Browsing by Author "Aissani, S."
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Item Amélioration des performances des turbines à gaz par injection de vapeur d’eau en amont de la chambre de combustion(2008) Bouam, A.; Aissani, S.; Kadi, R.Le rôle des turbines à gaz, dans la production d’électricité, de l’industrie pétrolière et dans les réacteurs à neutrons rapides refroidis en utilisant l’hélium comme fluide caloporteur a pris une attention particulière ces dernières années. A cet effet, différentes méthodes (régénération, refroidissement intermédiaire, préchauffage et injection de la vapeur d’eau) ont été utilisées afin d’améliorer les performances des cycles de turbines à gaz. Dans cette optique, la méthode d’injection de la vapeur d’eau à l’amont de la chambre de combustion d’une turbine à gaz a été proposée, étudiée et comparée avec un cycle simple. L’objectif principal de ce travail consiste à la réalisation d’un programme de calcul de l’influence des conditions ambiantes sur les caractéristiques des différents composants de la turbine à gaz, telles que la compression, la combustion et la détente. Une fois que les paramètres de fonctionnement optimaux sont connus, le recalcul des performances de l’installation a été effectué en injectant des quantités convenables de vapeur d’eau à l’amont de la chambre de combustion. Les résultats obtenus de l’influence des conditions ambiantes sur les performances de la turbine à gaz sans injection de la vapeur d’eau et l’influence des conditions standards sur le début d’injection, selon ceux trouvés dans la littérature simulés par le code de calcul thermodynamique ‘Thermoptim’, sont en bonne concordance avec la variation qualitative de ces conditions, dans le cas d’un fonctionnement normal sans injection de la vapeur. Ces résultats sont représentés sous forme de courbes en deux et à trois dimensions pour une meilleure illustration des phénomènes physiquesItem Assessment of 12 CHF prediction methods, for an axially non-uniform heat flux distribution, with the RELAP5 computer code(2008) Ferrouk, M.; Aissani, S.; D’Auria, F.; DelNevob, A.; Bousbia Salah, A.The present article covers the evaluation of the performance of twelve critical heat flux methods/correlations published in the open literature. The study concerns the imulation of an axially non-uniform heat flux istribution with the RELAP5 computer code in a single boilingwater reactor channel benchmark problem. The nodalization scheme employed for the considered particular geometry, as modelled in RELAP5 code, is described. For this purpose a review of critical heat flux models/correlations applicable to non-uniform axial heat profile is provided. Simulation results using the RELAP5 code and those obtained from our computer program, based on three type redictions methods such as local conditions, F-factor and boiling length average approaches were comparedItem Combustion chamber steam injection for gas turbine performance improvement during high ambient temperature operations(American Society of Mechanical Engineers, 2008) Bouam, A.; Aissani, S.; Kadi, R.The gas turbines are generally used for large scale power generation. The basic gas turbine cycle has low thermal efficiency, which decreases in the hard climatic conditions of operation, so the cycles with thermodynamic improvement is found to be necessary. Among several methods shown their success in increasing the performances, the steam injected gas turbine cycle (STIG) consists of introducing a high amount of steam at various points in the cycle. The main purpose of the present work is to improve the principal characteristics of gas turbine used under hard condition of temperature in Algerian Sahara by injecting steam in the combustion chamber. The suggested method has been studied and compared to a simple cycle. Efficiency, however, is held constant when the ambient temperature increases from ISO conditions to 50°C. Computer program has been developed for various gas turbine processes including the effects of ambient temperature, pressure ratio, injection parameters, standard temperature, and combustion chamber temperature with and without steam injection. Data from the performance testing of an industrial gas turbine, computer model, and theoretical study are used to check the validity of the proposed model. The comparison of the predicted results to the test data is in good agreement. Starting from the advantages, we recommend the use of this method in the industry of hydrocarbons. This study can be contributed for experimental testsItem The Compressibility Effect on the Counting Gas Method Choice(2009) Guemana, M.; Aissani, S.; Bennani, A.The measuring of the quantities of gas is a significant activity of the industry of the transport of gas by drain, as well in the contractual or commercial field as in the technical field where it makes it possible to give essential information for the design of the gas networks. The purpose of this study is essential, after a short recall on the methods of calculation of the factor of compressibility and the flow according to various standards, to give the importance necessary to carry out an adequate choice of the method of calculation of these parametersItem Flow measurement and control in gas pipeline system using intelligent sonic nozzle sensor(2011) Guemana, M.; Aissani, S.; Hafaifa, A.Item Gas turbine performances improvement using steam injection in the combustion chambre under Sahara conditions(2008) Bouam, A.; Aissani, S.; Kadi, R.Gas turbines are generally used for large scale power generation. The basic gas turbine cycle has low thermal efficiency which decreases in the hard climatic conditions of operation, so it is important to look for improved gas turbine based cycles. Among several methods shown their success in increasing the performances, the steam injected gas turbine cycle (STIG) consists to introduce a high amount of steam at various points in the cycle. The objective of the present work is to improve the performances of gas turbine used under Sahara conditions by injecting suitable quantities of steam in the upstream of combustion chamber. The suggested method has been studied and compared with a simple cycle. Efficiency, however, is held constant when the ambient temperature increases from iso conditions to 50C. Computer program has been developed for various gas turbine processes including the effect of ambient temperature. This is achieved by studying the effect of steam injection on the gas turbine performances. Data from the performance testing of an industrial gas turbine, computer model and theoretical study are used to check the validity of the proposed model. The comparison of the prediction results to the test data is in good agreementItem Numerical simulation of the direct contact condensation phenomena for PTS-related in single and combined-effect thermal hydraulic test facilities using TransAT CMFD code(Elseveir, 2015) Kadi, Rabah; Aissani, S.; Bouam, AbdellahItem Use a new calibration method for gas pipelines(2011) Guemana, M.; Aissani, S.; Hafaifa, A.