I. Възобновяеми
енергийни източници и опазване на околната среда
Оптимална
интеграция на разпределени за пасяващи енергията
устройства и малки генератори в автономна система с възобновяеми енергийни източници
Относно
характеристиките на хладилник работещ със слънчева абсорбция
Експериментално
изследване на загубите в двойно захранван асинхронен
генератор
Значението
на биоетанола от второ
поколение за стабилна енергийна независимост
III. Енергийна ефективност и опазване на околната среда
Сграда с близка до нулата енергийна
консумация: изследване на
случай на жилищен блок
Влияние
на покритията върху топлинните характеристики на
стъклопакети
Изчисляване
характеристиките на процеса на аерация на води в нестационарни
условия
Николае Баран, Александру-Сорин Патулеа,
Йонела-Михаела Калусару
73-78
ОПТИМАЛНА ИНТЕГРАЦИЯ НА РАЗПРЕДЕЛЕНИ ЗАПАСЯВАЩИ ЕНЕРГИЯТА УСТРОЙСТВА И МАЛКИ ГЕНЕРАТОРИ В АВТОНОМНА СИСТЕМА С ВЪЗОБНОВЯЕМИ ЕНЕРГИЙНИ ИЗТОЧНИЦИ
Ву
Танг, Ксавие Пивер, Кристиян Шефер
OPTIMAL INTEGRATION OF DISTRIBUTED
ENERGY STORAGE AND SMALL GENERATORS INTO AN ISLANDED
MICROGRID
WITH RENEWABLE SOURCE
Thang Vu, Xavier Le
Pivert, Christian Schaeffer
Abstract: The purpose is to study how best to integrate distributed energy storage and small thermal generators in a Microgrid mainly powered by renewable sources. Optimal placing and capacity sharing of distributed energy storage helps to reduce Joule losses and voltage drops. Small generators give same advantages at optimal location. Optimal capacity sharing of Distributed energy storage is based on Droop mode control of specific inverter. Storage units are guided to behave homogenously to have the same evolution of State of Charge, so the same life cycle. By minimizing the Joule losses, the decentralization of storage allows to reduce the conductor section or the size of renewable power sources at design phase. For existed grid, it could delay distribution grid’s upgrade investment. It should be therefore financially interesting.
Keywords: Distributed Energy Storage, Optimal placing, Droop mode
Gilles Notton, Christophe Paoli, Siyana Vasileva, Lilyana Ivanova, Marie Laure Nivet and Ludmil Stoyanov
(PDF 1778k)Abstract: Global irradiation on tilted planes is required in all engineering calculations for solar systems. Various methodologies are compared in view to obtain these data from measured horizontal global solar irradiation using empirical or semi-physical models and Artificial Neural Network (ANN).
Keywords: Solar radiation estimation, ANN method, conventional method.
Emna Berrich, Ali Fellah, Ammar Ben Brahim, Fethi Aloui, Michel Feidt
(PDF 113k)Abstract: Solar absorption refrigerator's performances are analysed by a conceptual optimization. The simulation is based on hierarchical decomposition, on the principles of the endoreversibility, respectively of the exoreversibility of the solar absorption refrigerators. Optimization is carried out by adopting the method of Lagrange multipliers. This methodology was been applied to absorption cycle composed of a solar concentrator (hot source), a thermal solar converter (thermal engine 1), an intermediate source, a cold source and four main elements: a generator, an absorber, a condenser and an evaporator. The generator and the absorber constitute a thermal engine ET2 and the whole condenser evaporator forms the thermal receptor RT. The parameterization of the installation comprises fluxes and powers and the temperatures that reign in the thermal machine compartments. This made it possible to get out two equation systems which guarantee the coupling of general optimal performance characteristics of a simple effect solar absorption cycle. The functional and conceptual characteristics are studied. In particular, the effect of the external sources temperatures on the performances is discussed. These results are interesting in absorption machine’s conception viewpoint. They encourage studies in an irreversible way.
Keywords: Absorption refrigerator, Solar energy, Optimization, Hierarchical decomposition, Endoreversibility, Exoreversibility.
ИЗСЛЕДВАНЕ НА
РЕАЛИЗИРУЕМОСТТА ЗА ХИБРИДИЗАЦИЯ НА МАЛКА ДИЗЕЛОВА
ЕЛЕКТРОСТАНЦИЯ И ФОТОВОЛТАИЧНА ЕНЕРГИЙНА СИСТЕМА
Саид
Диаф, Жил Нотон
FEASIBILITY STUDY
OF HYBRIDATION OF MINI DIESEL POWER STATIONS WITH
PHOTOVOLTAIC ENERGY SYSTEMS
Abstract:.
Nowadays, the majority of diesel power stations located
in the southern part of Algeria operate under difficult
conditions and their diesel generators don't operate at
nominal regime. The hybridation of micro diesel power stations
with photovoltaic(PV) energy system permits to reduce the
operation time of diesel generators and consequently reduces
the fuel consumption. This paper presents a technical economic
of hybrid photovoltaic–diesel–battery system. The objective of
this work consists on developing a decision-making tool that
allows the opportunity evaluation for combining micro diesel
power stations with PV energy system.
This decision making tool is based on
• establishing of technical and economic
models of the system’s components
• optimization of system sizing
The simulation results related to this study will be presented
and analyzed in this paper.
Keywords: hybrid system, diesel generator, optimum system sizing, loss of power load probability, levelized cost of energy
ЕКСПЕРИМЕНТАЛНО ИЗСЛЕДВАНЕ НА ЗАГУБИТЕ В ДВОЙНО ЗАХРАНВАН АСИНХРОНЕН ГЕНЕРАТОР
Владимир
Лазаров, Захари Зарков, Людмил Стоянов
EXPERIMENTAL STUDY OF LOSSES IN
DOUBLY-FED INDUCTION GENERATOR
Vladimir Lazarov, Zahari
Zarkov and Ludmil Stoyanov
Abstract: This paper presents an experimental study of the losses doubly-fed induction generator (DFIG) for wind energy conversion system. The experiments were performed on a laboratory test bench. The losses in the components of the system - electronic converters, transformer and induction machine - are determined by measuring the power in different system points and by making the appropriate calculations. Quanti¬tative assess¬ment of the distribution of losses and of the overall system efficiency is also carried out. The results can serve to validate the theoretical models and assumptions. Although the study is designed for a small power machine, it makes it possible to outline certain trends and connections between the losses and the energy flows in sys¬tems with DFIG.
Keywords: DFIG, losses, wind generator
ПОДОБРЯВАНЕ НА ПРОИЗВОДСТВОТО НА БИОЕТАНОЛ ОТ ДЪРВЕСНА БИОМАСА КАТО ПОДХОДЯЩО АЛТЕРНАТИВНО ГОРИВО ЗА ДВИГАТЕЛИ С ВЪТРЕШНО ГОРЕНЕ
Лауренциу
Фара, Александру-Кристиан Раковица, Георге Никулае
Laurentiu Fara, Alexandru-Cristian
Racovitză and Gheorghe Niculae
Abstract: Bio-ethanol has been proved to be a better alternative fuel to SI Engines for reasons concerning classic fuel economy, lower emissions’ levels and promising industrial obtaining methods by using chemical and biological means. Bio-ethanol is the main product to be achieved through the fermentation of the sugar-compounds that are themselves obtained from wooden biomass. The primary biomass source comes from a special poplar clones harvested from three different zones of Romania in order to offer a comparison basis in terms of biomass production efficiency. Among all the known industrial fermentation methods of the sweet compounds extracted from biomass, this paper reveals a new and more efficient process given by the enzymatic fermentation.
Keywords: Bio-ethanol, wooden biomass, enzymatic fermentation, efficiency, low emissions.
ЗНАЧЕНИЕTO НА БИОЕТАНОЛA
ОТ ВТОРО ПОКОЛЕНИЕ ЗА СТАБИЛНА ЕНЕРГИЙНА НЕЗАВИСИМОСТ
Кънчо Лахчев
THE CONTRIBUTION OF SECOND GENERATION
BIOETHANOL TO SUSTAINABLE ENERGY INDEPENDENCE
Kantcho
Lahtchev
Abstract. In this review the basic
approaches for development and improvement of bioethanol
industry, its perspectives and problems encounter are
summarized. Bioethanol produced from plant biomass
by biochemical method (second generation bioethanol) is
object of special attention. The perspectives and quality
of this biofuel are compared with those of bioethanol
produced from starch feedstock (first generation
bioethanol). The advantages as well as problems concerning
manufacturing and commercialization of second generation
bioethanol are discussed also. It is pointed on the
necessity of global approach to develop and stimulate such
industry. The initial steps of commercialization of second
generation bioethanol as well as future impacts of such
industry on sustainability and environmental are presented
also.
Key
words:
bioethanol, commercialization, sustainability, environment
КРАТЪК
ПРЕГЛЕД НА ТЕХНОЛОГИИТЕ ЗА ГАЗИФИКАЦИЯ НА БИОМАСА, ТЯХНОТО
ПРИЛОЖЕНИЕ И ПОТЕНЦИАЛЕН РИСК
ПО ОТНОШЕНИЕ НА СИГУРНОСТТА И ОКОЛНАТА СРЕДА
Петър Калейчев,
Костадин Белев, Иван Иванов
BRIEF REVIEW OF
GASIFICATION BIOMASS TECHNOLOGIES, THEIR APPLICATION AND
POTENTIAL RISK REGARDING
THE SAFETY AND ENVIRONMENT
Petar
Kaleychev, Kostadin Belev, Ivan Ivanov
Abstract: Biomass gasification as technology for energy production has recently significant development and perspectives for further increasingly application. A number of institutes in the EU work towards establishing a unified approach to the risk assessment of technology for gasification of biomass. The report takes a variant of how this approach can be applied to research of concrete installations. Covers all possible aspects and serves as an addition to the existing information. The report presents initial results up by research into installations for the gasification of biomass, which are intended to show their position on the safety and impact on the environment. They are a basis for future research focused on the formation of recommendations and proposals on specific aspects of the operation of these facilities.
Keywords: gasification, biomass, risk assessment, safety, environment
СГРАДА С БЛИЗКА ДО НУЛАТА ЕНЕРГИЙНА КОНСУМАЦИЯ: ИЗСЛЕДВАНЕ НА СЛУЧАЙ НА ЖИЛИЩЕН БЛОК
Емилия-Черна
Младин, Александру Добровическу, Тудор Присекару
NEARLY-ZERO-ENERGY
BUILDING: STUDY CASE ON A BLOCK OF FLATS
Emilia-Cerna Mladin,
Alexandru Dobrovicescu, Tudor Prisecaru
Abstract:
The study is
focused on a multi-family building block of flats type and
includes an energy analysis on its construction and
installations elements. Results conclude with energy
performance indicators and recommendations for additional
energy efficiency measures. Different packages of measures
were analyzed for economical efficiency and appropriate
conclusions are drawn. It is thus shown how a building can
approach conditions compatible with “nearly zero” energy
consumption from classical sources, with reasonable costs
for owners.
Keywords:
nearly-zero
energy, energy efficiency, energy performance, energy
efficient buildings
ВЛИЯНИЕ НА ПОКРИТИЯТА ВЪРХУ ТОПЛИННИТЕ ХАРАКТЕРИСТИКИ НА СТЪКЛОПАКЕТИ
Нина
Пенкова
INFLUENCE
OF THE COATINGS ON THE THERMAL PERFORMANCE OF INSULATING
GLASS UNITS
Nina Penkova
Abstract: A mathematical model of 3D
conjugated heat transfer at insulating glass units (IGU)
is composed and applied for numerical calculations by
computational fluid dynamic technique with ANSYS.
Temperature field in glass panes and temperature, pressure
and velocity fields in gas space are calculated for
several variants of flat double glazed IGU: uncoated glass
panes; low emissivity coating on inner pane and uncoated
outer glass pane, and solar control coating on outer pane
and uncoated inner glass pane. The numerical calculations
are made for winter and spring conditions in order to
validate the models and to analyze the coatings influence
on thermal behaviour of IGU.
Keywords: IGU, coatings, CFD
calculations, heat transfer, free convection
ИЗЧИСЛЯВАНЕ ХАРАКТЕРИСТИКИТЕ НА ПРОЦЕСА НА
АЕРАЦИЯ НА ВОДИ В НЕСТАЦИОНАРНИ УСЛОВИЯ
Николае
Баран, Александру-Сорин Патулеа, Йонела-Михаела Калусару
COMPUTATION
OF PERFORMANCE AND EFFICIENCY OF THE WATER OXYGENATION
PROCESS IN NON-STATIONARY CONDITIONS
Nicolae Băran, Alexandru
Sorin Pătulea and Ionela Mihaela Căluşaru
Abstract:
The paper presents
a method for computing the performance and efficiency of
the water oxygenation process. The method can be used when
the concentration of dissolved oxygen increases in
function of the duration of the process of introducing in
the water. The theoretical results are verified by
experimental researches.
Keywords:
oxygen dissolved
in water, oxygenation efficiency.