the developed model the transient processes are simulated and compared to the results of experimental studies. On the basis of verification of the developed model it was defined that the maximum absolute deviation of the simulated values from the experimental results was 0.73 ºC. The developed model provides the possibility to define the systematic error of natural gas flow temperature measurement caused by inertia of the thermometer in pulse regimes of flow. The pulse regime of flow is present in natural gas metering systems installed in boiler houses where the switching on and off of the boiler leads to the pulse regime of gas consumption. Ways to define and eliminate the systematic error of flow temperature measurement caused by inertia of the thermometer in pulse regimes of flow are proposed in this paper in order to improve the accuracy of natural gas metering.Item Умови реалізації цифрових регуляторів на цифрових системах з обмеженою розрядністю(Видавництво Львівської політехніки, 2013) Сольський, Мар’янThe problem of impact of finite-precision data on digital control systems synthesis and practical realization is described. Dependences between the accuracy of elementary first and second order dynamic links coefficients and minimal admissible sampling step were determined and analyzed.Item Визначення відносного діаметра діафрагми оптимальної за точністю вимірювання витрати природного газу(Видавництво Львівської політехніки, 2013) Кузик, Володимир; Чабан, Богдан; Лесовой, ЛеонідThe national literature review showed that the mathematical model for the relative standard diameter of narrowing device calculating because of the introduction of new national standards should be clarified. The components of flowrate measurement error, directly dependent on the design parameters of the standard narrowing devices are found. The optimality criterion for calculating of the structural parameters of the standard narrowing devices for optimal precision flow measurement of natural gas is proved in this paper. An algorithm of calculating of the structural parameters of the standard narrowing devices of differential pressure flowmeter for natural gas measurement, that enhances the accuracy of flowrate measurement by reducing of systematic errors that depend on the design parameters of the standard narrowing devices, was made as well.Item Dynamic simulation of a load system driven by two identical PMDC motors(Видавництво Львівської політехніки, 2013) Atalay, Ahmet Kubilay; Kocabas, Derya Ahmet; Basdogan, SedaIn this study, dynamic simulation of a load system driven by two identical permanent magnet direct current (PMDC) motor is performed by MATLAB / SIMULINK. In the dynamic simulation, two equivalent motors are tandem operated both at same voltage and different voltages in order to drive a mechanical load. The current of each motor, total induced torque and steady state speed of the entire drive system are obtained. It is seen that, when the motors are supplied by the same voltage they share the load equally. On the other hand, if they are operated with different voltages, the motor which is supplied with lower voltage always operates as a generator and the motor which is supplied with higher voltage is overloaded in order to supply the other one and drive the mechanical load.Item Вплив гідродинамічних збурень на точність вимірювання швидкості потоку ультразвуковими витратомірами газу(Видавництво Львівської політехніки, 2013) Роман, Віталій; Матіко, ФедірThe modeling of perturbed velocity profile of turbulent gas flow using computational fluid dynamics method (CFD) is carried out. The algorithm for determining the average velocity along the acoustic path is developed using the results of CFD-modeling. The effect of influence of flow profile distortions produced by the fitting "90° elbow" on the average velocity measurement error is investigated for single channel ultrasonic flowmeter with diametrical acoustic channels. Modeling of such flowmeter is carried out for various angles of the plane of diametrical acoustic channel (0°, 45°, 90° and 135°). The dependence of the relative deviation (error) of average velocity on the angle of acoustic channel and on the distance between the flowmeter and the fitting "90° elbow" is investigated. The angle of acoustic channel of ultrasonic flowmeter that provides the minimum error of flow velocity measurement downstream of fitting "90° elbow" is defined. The distance between the ultrasonic flowmeter and the fitting "90° elbow" is defined to provide the velocity measurement error smaller than 0.5%.Item Алгоритм роботи комбінованої автономно-мережевої системи електроживлення окремого об’єкта(Видавництво Львівської політехніки, 2013) Климко, ВолодимирIn this article an algorithm of work of a combined autonomous and network power supply system of a individual object is considered, and also work of the scheme used in this system is described. For providing the consumer with necessary capacity, it is offered to combine of using of energy of renewable sources, such as wind and solar, and the energy arriving from the centralized network. Use of the electrochemical storage battery as a part of installation for an uninterrupted power supply of object is offered. To management the process of generating of electric power, its distribution between consumers of a certain object, and also optimization of work of elements of installation, the using a controller as a part of a power supply system is offered. The main criterion for the application of the given combined system for ensuring needs of the consumer is direct consumption of the electric energy generated by the wind turbine and the photovoltaic unit. The main goal of this work is improvement an algorithm of work of the combined autonomous and network power system. Relevance of it work consists in using of a new type of the combined power supply system for providing the consumer with qualitative electric energy at any moment.Item The voltage control system of self-excited induction generator(Видавництво Львівської політехніки, 2013) Pushkar, Mykola; Goncharenko, OlexandrThe novel voltage control system for self-excited induction generator (SEIG) is proposed. It is based on TRIACswitched capacitor bank which is controlled according to the proposed algorithm considering the self-excitation borders of SEIG. Such system could be used in stand-alone power generating systems for feeding active and active-inductive load with high requirements to the value of generated voltage. It is given the principle of design and operation of such system, and experimentally verified the performance of this system.Item Механічне демпфування у системі енергоформуючого керування синхронною машиною з постійними магнітами(Видавництво Львівської політехніки, 2013) Білецький, Юрій; Щур, Ігор; Щербовських, СергійFor the control of permanent magnet synchronous motor in electromechanical system an energyshaping control systems have been used. The regulation in such systems is realized by injection of additional damping of current vector projections on dq-axes and some correction coefficient. The energy-shaping control systems with present regulation elements provide worse response compare with classical systems and are hard to be configured. The main aim of this article is to suggest an alternative structure of energyshaping control system without these disadvantages. For this purpose the energy-shaping control system structures with mechanical damping as regulation element are proposed. There are presented the advantages of mechanical damping injection as well. To exam the proposed system work the comparative researches of its work with old structure system work were carried out. So, it might be said that for effective regulation in electromechanical system with permanent magnet synchronous motor the energy-shaping control system can be injected with mechanical damping. Such system provides high response and is simple to configure.Item Role of biomass resources in promotion of renewable energy(Видавництво Львівської політехніки, 2013) Singh, Tejinder; Dhingra, ArvindThe world especially the developing countries are facing an increasing power crunch. The conventional energy resources are fast depleting and there is an urgent need to find out new avenues of energy to cater to this increasing demand. It is here the energy from biomass finds its place. Although we have been using energy from biomass since the time man learned to burn wood for energy but with the growing technological innovations this energy can be harnessed to meet the growing energy demands. On a worldwide scale Biomass contributes about 12% to today's primary energy supply, rising between 40% and 50% in most developing countries. Biomass fuel obtained from purpose-grown energy crops as well as forests and agricultural waste are being used in power plants and it is very competitive in price and quality with fossil fuels. Applying biomass technology is both an environmental and human necessity, whether on a local scale to get rid of slurries, waste and refuses, or on a global scale to reduce carbon dioxide content in the atmosphere and hence reduce global warming. Scientists are busy in developing different ways of converting biomass into a form that meets our energy needs, while making best use of the available energy. In this paper an attempt has been made to project the biomass conversion and the new emerging techniques of harnessing power from biomass and also from the other biofuels such as Bio-oil and Bioethanol. Hence an attempt has been made through different techniques in this paper that in developing country like India, how much emphasis need to be given on such renewable energy sources for preservation of conventional sources of energy.Item Investigation of light intensity and temperature dependency of solar cells electric parameters(Видавництво Львівської політехніки, 2013) Tobnaghi, Davoud Mostafa; Madatov, Rahim; Farhadi, PayamIn this paper, the performance and overview use of solar cells is expressed. The role of temperature, sunlight intensity on the solar cells electric parameters has been studied. Experimental results the amount of solar cell output parameters variations such as maximum output power, open circuit voltage, short circuit current, and fill factor in terms of temperature and light intensity shows. the most significant is the temperature dependence of the voltage which decreases with increasing temperature. Also output current of solar cells is directly proportional to the light intensity. The best performance of solar panels in sunny and cold day has been suggested. Obtained results could lead to optimal use of solar cells.Item Methods of improving the reliability of distribution networks 6-35 kV(Видавництво Львівської політехніки, 2013) Shkrabets, Fedor; Kyrychenko, MarynaThe causes of damage to distribution networks are considered and the main methods for insulation condition monitoring as well as fault detection and location are described.Item Дослідження впливу поворотної заслінки на гідродинамічний режим нафтопроводу(Видавництво Львівської політехніки, 2013) Кріль, Сергій; Кріль, Богдан; Кріль, ОлександрThe article discusses the positive aspects of the using a butterfly valve to control the outlet pressure of the oil pumping station. Also it emphasizes the importance of the pressure control in oil pipeline to ensure its safe operation. The dependence of the differential pressure on the butterfly valve position, which was experimentally obtained in the oil pipelines in operation, is also analyzed in this article. The uneven impact of butterfly valve on the hydrodynamic regime of the main oil pipeline is demonstrated. The article points out the need to change velocity of the butterfly valve rotary especially in the inefficient and too large throttling areas.Item Алгоритм та програмна реалізація декартового множення як елемент побудови моделі гідрогазодинамічних дросельних схем(Видавництво Львівської політехніки, 2013) Грудецький, РоманIn the design of modern technological parameters of transducers having trouble choosing scheme of the converters, which would provide the necessary technical and metrological characteristics of them. One such problem is the lack to date methodologies describe outline of transducers that describe the relevant circuit solutions , with which to perform synthesis and optimization of transducers. Proposed to be used for this set-theoretic concept, extending the number of concepts and operations of set theory. This will formalize the description and modeling scheme of the transducers, and on this basis to develop a theory of synthesis circuit solutions that automate the process of decision-making circuit. For a given or re-synthesized circuit building measuring transducer to explore its functionality and specifications. It is necessary to develop a methodology for modeling of converters and make it algorithmization that will implement the following processes on the computer. The result of research is to develop computer-aided design elements mentioned above transducers.Item Знаходження сталої часу теплової вимірювальної комірки з метою підвищення швидкодії газоаналітичних приладів(Видавництво Львівської політехніки, 2013) Макар, Олег; Кріль, Олександр; Кріль, БогданIn gas analysing equipment heat detectors are widely used for converting thermal physical and mechanical parameters of the gaseous mixture into an electrical signal. Heated by electric current these detectors sense thermal conductivity, heat capacity and project gasous mixture expenditure. Sensitivity and performance velocity are among the main parameters of these detectors determining the irmetrological characteristics. The given paper provides the equation of time constant of the heat measuring cell, common in gas analysing equipment, for the purpose of studying the influence of detectors’ mode changes on the performence velocity of gas analysing equipment.Item Планування виробничих експериментів для багатофакторного дослідження технології сушіння торфу в парових трубчатих сушарках(Видавництво Львівської політехніки, 2013) Кулаковський, Леонід; Алтухов, ЄвгенійThe paper highlights the necessity for planning the experiment in steam pipe dryers of peat for multivariate investigation of the drying process and for further searching power saving regimes of drying. Analysis of plans of experiments allowed to identify the main criteria for the construction plan of the experiment in steam pipe dryer. The basis for the planning of the experiment should take regime maps of tube steam dryers, which provide required quality of a dried peat and changing of control actions carry out in the range of operating conditions. In order to decrease the number of experiments, and also not to rid planning matrix its best features is necessary to develop fractional factorial experiment (FFE) and to identify fractional replica. The optimal experiment’s plan for creating a mathematical model of the drying process is FFE 25-1 with shoulder g=1 and experiments in the center of the plan.Item Новий алгоритм екстремального керування(Видавництво Львівської політехніки, 2013) Турич, ОлегThis article aims to show how inertia of SB affects on a work of proposed extremal control algorithm. Another task is also to create a mathematical and computer model taking into account the dynamics of the solar battery (SB). Also, the continued use of the computer simulation result shall help in the selection maximum power point tracking algorithm for solar battery and applying it to the real using of thisselection, if research will be successful. The many algorithms were developed for maximum power point tracking (MPPT) currently. All these methods are differing to a greater or lesser extent. Their main differences are: the complexity, the need for sensors, speed and system cost, performance, popularity and so on. Therefore, a new algorithm is proposed for implementation which must have adequate computer model of the object – Solar Battery. Some researches was conducted, the basic idea of which was to identify the dynamic properties in SB mode load changes. In the presence of such properties, the initial coordinates (current and voltage) have abrupt changes in load corresponding changes, which can determine the behavior of the object and identify it as a dynamic link. The article presents the results of the algorithm on a computer model taking into account the dynamic properties of SB in graphs.Item Методика прогнозування часової похибки входу транспортного засобу у зону обслуговування радіонавігаційної станції(Видавництво Львівської політехніки, 2013) Шульга, Олександр; Пугач, Микола; Нелюба, ДмитроThe article disclosed Earth's atmosphere model refine method, using the minimum measurement information. Due to heavy density values of atmospheric predictability, at weekly intervals forecasting, time may have significant error. This may result in unstable spacecraft signal reception of ground moving vehicles and breakdown sessions management. There may be non-board equipment operations situations of capture specific information due to a significant deviation of the real spacecraft undersattelite forecast point. In this regard, it is necessary to predict possible longitudinal motion errors (on temporary amendments) prior to the regular measurement cycle current navigation parameters and refinement navigation conditions. These temporary adjustments can be quickly made in targeting the upcoming session and included in the calculation command and program information. Reconciliations of these sites and clarify unknown atmosphere model parameters performed after conversation with the spacecraft.