Енергетика та системи керування
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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.