Arhivă — Seria C

1

Characterisation and optimisation of biodiesel’s production from waste cooking oil

Sary Awad, I-A. Basa, M. Paraschiv, S. Kumar, M. Tazerout

We studied the transesterification of two types of waste cooking oil (WCO), with methanol and ethanol using NaOH. Also the physical characteristics of produced biodiesel were studied and compared to the European standard EN 14214. The WCO used in this study was collected from the École des Mines de Nantes university’s …

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2

Modelling of the wind effect on a double-tracking PV platform

Andrei Damian, Andrei-Mugur Georgescu

The objective of the paper is the assessment of the wind load applied to a real photovoltaic (PV) platform installed on a site situated in Brasov, Romania. The platform has a double-tracking axis mechanism, which allows the rotation of the platform depending on the sun position, in order to gather the maximum solar yie…

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3

Two-stage gasification process of solid organic compounds

Cosmin Mãrculescu, Adrian Badea, Tiberiu Apostol

The research focused on two-stage high temperature gasification under steam atmosphere, at atmospheric pressure conducted organic solid compounds for maximum energy potential recovery with respect to product transformation during the process and its influence on final results. The work aimed to establish the dependence…

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4

Pyrolysis parameters influencing the bio-char generation from wooden biomass

Cora Bulmãu (Gheorghe), Cosmin Mãrculescu, Adrian Badea, Tiberiu Apostol

Recently much research has been investigated on identifying suitable biomass species, which can provide high-energy outputs, to replace conventional fossil fuels. This paper reports an approach for increasing the yield of bio-char production from pyrolysis with respect to process conditions. The analyzed material was c…

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5

Energy efficiency and environment

Michel Feidt

In this paper, we intent to review and reconsider the concept of efficiency applied to energy systems and processes. It is shown that due to increasing use of energy, we must refine the criterions that serve as objective functions to characterize and optimize systems and processes. Moreover coupling between energy uses…

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6

The increase of energy efficiency through the conversion of a thermal power plant into a cogeneration plant

Petre Blaga, Horia Necula, Constantin Ionescu

Re-engineering obsolete industrial plants is an increasingly important issue for small and medium enterprises. This paper describes the transformation of a thermal power plant with simultaneous production of low-temperature saturated steam and hot water into a central cogeneration plant, at a company from the drug indu…

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7

Comparative study of heat production by cogeneration or heat pump

André Lallemand, Lingai Luo, Renaud Gicquel

Considering Carnot cycles, it is shown that reducing the power of a thermal power plant to produce cogeneration or using this difference in power to run heat pumps is equivalent in terms of overall performance. Practically, this is however not the same. This conclusion is put in evidence when considering an actual 280 …

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8

Comparative analysis of production and processing of glassware and technical glass

Roxana Patraºcu, George Darie, Eduard Minciuc, Cristian Rãducanu, Adina Stanculea

The article is an integrated approach of energetic efficiency and environmental impact in the field of glass industry. The article is also targeting at improving of energetic and economic efficiency, a reduction of the environment impact and new equipment implementation in the field of glass manufacturing industry in R…

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9

Opportunities to conserve energy right from distribution installations

Gheorghe Cârþinã, Gheorghe Grigoraº, Elena-Crenguþa Bobric

The paper presents a methodology of the evaluation of the energy saving potential in distribution network, by replacement of the old transformers with efficient transformers. The modeling of the transformers load was performed by fuzzy techniques. Finally, a study case for a urban distribution network is presented.

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10

An evolutionary programming application to optimal reactive power dispatch

Florin Ionescu, Constantin Bulac, Ioana Pisicã, Ion Tristiu, Lucian Toma

This paper presents an application of evolutionary programming (EP) to optimal reactive power dispatch (ORDP). The objective of ORDP is to minimize the real power losses and keep the voltages and reactive power generations in their operating limits. In this matter the control variables are generator bus voltages and tr…

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11

Parameters identification of a power plant model for the simulation of islanding transients

Alberto Borghetti, Mauro Bosetti, Carlo Alberto Nucci, Mario Paolone

The paper presents a procedure for parameter identification along with its application to the model of a combined cycle power plant that includes the surrounding electrical network, built for the analysis of islanding maneuvers transients. The paper illustrates both the power system computer model, implemented within t…

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12

Life cycle impact assessment of fossil fuels

Cristian Dincã, Adrian Badea, Tiberiu Apostol

The main objective of this study is to compare the life cycle of fossil fuel (coal, natural gas and oil) in order to assess the overall environmental impact. In this respect it was analyzed the fossil fuels energy production based on the best available energy technologies for each fuel. The methodology used in order to…

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13

New methods for the assessment and the reduction of the co2 emissions in iron and steel processes and thermo-electric power stations, based on an inte

Ion Melinte, Mihaela Bãlãnescu, George Darie, Carmencita Constantin

This paper presents new methods for the assessment and the reduction of the CO2 emissions in iron and steel processes and in thermo-electric power stations, based on a conceptual model for an integrated, technological and energetic system, using the calculus programs and patterns and simulations of the process input pa…

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14

Economical CO2 capture from fossil flue utilization

Elena David, I. ªtefanescu, A. Armeanu

This paper presented an experimental study for CO2 capture from flue gas by pressure swing adsorption process (PSA). Capture of carbon dioxide from a binary mixture (N2/CO2) simulating flue gas was performed by PSA, using selective adsorbents (zeolite-X, carbon molecular sieve, activated carbons). One PSA process consi…

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15

Void reactivity reduction in CANDU reactors using burnable absorbers and advanced fuel designs

Iosif Prodea, Cristina Alice Mãrgeanu, Andrei Rizoiu, Ilie Prisecaru, Nicolae Dãnilã

It is very well known that the CANDU® reactor has positive Coolant Void Reactivity (CVR), which is an important criticisms about CANDU. Recent innovations based on using of a thin absorbent Hafnium shell in the central bundle element were successfully been applied to the Advanced CANDU Reactor (ACR™) project. The paper…

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16

Influence of preheater loss in regeneration efficiency on the secondary circuit

Ilie Prisecaru, Iulian Pavel Niþã, Daniel Dupleac

This paper presents the results of operating analyses in secondary circuit of Cernavoda NPP - Unit 2, in abnormal regimes, due to the failure of a feedwater preheater from the regenerative chain. Based on these analyses, operating solutions are proposed in order to minimize power losses from the normal regime. In this …

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17

Analysis of some critical points that may influence Cernavoda NPP nuclear safety during an earthquake and solutions to increase the safety margin

Viorel ªerban, Ilie Prisecaru

The paper is a general presentation of the main critical points in CERNAVODA NPP- Unit 1 and 2 in respect of seismic behavior, which from the authors’ viewpoint are: \r\n- Fuelling Machine coupled to a fuel channel; -\r\n- The pipe leg of the Emergency Core Cooling System (ECCS) having supports on the inner structure, …

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18

Real efficiency of intelligent switching of high voltage circuit-breakers

Florin Munteanu, Ciprian Nemeº

The concept of intelligent switching means extending the existing controlled switching characteristics to new situations from which the case of faults is the most important. One of the main aspect is related to modern high speed circuit-breakers which are opening before the d.c. component of the short-circuit current i…

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19

Influence factors on the transmitted overvoltages from high voltage to low voltage networks

Marian Costea, Bogdan Nicoarã

In the high and medium voltage networks a large variety of overvoltages can occur. These are produced by lightnings, switching operations or insulation faults. Normally, the protection against overvoltages, based of surge arresters and relay protection of the equipment, act to eliminate or reduce the insulation stress.…

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20

DC arc furnace modelling for power quality analysis

Cristian Lãzãroiu, Dario Zaninelli

The dc arc furnaces are highly disturbing loads for transmission and distribution networks. The present paper deals with the study of the dc arc furnace modeling and analysis of the controller structure for the ac-dc converter, highlighting the advantages obtained regarding power quality improvement. In this study both…

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21

Steady-state stability limit identification for large power systems

Florin Ciauºiu, Mircea Eremia

This paper is treating the problem of steady-state stability reserve identification in a power system when realizing off-line simulations. Even in off-line simulations the stability reserve of a power system is not a straight forward analysis. The difficulties appear when trying to solve the stability reserve aspect fo…

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22

Rough set theory and its applications in electrical power engineering. A survey

Ioana Pisicã, Petru Postolache

Rough Set theory represents a promising technique in imperfect data analysis, which has found interesting extensions and various applications. It can be regarded as complementary to other theories that handle imperfect knowledge, such as Bayesian inference or fuzzy sets. The paper presents some Rough Set Theory concept…

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