WEBREVIEW

Modèle thermochimique bidimensionnel de pyrolyse de la biomasse

Bellettre J. , Castelain C. , Gerun L. , Tazerout M. , Vîjeu R. , Younsi Z. — 2012-01-24T10:13:55Z

La pyrolyse de la biomasse est étudiée. Un modèle thermochimique bidimensionnel basé
sur une méthode nodale a été créé. Il intègre un mécanisme de transfert de chaleur et d'écoulement
diphasiquc. La décomposition du bois s'effectue selon trois réactions concurrentes, produisant coke,
gaz et goudrons. Ces derniers subissent également des réactions secondaires. Des essais sur une
unité de pyrolyse ont permis de caractériser le comportement de la sciure de chêne durant le process.
Les champs de température (...)

- Numéro 03 / Modélisation, Expérimentation, Bois, Pyrolyse, Biomasse

Thermodynamics aspect of high pressure hydrogen production by water electrolysis

Laoun B. — 2012-01-24T10:13:50Z

Hydrogen can be produced from water electrolysis which can operate at atmospheric
pressure or high pressure. Today's industry including vehicle one, devotes efforts to produce high
pressure hydrogen by using pressurized electrolyser. The purpose of this work is to estimate the ideal
electrical energy needed for high pressure hydrogen under high pressure water electrolysis
conditions. Calculations are based on the estimation of the enthalpy and free Gibbs energy of water
electrolysis at (...)

- Numéro 03 / Water Electrolysis, Hydrogen production, High pressure hydrogen, Electrolyser, Enthalpy voltage, Electrolysis voltage, Power

Dielectric properties of flash - evapored CuInSe2 photovoltaic thin films

Abdelali M., Belal T., Linares C., Zair R. — 2012-01-24T10:13:45Z

In this paper, we have analyzed the dielectric functions of CuInSe2 photovoltaic thin
films, ε = ε1 + iε2 .Thus we have obtained the dispersion spectra corresponding to ε1 (λ ) and
ε2 (λ ) from spectrophotometry measurements for different thicknesses of thin films.

- Numéro 03 / CuInSe2 films, Dielectric properties, Critical points, Band structure, Spectroscopic ellipsometry

Asymmetric SPWM used in inverter grid connected

Haddadi M., Hassaine L. , Malek A., Olías E. — 2012-01-24T10:13:40Z

The overall efficiency of grid-connected photovoltaic power generation systems depends
on the efficiency of the DC-into-AC conversion. Therefore, a key consideration in the design and
operation of inverters is how to achieve high efficiency with power output. This paper presents a
concept of an inverter for grid connected photovoltaic arrays which can synchronise a sinusoidal
current output with a voltage grid. Asymmetric PWM inverters can generate power at unity power
factor, this approach, based on the active filter is proposed in this work. This method is used in order
to correct the phase between the output current and the grid voltage and to maximize the system
efficiency in design and control. The functional structure of this system is presented and simulated.
Detailed analysis, Simulations results of output voltage and current waveform demonstrate the
contribution of this approach to determinate the suitable control of the system. A digital design of a
generator SPWM using VHDL is proposed and implemented on an Xilinx FPGA.

Study on solar adsorption refrigeration cycle utilizing activated carbon prepared from olive stones

Addoun A. , Mahmoudi H., Spahis N. — 2012-01-24T10:13:38Z

For countries with a high potential of solar energy, producing cold using solar energy is a promising way to sustainable development since the energy used is free and not harmful for the environment. This work proposes a solar adsorption refrigerator using a compound adsorbent fabricated from activated carbon issued from olive stones. High efficiency activated carbon (AC) with different chemical characteristic was prepared. It was established that activated carbon is obtained from (...)

- Numéro 03 / Absorption, Activated carbon, Compound adsorbent, SEM

Etude des ressources géothermiques du sud algérien

Baddari K., Khellaf A. , Ouali S. — 2012-01-24T10:13:36Z

L'énergie géothermique est l'une des plus importantes sources d'énergies renouvelables
en Algérie. Les utilisations de cette énergie sont multiples. Elles vont des utilisations directes, telles
que la pisciculture, le chauffage des serres et la balnéothérapie aux utilisations industrielles, telles
que la production d'électricité. Si le potentiel des ressources géothermiques du Nord de l'Algérie est
bien déterminé, pour le Sud algérien aucune étude détaillée n'a été encore menée. Le but principal
de la communication est la présentation du potentiel géothermique du Sud algérien à travers une
esquisse du gradient géothermique. Les résultats sont présentés sous forme de cartes et de graphes
de gradient. Ces résultats montrent que le Sud algérien est caractérisé dans son ensemble par un
gradient géothermique moyen 3°C/100m. La partie Est montre une anomalie thermique qui est de 3 à
4°C/100m. Le bassin de Béchar est anormalement chaud avec un gradient dépassant les 7°C/100m.
A travers la carte réalisée, il convient de conclure que les conditions thermiques sont réunies dans le
sud algérien pour avoir un important potentiel géothermique.

Thermal behaviour of a multilayer media in transient regime

Bessaïh R. , Bougriou C., Tamene Y. — 2012-01-24T10:13:32Z

In this paper, we develop a mathematical model, which calculate the temperature and
thermal contact resistance distributions in a multilayer media. This work is composed of two parts.
The first part concerns the analytical solution of the conduction thermal problem for two plates,
which ended in mathematical expressions giving the temperatures and thermal resistance profiles. A
computer code, which calculates the analytical expressions from the values of the temperature at any
time as (...)

- Numéro 03 / Température, Thermal contact resistance, Thermal conduction, Transient state, Multilayer media

Maximum power point tracking using a fuzzy logic control scheme

Aït Cheikh M.S., Larbès C. , Tchoketch Kebir G.F. , Zerguerras A. — 2012-01-24T10:13:28Z

This paper proposes an intelligent control method for the maximum power point tracking
(MPPT) of a photovoltaic system under variable temperature and insolation conditions. This method
uses a fuzzy logic controller applied to a DC-DC converter device. The different steps of the design
of this controller are presented together with its simulation. Results of this simulation are compared
to those obtained by the perturbation and observation controller. They show that the fuzzy logic (...)

- Numéro 03 / Fuzzy logic, Photovoltaic system, MPPT, DC-DC converter

Contribution à l'étude thermique et hydraulique d'un canal plan corrugué

Kadja M., Lanani Benchabi R. — 2012-01-24T10:13:25Z

La préoccupation de fabriquer des échangeurs de chaleur de plus en plus compacts
conduit à rechercher des procédés d'intensification des échangeurs de chaleur. La présente étude est
une contribution à l'étude thermique et dynamique d'un canal plan corrugué simulant un canal
d'échangeur à plaques. Une procédure numérique basée sur la méthode des volumes finis est
appliquée pour la résolution des équations différentielles régissant l'écoulement. Les résultats
obtenus cernent l'influence de certains paramètres (...)

- Numéro 03 / Convection forcée, Volumes finis, Echangeur à plaques, Canal plan corrugué

Numerical modelling of combined heat and mass transfer in a tubular adsorber of a solid adsorption solar refrigerator

Boukheit N. , Chekirou W. , Kerbache T. — 2012-01-24T10:13:20Z

In this paper a theoretical model of the heat and mass processes in a tubular adsorber of
a solid adsorption solar refrigerator is established. The modelling and the analysis of the adsorber is
the key of such studies because of the complex coupled heat and mass transfer phenomena that occur
during the working refrigeration cycle. This model consists of the energy equation in the adsorbent
layers, the energy balance equation of the adsorber wall, and state equation of the bivariant (...)

- Numéro 03 / Adsorption, Solar refrigerator, Heat and mass transfer, Activated carbon AC-35 / methanol, Solar performance coefficient