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TECHNICAL UNIVERSITY - SOFIA: Recent submissions

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Title: Methods for numerical simulation of three – dimensional turbulent flows Author: Stankov, Petar; Станков, Петър Date: 1995 Abstract: The paper presents an analysis of the methods of simulating turbulent flows of practical importance. An assessment of Direct Numerical Simulation, Large Eddy Simulation and Simulation by Turbulence Transport models is made concerning the possibility of predicting three-dimensional turbulent flows. The analysis is made in view of present and ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Numerical prediction of comfort and ventilation efficiency in ventilated rooms Author: Denev, Yordan A; Денев, Йордан А.; Stankov, Petar; Станков, Петър Date: 1995 Abstract: The paper presents investigation of comfort and ventilation efficiency in a typically chemical laboratory room with two fume cupboards. The investigation is based on the detailed results obtained from the numerical solution of a system of seven partial differential equations on a numerical grid of 245000 points. The assessment of comfort ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Диапазон на регулиране на дебита при бутални дозиращи помпи Author: Симов, Симеон Теофилов; Кичев, Вълко Маринов; Обретенов, Валентин Славов; Simov, Simeon Teofilov; Obretenov, Valentin Slavov; Kichev, Valko Marinov Date: 1995 Abstract: The range and accuracy of controlling the flow rate of metering limps are of special interest as concerns the industrial applications of this type of pumps. The design solutions known so far provide a range of controlling the flow rate from 30% to 100% of the rated flow rate. Another solution with considerably widened range of controlling ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Определяне на КПД. на водни турбини тип Пелтон от ВЕЦ „Пещера“ Author: Обретенов, Валентин Славов; Кичев, Вълко Маринов; Симов, Симеон Теофилов; Obretenov, Valentin Slavov; Kichev, Valko Marinov; Simov, Simeon Teofilov Date: 1995 Abstract: The paper presents the results of experiments made with Pelson water turbines operating at HG1 at PESHTERA HPS (Hydroelectric Power Station). Experiments were made with the aim to determine the efficiency of .the two turbines before and after the modernization of impellers and regulating system carried out by Sulzer (Switzerland). Measurements ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Върху задачата за ососиметрично потенциално течение в тръба Author: Варсамов, Кирил Георгиев; Varsamov, Kiril Georgiev Date: 1995 Abstract: Two methods for analysis of axisymmetric potential flow in duct are discussed in this paper, namely the method of Amromin and Ivanov (1975) and the one of Varsatnov and Haimov (1978). On the basis of identical theoretical model (steady potential flow of an incompressible fluid) and similar techniques of reducing the boundary value problems ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Система за компенсация на реактивните товари в съответствие с изискванията на новата cosȹ тарифа Date: 1995 Abstract: This paper presents from schemetechnical point of view the principles of reactive loads control by means of microprocessor regulator of reactive power criterion and additional controllers for capacitor batteries control. There are present different cases for compensation of centralized and uncentralized distributed compensated powers in ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Изчисление на загубите на енергия в електрическите мрежи по данни от телеизмерване Author: Боцов, Марин Николов; Botsov, Marin Nikolov Date: 1995 Abstract: The teleirlfonnation in our power system can't be used directly for calculation of energy losses. In this paper is given method for calculation of missing powers in branches and minimization of mismathes. By this method computer program is realized It is tested by real data from network 110 KV in district Gorna Oriahovitsa. Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Съвременен информационен подход при изчисляване на загубите на енергия в електрическите мрежи 100 kv Author: Захариев, Васил Тодоров; Боцов, Марин Николов; Zahariev, Vasil Todorov; Botsov, Marin Nikolov Date: 1995 Abstract: In this a new information report is given relating the calculation of the loses of energy in electrical networks. It is based on information from telemetering or processing of real power diagrams data. By this method computer program is realised, used for calculation of loses of the energy in real electrical networks. Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Метод за определяне на скоростната характеристика на системата секционен изолатор – токоснемател Author: Бакалов, Здравко Станчев; Bakalov, Zdravko Stanchev Date: 1995 Abstract: In the paper are described the developed analytical method for determination of the speed characteristic of the section insulator-current collector system as well as methods for determinated of the basic magnitudes, which are used for the calculations and at the same time have been determined the design and the maximum admissible running ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Специфични проблеми на заземяване на съоръженията по електрифицираните жп участъци Author: Вичева, Нели Тодорова; Андрова, Наталия Иванова; Андреев, Радослав Владимиров; Vicheva, Neli Todorova; Androva, Natalia Ivanova; Andreev, Radoslav Vladimirov Date: 1995 Abstract: In the paper has been examined the equipment earthing around the electrified railway sections and have been analysed the problems that appear in terms of assuring normal operation-of the relay protection, .man steely at work, as well as compatibility and correct operation of the mil circuits of the safety installations. At the same time are ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Входен преобразовател за цифрова земна защита Author: Цолов, Ангел Белчев; Малчев, Константин Малчев; Миланов, Милан Петров; Tsolov, Angel Belchev; Malchev, Konstantin Malchev; Вичев, Станимир Трифонов; Vichev, Stanimir Trifonov Date: 1995 Abstract: This paper reviews a laboratory model of a input processing unit for multi-criteria ears fault protection in isolated or high impedance grounded distribution networks. The earth-faults are detected by the transient components of the zero current and zero voltage sequences and by-relatively comparing the-level of the base harmonics and the ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Относно прилагането на строги и опростени математически модели за определяне характеристиките на заземителни устройства Author: Иванов, Иван Василев; Йорданов, Румен Стоянов; Ivanov, Ivan Vasilev; Yordanov, Rumen Stoyanov Date: 1995 Abstract: Sizing the grounding devices (GD) when projecting is a very important engineer task which can be solved by application of different methods. Some are very simplified based only on the size and kind of the GD. Other popular methods considering the electric field in the soil allow taking into consideration nearly all the factors which influence ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Система за определяне на мястото на повреди в реално време Author: Наков, Петър Митрофанов; Nakov, Petar Mitrofanov Date: 1995 Abstract: The real time foul[ locations system is designed. The fault is located by registration of wave process as a result of fault occur and mathematical procedure. The result is displayed as a picture to dispatches computer, Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Анкетно проучване на консумацията на електроенергия за осветление на домакинствата в стараната Author: Янева, Николина Иванова; Yaneva, Nikolina Ivanova; Иванов, Захари Александров; Ivanov, Zahari Alexsandrov Date: 1995 Abstract: Inquiry investigation and experimental measurements were carried out with the aim to define the total energy consumption for lighting. The inquiry technology, the methodology for the data processing, the analysis of the results and conclusions are presented in the report. An analitical dependence is received between the energy consumption ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Възможности за повишаване на енергийната ефективност на уличните осветителни уредби. Технически средства за рационално управление Author: Пачаманов, Ангел Саракинов; Pachamanov, Angel Sarakinov; Василев, Николай Иванов; Vasilev, Nickolay Ivanov Date: 1995 Abstract: The report evaluates the basic approaches for encasing of electric power effi-ciency of street lighting — utilization of energy efficient lighting sources, application of lighting sources with optimized optic systems, related on the type of the street and the road surface, realization of night and half-night regime of the work of the lighting ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Интерактивен програмен комплекс за въвеждане на началната информация при моделиране на преходни процеси в електроенергийните системи Author: Джагаров, Николай; Dzhagarov, Nikolay Date: 1995 Abstract: Резултатите от моделирането на преходните електромеханични процеси в електроенергийните системи (ЕЕС) по пълните уравнения на Порк се използват при проектирането и експлоатацията на системите. Една от важните здачи при създавнето на програмнта система за моделиране е автоматизацията на въвеждането на началнта информация. Програмната система ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Използване на обобщен подход при определяне компонентите на пълната мощност в електроенергийните системи Author: Петков, П.; Парушев, Пл.; Георгиев, Г.; Чиков, В.; Chikov, V.; Georgiev, G.; Parushev, Pl. Date: 1995 Abstract: В настоящия доклад се представя един обобщен подход свързан с определяне на компонентите на пълната мощност в условията на несиметрия и висши хармонии в ЕЕС (електроенергийните системи), основаващ се на теорията на изобразяващия вектор. Представените сведения в доклада представляват продължение и прецизиране на резултатите поместени в ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Тенденции в развитието на микро – водно електрически централи в развиващите се страни Author: Сотиров, Димитър Кирилов; Турялай, Мохамед Шариф; Sotirov, Dimitar Kirilov; Turyalay, Mohamed Sharif Date: 1995 Abstract: This paper take up problems for future development of electrical energy in the third world. The priorities and the faults qf electrical energy production. Recomendations about manner of its production. Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Дефиниране на маржиналните разходи Author: Стойчев, Димитър Димов; Петканчин, Лазар; Petkanchin, Lazar; Stoychev, Dimitar Dimov Date: 1995 Abstract: In this paper authors analyse the internal essence of electricity' marginal costs in theoretical and practical aspects. The article consider some important issues of marginal Costs' grounding and definition. The authors generate some ways to form appropriate simple, but correct procedures of marginal costs classification, data collecting, ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Маржиналние разходи в практиката Author: Стойчев, Димитър Димов; Stoychev, Dimitar Dimov; Петканчин, Лазар; Petkanchin, Lazar Date: 1995 Abstract: In this paper authors analyse the internal essence of electricity' marginal costs in more practical aspects. The article consider some important issues of marginal costs' evaluation. The authors generate some ways to form appropriate simple, but correct procedures of marginal costs aggregating and desegregating, modelling and manipulation. ... Library:
TECHNICAL UNIVERSITY - SOFIA