Dépouillements

FT8-3 advanced low emissions combustor design / Urmila C. Reddy in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 133 N° 11 (Novembre 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 05 p. Titre : FT8-3 advanced low emissions combustor design Type de document : texte imprimé Auteurs : Urmila C. Reddy, Auteur ; Christine E. Blanchard, Auteur ; Barry C. Schlein, Auteur Année de publication : 2012 Article en page(s) : 05 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Combustion  equipment  Gas  turbines  Quenching  (thermal) Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Pratt and Whitney developed a novel water-injected industrial gas turbine combustor liner design that has demonstrated significant reduction in CO emissions when compared with typical film-cooled combustor designs. The CO reduction demonstrated in a prototype test shows that the CO quenching due to cooler film temperatures near the liner wall is a significant source of CO emissions in a conventional water-injected combustor operating on natural gas fuel. This finding paved the way for a combustor design that reduces CO emissions while still maintaining low levels of NOx emissions. This design also has potential for lower NOx since the low CO emissions characteristic enables increased water injection. This paper presents the emissions characteristic measured on prototype hardware and the design of the engine hardware for future validation. Significant reduction in gaseous emissions was demonstrated with the testing of a prototype at the United Technologies Research Center in East Hartford, CT. This reduction in emissions compared with the baseline film-cooled design for a given operating condition has many benefits to the customer, including the reduced need for exhaust catalyst cleanup and extended operating times while still meeting site permits specified in CO tons per year. Other benefits may include the ability to guarantee lower NOx emissions through increased water injection for the current CO emissions output. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...] [article] FT8-3 advanced low emissions combustor design [texte imprimé] / Urmila C. Reddy, Auteur ; Christine E. Blanchard, Auteur ; Barry C. Schlein, Auteur . - 2012 . - 05 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 05 p. Mots-clés : Combustion  equipment  Gas  turbines  Quenching  (thermal) Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Pratt and Whitney developed a novel water-injected industrial gas turbine combustor liner design that has demonstrated significant reduction in CO emissions when compared with typical film-cooled combustor designs. The CO reduction demonstrated in a prototype test shows that the CO quenching due to cooler film temperatures near the liner wall is a significant source of CO emissions in a conventional water-injected combustor operating on natural gas fuel. This finding paved the way for a combustor design that reduces CO emissions while still maintaining low levels of NOx emissions. This design also has potential for lower NOx since the low CO emissions characteristic enables increased water injection. This paper presents the emissions characteristic measured on prototype hardware and the design of the engine hardware for future validation. Significant reduction in gaseous emissions was demonstrated with the testing of a prototype at the United Technologies Research Center in East Hartford, CT. This reduction in emissions compared with the baseline film-cooled design for a given operating condition has many benefits to the customer, including the reduced need for exhaust catalyst cleanup and extended operating times while still meeting site permits specified in CO tons per year. Other benefits may include the ability to guarantee lower NOx emissions through increased water injection for the current CO emissions output. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...]

Emissions from a gas turbine sector rig operated with synthetic aviation and biodiesel fuel / Greg Pucher in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 133 N° 11 (Novembre 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 08 p. Titre : Emissions from a gas turbine sector rig operated with synthetic aviation and biodiesel fuel Type de document : texte imprimé Auteurs : Greg Pucher, Auteur ; William Allan, Auteur ; Marc LaViolette, Auteur Année de publication : 2012 Article en page(s) : 08 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Biofuel  Gas  turbines  Laser  Doppler  anemometry  Nozzles Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Differences in exhaust emissions, smoke production, exhaust pattern factor, deposit buildup, and fuel nozzle spray characteristics for various blends of conventional commercial jet fuel (Jet A-1) with synthetic and biodiesel formulations were investigated. Three synthetic fuel formulations and four fatty acid methyl esters (FAMEs) were evaluated as such. The synthetic fuels were tested in both neat (100%) and 50% by volume blends with Jet A-1, while the FAME fuels were blended in 2% and 20% proportions. The combustion chamber sector rig, which houses a Rolls Royce T-56-A-15 combustion section, was utilized for emissions, deposits, and exhaust pattern factor evaluation. A combustion chamber exhaust plane traversing thermocouple rake was employed to generate two-dimensional temperature maps during operation. Following combustion testing, several combustion system components, including the combustion chamber, fuel nozzle, and igniter plug, were analyzed for relative levels of deposit buildup. A phase Doppler anemometry system was employed to determine differences in droplet size distributions, while an optical spray pattern analyzer was used to compare the spray pattern for the various fuel blends as they emerged from the T-56 nozzle. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...] [article] Emissions from a gas turbine sector rig operated with synthetic aviation and biodiesel fuel [texte imprimé] / Greg Pucher, Auteur ; William Allan, Auteur ; Marc LaViolette, Auteur . - 2012 . - 08 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 08 p. Mots-clés : Biofuel  Gas  turbines  Laser  Doppler  anemometry  Nozzles Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Differences in exhaust emissions, smoke production, exhaust pattern factor, deposit buildup, and fuel nozzle spray characteristics for various blends of conventional commercial jet fuel (Jet A-1) with synthetic and biodiesel formulations were investigated. Three synthetic fuel formulations and four fatty acid methyl esters (FAMEs) were evaluated as such. The synthetic fuels were tested in both neat (100%) and 50% by volume blends with Jet A-1, while the FAME fuels were blended in 2% and 20% proportions. The combustion chamber sector rig, which houses a Rolls Royce T-56-A-15 combustion section, was utilized for emissions, deposits, and exhaust pattern factor evaluation. A combustion chamber exhaust plane traversing thermocouple rake was employed to generate two-dimensional temperature maps during operation. Following combustion testing, several combustion system components, including the combustion chamber, fuel nozzle, and igniter plug, were analyzed for relative levels of deposit buildup. A phase Doppler anemometry system was employed to determine differences in droplet size distributions, while an optical spray pattern analyzer was used to compare the spray pattern for the various fuel blends as they emerged from the T-56 nozzle. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...]

Effects of combustion chamber geometry deviations upon exit temperature profiles for populations with varied service limitations / Clayton Kotzer in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 133 N° 11 (Novembre 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 07 p. Titre : Effects of combustion chamber geometry deviations upon exit temperature profiles for populations with varied service limitations Type de document : texte imprimé Auteurs : Clayton Kotzer, Auteur ; Marc LaViolette, Auteur ; William Allan, Auteur Année de publication : 2012 Article en page(s) : 07 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Combustion  Engines  Gas  turbines  Mach  number  Optical  scanners  Sprays  Temperature  measurement  Test  equipment  Thermocouples Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The purpose of this continuing research was to investigate the effects of combustion chamber geometry on exit temperature fields using a validated ambient pressure test rig. Rig test conditions were set to simulate an engine operating condition of 463 km/h (250 kn) at 7620 m (25,000 ft) by matching Mach number, equivalence ratio, and Sauter mean diameter of the fuel spray. Using a thermocouple rake, high resolution temperature measurements were obtained in the combustion chamber exit plane. Following the previously published procedures, a three-dimensional laser scanning system was used to quantify geometric deviations from two populations of combustion chambers. These populations differed in that one had a significantly higher allowable engine operating temperature for continuous cruise condition. Geometric deviations of both populations were compared with the reference model. The relationship between combustion chamber exit temperature profile and geometric deviation of each population was then compared. The main conclusion of this research was that the temperature profile degradation of both populations due to geometric deviations followed similar trends. These results highlighted that the difference in operating limitations of these populations did not significantly affect component performance. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...] [article] Effects of combustion chamber geometry deviations upon exit temperature profiles for populations with varied service limitations [texte imprimé] / Clayton Kotzer, Auteur ; Marc LaViolette, Auteur ; William Allan, Auteur . - 2012 . - 07 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 07 p. Mots-clés : Combustion  Engines  Gas  turbines  Mach  number  Optical  scanners  Sprays  Temperature  measurement  Test  equipment  Thermocouples Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The purpose of this continuing research was to investigate the effects of combustion chamber geometry on exit temperature fields using a validated ambient pressure test rig. Rig test conditions were set to simulate an engine operating condition of 463 km/h (250 kn) at 7620 m (25,000 ft) by matching Mach number, equivalence ratio, and Sauter mean diameter of the fuel spray. Using a thermocouple rake, high resolution temperature measurements were obtained in the combustion chamber exit plane. Following the previously published procedures, a three-dimensional laser scanning system was used to quantify geometric deviations from two populations of combustion chambers. These populations differed in that one had a significantly higher allowable engine operating temperature for continuous cruise condition. Geometric deviations of both populations were compared with the reference model. The relationship between combustion chamber exit temperature profile and geometric deviation of each population was then compared. The main conclusion of this research was that the temperature profile degradation of both populations due to geometric deviations followed similar trends. These results highlighted that the difference in operating limitations of these populations did not significantly affect component performance. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...]

Approximate nonlinear modeling and feedback linearization control for aeroengines / Hui Zhao in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 133 N° 11 (Novembre 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 10 p. Titre : Approximate nonlinear modeling and feedback linearization control for aeroengines Type de document : texte imprimé Auteurs : Hui Zhao, Auteur ; Jinfu Liu, Auteur ; Daren Yu, Auteur Année de publication : 2012 Article en page(s) : 10 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Aerospace  engines  Aircraft  control  Closed  loop  systems  Feedback  Jet  engines  Linearisation  techniques  Nonlinear  control  systems Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : This paper aims to develop an applicable nonlinear control technique for aeroengines. An approximate nonlinear model is presented and a rational identification procedure is given. Exact input-output feedback linearization can be easily performed on this model. The controller derived can approximately linearize the plant such that the close-loop system exhibits linear input-output dynamics locally. Modeling and controlling are exemplified and validated by a small turbofan engine. Simulation results illustrate that the modeling accuracy is good and linear close-loop system dynamics are achieved. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...] [article] Approximate nonlinear modeling and feedback linearization control for aeroengines [texte imprimé] / Hui Zhao, Auteur ; Jinfu Liu, Auteur ; Daren Yu, Auteur . - 2012 . - 10 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 10 p. Mots-clés : Aerospace  engines  Aircraft  control  Closed  loop  systems  Feedback  Jet  engines  Linearisation  techniques  Nonlinear  control  systems Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : This paper aims to develop an applicable nonlinear control technique for aeroengines. An approximate nonlinear model is presented and a rational identification procedure is given. Exact input-output feedback linearization can be easily performed on this model. The controller derived can approximately linearize the plant such that the close-loop system exhibits linear input-output dynamics locally. Modeling and controlling are exemplified and validated by a small turbofan engine. Simulation results illustrate that the modeling accuracy is good and linear close-loop system dynamics are achieved. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...]

Adaptive PID cascade control for superheated steam temperature based on inverse model / Zhijie Wang in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 133 N° 11 (Novembre 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 06 P. Titre : Adaptive PID cascade control for superheated steam temperature based on inverse model Type de document : texte imprimé Auteurs : Zhijie Wang, Auteur ; Guangjun Wang, Auteur ; Chen, Hong, Auteur Année de publication : 2012 Article en page(s) : 06 P. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Adaptive  control  Boilers  Fuzzy  control  Power  generation  control  Temperature  control  Thermal  power  stations  Three-term  control Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Since the superheated steam temperature system of boiler in thermal power plant is characterized as time varying and nonlinear, it is hard to achieve a satisfactory performance by the conventional proportional-integral-derivative (PID) cascade control scheme. This paper presents a design method of adaptive PID cascade control system for superheated steam temperature based on inverse model: First, the inner loop and the outer process in the cascade control system are equivalent to a generalized plant. A simplified Takagi–Sugeno (STS) fuzzy model is adopted to identify the inverse model of the generalized plant. By choosing the appropriate structure and optimizing with constrains for the parameters of the inverse model, the organic combination of the PID primary controller with the inverse model is realized. To maintain the structure of the existing conventional PID cascade control system in power plant without change, in the control process, the parameters of the primary controller are adjusted on-line according to the identification result of the inverse model of the generalized plant; thus an adaptive PID cascade control system is formed, which matches with the characteristics of the controlled plant. Through the simulation experiments of controlling superheated steam temperature, it is illustrated that the proposed scheme has good adaptability and anti-interference ability. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...] [article] Adaptive PID cascade control for superheated steam temperature based on inverse model [texte imprimé] / Zhijie Wang, Auteur ; Guangjun Wang, Auteur ; Chen, Hong, Auteur . - 2012 . - 06 P. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 06 P. Mots-clés : Adaptive  control  Boilers  Fuzzy  control  Power  generation  control  Temperature  control  Thermal  power  stations  Three-term  control Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Since the superheated steam temperature system of boiler in thermal power plant is characterized as time varying and nonlinear, it is hard to achieve a satisfactory performance by the conventional proportional-integral-derivative (PID) cascade control scheme. This paper presents a design method of adaptive PID cascade control system for superheated steam temperature based on inverse model: First, the inner loop and the outer process in the cascade control system are equivalent to a generalized plant. A simplified Takagi–Sugeno (STS) fuzzy model is adopted to identify the inverse model of the generalized plant. By choosing the appropriate structure and optimizing with constrains for the parameters of the inverse model, the organic combination of the PID primary controller with the inverse model is realized. To maintain the structure of the existing conventional PID cascade control system in power plant without change, in the control process, the parameters of the primary controller are adjusted on-line according to the identification result of the inverse model of the generalized plant; thus an adaptive PID cascade control system is formed, which matches with the characteristics of the controlled plant. Through the simulation experiments of controlling superheated steam temperature, it is illustrated that the proposed scheme has good adaptability and anti-interference ability. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...]

Measurement selections for multicomponent gas path diagnostics using analytical approach and measurement subset concept / Mohd Shahrizal Jasmani in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 133 N° 11 (Novembre 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 10 p. Titre : Measurement selections for multicomponent gas path diagnostics using analytical approach and measurement subset concept Type de document : texte imprimé Auteurs : Mohd Shahrizal Jasmani, Auteur ; Yi-Guang Li, Auteur ; Zaharudin Ariffin, Auteur Année de publication : 2012 Article en page(s) : 10 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Condition  monitoring  Engines  Fault  diagnosis  Gas  turbines Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Gas path analysis (GPA) is a powerful tool to predict gas turbine degradations based on measurement parameters of gas turbine engines. Accordingly, prudent measurement selections are crucial to ensure accurate GPA predictions. This paper is intended to investigate the influence of measurement parameter selection toward the effectiveness of GPA algorithm. An analytical methodology for measurement selection, combined with measurement subset concept, is developed to properly select measurements for multiple component fault diagnosis. The effectiveness of GPA using the measurement sets selected with the introduced measurement selection method are then compared with the results of using standard measurements installed on existing gas turbine engines. A case study applying the new measurement selection method to GPA diagnostic analysis is demonstrated on a three-shaft aeroderivative industrial gas turbine model based on similar unit installed onboard an offshore platform operated by PETRONAS. The engine is modeled and simulated using PYTHIA, a gas turbine performance and diagnostics analysis tool developed by Cranfield University. To validate the findings, nonlinear GPA prediction errors are evaluated in various cases of single and multicomponents faults. As a result, the selected measurements have successfully produced much superior diagnostics accuracies in the fault cases when compared with the standard measurements. These findings proved that proper measurement selection for better GPA diagnostic analysis can be achieved by using the proposed analytical methods. Several engine sensor enhancements are also discussed to accommodate the unique sensor requirements for health diagnostics using GPA. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...] [article] Measurement selections for multicomponent gas path diagnostics using analytical approach and measurement subset concept [texte imprimé] / Mohd Shahrizal Jasmani, Auteur ; Yi-Guang Li, Auteur ; Zaharudin Ariffin, Auteur . - 2012 . - 10 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 10 p. Mots-clés : Condition  monitoring  Engines  Fault  diagnosis  Gas  turbines Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Gas path analysis (GPA) is a powerful tool to predict gas turbine degradations based on measurement parameters of gas turbine engines. Accordingly, prudent measurement selections are crucial to ensure accurate GPA predictions. This paper is intended to investigate the influence of measurement parameter selection toward the effectiveness of GPA algorithm. An analytical methodology for measurement selection, combined with measurement subset concept, is developed to properly select measurements for multiple component fault diagnosis. The effectiveness of GPA using the measurement sets selected with the introduced measurement selection method are then compared with the results of using standard measurements installed on existing gas turbine engines. A case study applying the new measurement selection method to GPA diagnostic analysis is demonstrated on a three-shaft aeroderivative industrial gas turbine model based on similar unit installed onboard an offshore platform operated by PETRONAS. The engine is modeled and simulated using PYTHIA, a gas turbine performance and diagnostics analysis tool developed by Cranfield University. To validate the findings, nonlinear GPA prediction errors are evaluated in various cases of single and multicomponents faults. As a result, the selected measurements have successfully produced much superior diagnostics accuracies in the fault cases when compared with the standard measurements. These findings proved that proper measurement selection for better GPA diagnostic analysis can be achieved by using the proposed analytical methods. Several engine sensor enhancements are also discussed to accommodate the unique sensor requirements for health diagnostics using GPA. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...]

The brayton cycle using real air and polytropic component efficiencies / W. H. Heiser in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 133 N° 11 (Novembre 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 09 p. Titre : The brayton cycle using real air and polytropic component efficiencies Type de document : texte imprimé Auteurs : W. H. Heiser, Auteur ; T. Huxley, Auteur ; J. W. Bucey, Auteur Année de publication : 2012 Article en page(s) : 09 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Air  Brayton  cycle  Propulsion  Specific  heat  Thermal  expansion  Thermodynamics Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : This paper presents the results of a fundamental, comprehensive, and rigorous analytical and computational examination of the performance of the Brayton propulsion and power cycle employing real air as the working fluid. This approach capitalizes on the benefits inherent in closed cycle thermodynamic reasoning and the behavior of the thermally perfect gas to facilitate analysis. The analysis uses a high fidelity correlation to represent the specific heat at constant pressure of air as a function of temperature and the polytropic efficiency to evaluate the overall efficiency of the adiabatic compression and expansion processes. The analytical results are algebraic, transparent, and easily manipulated, and the computational results present a useful guidance for designers and users. The operating range of design parameters considered covers any current and foreseeable application. The results include some important comparisons with more simplified conventional analyses. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...] [article] The brayton cycle using real air and polytropic component efficiencies [texte imprimé] / W. H. Heiser, Auteur ; T. Huxley, Auteur ; J. W. Bucey, Auteur . - 2012 . - 09 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 09 p. Mots-clés : Air  Brayton  cycle  Propulsion  Specific  heat  Thermal  expansion  Thermodynamics Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : This paper presents the results of a fundamental, comprehensive, and rigorous analytical and computational examination of the performance of the Brayton propulsion and power cycle employing real air as the working fluid. This approach capitalizes on the benefits inherent in closed cycle thermodynamic reasoning and the behavior of the thermally perfect gas to facilitate analysis. The analysis uses a high fidelity correlation to represent the specific heat at constant pressure of air as a function of temperature and the polytropic efficiency to evaluate the overall efficiency of the adiabatic compression and expansion processes. The analytical results are algebraic, transparent, and easily manipulated, and the computational results present a useful guidance for designers and users. The operating range of design parameters considered covers any current and foreseeable application. The results include some important comparisons with more simplified conventional analyses. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...]

Optimum sizing of the prime mover in a medium scale gas turbine CHP system / Mehdi Aghaei Meybodi in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 133 N° 11 (Novembre 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 07 p. Titre : Optimum sizing of the prime mover in a medium scale gas turbine CHP system Type de document : texte imprimé Auteurs : Mehdi Aghaei Meybodi, Auteur ; Masud Behnia, Auteur Année de publication : 2012 Article en page(s) : 07 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Cogeneration  Environmental  economics  Gas  turbines  Power  generation  economics  Power  generation  planning  Power  grids  Sensitivity  analysis Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Optimum selection of prime movers in combined heat and power (CHP) systems is of crucial importance due to the fact that inappropriate choices reduce the benefits of CHP systems considerably. In the selection procedure, the performance characteristics of prime movers as well as economic parameters should be taken into account. In this paper, a thermo-economic method for selecting the optimum nominal power and planning the operational strategy of gas turbine as the prime mover of a medium scale (500–5000 kW) CHP system is presented. Appropriate relations for estimating thermodynamic and economic parameters of the system in the context of net annual cost criterion are introduced. Three modes of operation have been considered, namely, two-way connection (TWC) mode, one-way connection (OWC) mode, and heat demand following (HDF) mode. In TWC mode, buying electricity from the grid and selling the excess electricity to the grid are allowed. OWC mode is a situation in which it is only possible to buy electricity from the grid. In HDF mode, buying electricity from the grid and selling electricity to the grid are allowed. HDF mode of operation is considered to have the minimum waste of energy due to the fact that prime movers work in a condition at which the excess produced heat is minimal. As a way of dealing with the environmental concerns, the impact of carbon tax has also been studied. The proposed method has been used for a case study. It was observed that the optimum nominal powers in TWC mode, OWC mode, and HDF mode are 3.5 MW, 3.4 MW, and 0.8 MW, respectively. Furthermore, in order to determine the sensitivity of results to parameters such as cost of electricity, cost of fuel, and carbon tax, a comprehensive sensitivity analysis was conducted. It is noted that the proposed method may be used for other types of prime movers (such as internal combustion engines) as well as various sizes of combined heat and power systems. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...] [article] Optimum sizing of the prime mover in a medium scale gas turbine CHP system [texte imprimé] / Mehdi Aghaei Meybodi, Auteur ; Masud Behnia, Auteur . - 2012 . - 07 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 07 p. Mots-clés : Cogeneration  Environmental  economics  Gas  turbines  Power  generation  economics  Power  generation  planning  Power  grids  Sensitivity  analysis Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Optimum selection of prime movers in combined heat and power (CHP) systems is of crucial importance due to the fact that inappropriate choices reduce the benefits of CHP systems considerably. In the selection procedure, the performance characteristics of prime movers as well as economic parameters should be taken into account. In this paper, a thermo-economic method for selecting the optimum nominal power and planning the operational strategy of gas turbine as the prime mover of a medium scale (500–5000 kW) CHP system is presented. Appropriate relations for estimating thermodynamic and economic parameters of the system in the context of net annual cost criterion are introduced. Three modes of operation have been considered, namely, two-way connection (TWC) mode, one-way connection (OWC) mode, and heat demand following (HDF) mode. In TWC mode, buying electricity from the grid and selling the excess electricity to the grid are allowed. OWC mode is a situation in which it is only possible to buy electricity from the grid. In HDF mode, buying electricity from the grid and selling electricity to the grid are allowed. HDF mode of operation is considered to have the minimum waste of energy due to the fact that prime movers work in a condition at which the excess produced heat is minimal. As a way of dealing with the environmental concerns, the impact of carbon tax has also been studied. The proposed method has been used for a case study. It was observed that the optimum nominal powers in TWC mode, OWC mode, and HDF mode are 3.5 MW, 3.4 MW, and 0.8 MW, respectively. Furthermore, in order to determine the sensitivity of results to parameters such as cost of electricity, cost of fuel, and carbon tax, a comprehensive sensitivity analysis was conducted. It is noted that the proposed method may be used for other types of prime movers (such as internal combustion engines) as well as various sizes of combined heat and power systems. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...]

Oil mist eliminator vessel modifications for GE 7EA gas turbine / Steve Ingistov in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 133 N° 11 (Novembre 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 06 p. Titre : Oil mist eliminator vessel modifications for GE 7EA gas turbine Type de document : texte imprimé Auteurs : Steve Ingistov, Auteur ; Roger Cusack, Auteur ; Rakesh Bhargava, Auteur Année de publication : 2012 Article en page(s) : 06 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Cogeneration  Gas  turbines  Lubricating  oils Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : With any rotating machinery as lube oil leaves bearings, a certain amount of lube oil is aerated, resulting in the formation of a mist of very small size (less than 1 µm diameter) particles. If oil mist elimination system is not sized and designed properly, it could cause various issues such as increased operation and maintenance cost, re-entry of oily air into adjacent gas turbine units, fouling of surrounding atmosphere, and creation of oil slick on concrete floors, besides impacting environmental requirements and safety hazards. This paper presents a case study involving GE 7EA gas turbines operating at the Watson Cogeneration Plant and discusses issues with the existing oil mist elimination system and steps taken for a successful replacement of the original equipment manufacturer (OEM) supplied mist elimination system with non-OEM designed and fabricated mist elimination system. The replaced system demonstrated significantly higher life expectancy than it was designed for. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...] [article] Oil mist eliminator vessel modifications for GE 7EA gas turbine [texte imprimé] / Steve Ingistov, Auteur ; Roger Cusack, Auteur ; Rakesh Bhargava, Auteur . - 2012 . - 06 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 06 p. Mots-clés : Cogeneration  Gas  turbines  Lubricating  oils Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : With any rotating machinery as lube oil leaves bearings, a certain amount of lube oil is aerated, resulting in the formation of a mist of very small size (less than 1 µm diameter) particles. If oil mist elimination system is not sized and designed properly, it could cause various issues such as increased operation and maintenance cost, re-entry of oily air into adjacent gas turbine units, fouling of surrounding atmosphere, and creation of oil slick on concrete floors, besides impacting environmental requirements and safety hazards. This paper presents a case study involving GE 7EA gas turbines operating at the Watson Cogeneration Plant and discusses issues with the existing oil mist elimination system and steps taken for a successful replacement of the original equipment manufacturer (OEM) supplied mist elimination system with non-OEM designed and fabricated mist elimination system. The replaced system demonstrated significantly higher life expectancy than it was designed for. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...]

Identification of rotordynamic force coefficients of a metal mesh foil bearing using impact load excitations / Luis San Andrés in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 133 N° 11 (Novembre 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 09 p. Titre : Identification of rotordynamic force coefficients of a metal mesh foil bearing using impact load excitations Type de document : texte imprimé Auteurs : Luis San Andrés, Auteur ; Thomas Abraham Chirathadam, Auteur Année de publication : 2012 Article en page(s) : 09 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Damping  Elastic  constants  Impact  (mechanical)  Machine  bearings  Rotors  Stress  analysis  Turbomachinery Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Metal mesh foil bearings (MMFBs) are inexpensive compliant gas bearing type that aim to enable high speed, high temperature operation of small turbomachinery. A MMFB with an inner diameter of 28.00 mm and length of 28.05 mm is constructed with low cost and common materials. The bearing incorporates a copper mesh ring, 20% in compactness, and offering large material damping beneath a 0.127 mm thick preformed top foil. Prior experimentations (published papers) provide the bearing structure force coefficients and the break away torque for bearing lift off. Presently, the MMFB replaces a compressor in a small turbocharger driven test rig. Impact load tests aid to identify the direct and cross-coupled rotor dynamic force coefficients of the floating MMFB while operating at a speed of 50 krpm. Tests conducted with and without shaft rotation show the MMFB direct stiffness is less than its structural (static) stiffness, ~25% lower at an excitation frequency of 200 Hz. The thin air film acting in series with the metal mesh support and separating the rotating shaft and the bearing inner surface while airborne reduces the bearing stiffness. The equivalent viscous damping is nearly identical with and without shaft rotation. The identified loss factor, best representing the hysteretic type damping from the metal mesh, is high at ~0.50 in the frequency range 0–200 Hz. This magnitude reveals large mechanical energy dissipation ability from the MMFB. The measurements also show appreciable cross directional motions from the unidirectional impact loads, thus generating appreciable cross-coupled force coefficients. Rotor speed coast down measurements reveal pronounced subsynchronous whirl motion amplitudes locked at distinct frequencies. The MMFB stiffness hardening nonlinearity produces the rich frequency forced response. The synchronous as well as subsynchronous motions peak while the shaft traverses its critical speeds. The measurements establish reliable operation of the test MMFB while airborne. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...] [article] Identification of rotordynamic force coefficients of a metal mesh foil bearing using impact load excitations [texte imprimé] / Luis San Andrés, Auteur ; Thomas Abraham Chirathadam, Auteur . - 2012 . - 09 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 09 p. Mots-clés : Damping  Elastic  constants  Impact  (mechanical)  Machine  bearings  Rotors  Stress  analysis  Turbomachinery Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Metal mesh foil bearings (MMFBs) are inexpensive compliant gas bearing type that aim to enable high speed, high temperature operation of small turbomachinery. A MMFB with an inner diameter of 28.00 mm and length of 28.05 mm is constructed with low cost and common materials. The bearing incorporates a copper mesh ring, 20% in compactness, and offering large material damping beneath a 0.127 mm thick preformed top foil. Prior experimentations (published papers) provide the bearing structure force coefficients and the break away torque for bearing lift off. Presently, the MMFB replaces a compressor in a small turbocharger driven test rig. Impact load tests aid to identify the direct and cross-coupled rotor dynamic force coefficients of the floating MMFB while operating at a speed of 50 krpm. Tests conducted with and without shaft rotation show the MMFB direct stiffness is less than its structural (static) stiffness, ~25% lower at an excitation frequency of 200 Hz. The thin air film acting in series with the metal mesh support and separating the rotating shaft and the bearing inner surface while airborne reduces the bearing stiffness. The equivalent viscous damping is nearly identical with and without shaft rotation. The identified loss factor, best representing the hysteretic type damping from the metal mesh, is high at ~0.50 in the frequency range 0–200 Hz. This magnitude reveals large mechanical energy dissipation ability from the MMFB. The measurements also show appreciable cross directional motions from the unidirectional impact loads, thus generating appreciable cross-coupled force coefficients. Rotor speed coast down measurements reveal pronounced subsynchronous whirl motion amplitudes locked at distinct frequencies. The MMFB stiffness hardening nonlinearity produces the rich frequency forced response. The synchronous as well as subsynchronous motions peak while the shaft traverses its critical speeds. The measurements establish reliable operation of the test MMFB while airborne. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...]

The effect of iso-octane addition on combustion and emission characteristics of a HCCI engine fueled with n-heptane / Cosmin E. Dumitrescu in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 133 N° 11 (Novembre 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 07 p. Titre : The effect of iso-octane addition on combustion and emission characteristics of a HCCI engine fueled with n-heptane Type de document : texte imprimé Auteurs : Cosmin E. Dumitrescu, Auteur ; Hongsheng Guo, Auteur ; Vahid Hosseini, Auteur Année de publication : 2012 Article en page(s) : 07 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Air  pollution  Combustion  Fuel  Ignition  Internal  combustion  engines Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : This paper investigates the effects of iso-octane addition on the combustion and emission characteristics of a single-cylinder, variable compression ratio, homogeneous charge compression ignition (HCCI) engine fueled with n-heptane. The engine was operated with four fuel blends containing up to 50% iso-octane by liquid volume at 900 rpm, 50:1 air-to-fuel ratio, no exhaust gas recirculation, and an intake mixture temperature of 30°C. A detailed analysis of the regulated and unregulated emissions was performed including validation of the experimental results using a multizone model with detailed fuel chemistry. The results show that iso-octane addition reduced HCCI combustion efficiency and retarded the combustion phasing. The range of engine compression ratios where satisfactory HCCI combustion occurred was found to narrow with increasing iso-octane percentage in the fuel. NOx emissions increased with iso-octane addition at advanced combustion phasing, but the influence of iso-octane addition was negligible once CA50 (crank angle position at which 50% heat is released) was close to or after top dead center. The total unburned hydrocarbons (THC) in the exhaust consisted primarily of alkanes, alkenes, and oxygenated hydrocarbons. The percentage of alkanes, the dominant class of THC emissions, was found to be relatively constant. The alkanes were composed primarily of unburned fuel compounds, and iso-octane addition monotonically increased and decreased the iso-octane and n-heptane percentages in the THC emissions, respectively. The percentage of alkenes in the THC was not significantly affected by iso-octane addition. Iso-octane addition increased the percentage of oxygenated hydrocarbons. Small quantities of cycloalkanes and aromatics were detected when the iso-octane percentage was increased beyond 30%. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...] [article] The effect of iso-octane addition on combustion and emission characteristics of a HCCI engine fueled with n-heptane [texte imprimé] / Cosmin E. Dumitrescu, Auteur ; Hongsheng Guo, Auteur ; Vahid Hosseini, Auteur . - 2012 . - 07 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 07 p. Mots-clés : Air  pollution  Combustion  Fuel  Ignition  Internal  combustion  engines Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : This paper investigates the effects of iso-octane addition on the combustion and emission characteristics of a single-cylinder, variable compression ratio, homogeneous charge compression ignition (HCCI) engine fueled with n-heptane. The engine was operated with four fuel blends containing up to 50% iso-octane by liquid volume at 900 rpm, 50:1 air-to-fuel ratio, no exhaust gas recirculation, and an intake mixture temperature of 30°C. A detailed analysis of the regulated and unregulated emissions was performed including validation of the experimental results using a multizone model with detailed fuel chemistry. The results show that iso-octane addition reduced HCCI combustion efficiency and retarded the combustion phasing. The range of engine compression ratios where satisfactory HCCI combustion occurred was found to narrow with increasing iso-octane percentage in the fuel. NOx emissions increased with iso-octane addition at advanced combustion phasing, but the influence of iso-octane addition was negligible once CA50 (crank angle position at which 50% heat is released) was close to or after top dead center. The total unburned hydrocarbons (THC) in the exhaust consisted primarily of alkanes, alkenes, and oxygenated hydrocarbons. The percentage of alkanes, the dominant class of THC emissions, was found to be relatively constant. The alkanes were composed primarily of unburned fuel compounds, and iso-octane addition monotonically increased and decreased the iso-octane and n-heptane percentages in the THC emissions, respectively. The percentage of alkenes in the THC was not significantly affected by iso-octane addition. Iso-octane addition increased the percentage of oxygenated hydrocarbons. Small quantities of cycloalkanes and aromatics were detected when the iso-octane percentage was increased beyond 30%. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...]

Impact of orifice angle configurations on the droplet atomization enhancement of diesel fuel in a group-hole nozzle / Hyun Kyu Suh in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 133 N° 11 (Novembre 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 07 p. Titre : Impact of orifice angle configurations on the droplet atomization enhancement of diesel fuel in a group-hole nozzle Type de document : texte imprimé Auteurs : Hyun Kyu Suh, Auteur ; Chang Sik Lee, Auteur Année de publication : 2012 Article en page(s) : 07 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Diesel  engines  Dissociation  Drops  Nozzles  Orifices  (mechanical)  Petroleum  Sprays Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : This paper presents the effect of orifice configuration on the droplet atomization characteristics of diesel fuel injected through different types of group-hole nozzle angles, which are converged (theta=−3 deg), parallel (theta=0 deg), and diverged (theta=+3 deg) orifices in atmospheric pressure and room temperature condition (0.1 MPa, 293 K). It was revealed that the parallel hole nozzle has the largest Sauter mean diameter (SMD) value and both sprays from diverged and converged hole nozzles show better atomization. A comparison of spray tip penetration illustrates that as the orifice angle is converged, spray tip penetration becomes longer, and it must be the reason for the fast spray velocity. These results can confirm the relationship among time, distance, and velocity. Therefore, it can be concluded that the droplet atomization enhancement can be expected in the converged nozzle spray rather than in the parallel and diverged nozzle sprays based on the results of smaller SMD, faster velocity, better air utilization, and higher percentage of small size of droplets in the measuring area. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...] [article] Impact of orifice angle configurations on the droplet atomization enhancement of diesel fuel in a group-hole nozzle [texte imprimé] / Hyun Kyu Suh, Auteur ; Chang Sik Lee, Auteur . - 2012 . - 07 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 07 p. Mots-clés : Diesel  engines  Dissociation  Drops  Nozzles  Orifices  (mechanical)  Petroleum  Sprays Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : This paper presents the effect of orifice configuration on the droplet atomization characteristics of diesel fuel injected through different types of group-hole nozzle angles, which are converged (theta=−3 deg), parallel (theta=0 deg), and diverged (theta=+3 deg) orifices in atmospheric pressure and room temperature condition (0.1 MPa, 293 K). It was revealed that the parallel hole nozzle has the largest Sauter mean diameter (SMD) value and both sprays from diverged and converged hole nozzles show better atomization. A comparison of spray tip penetration illustrates that as the orifice angle is converged, spray tip penetration becomes longer, and it must be the reason for the fast spray velocity. These results can confirm the relationship among time, distance, and velocity. Therefore, it can be concluded that the droplet atomization enhancement can be expected in the converged nozzle spray rather than in the parallel and diverged nozzle sprays based on the results of smaller SMD, faster velocity, better air utilization, and higher percentage of small size of droplets in the measuring area. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...]

Exergoeconomic analysis of an advanced zero emission plant / Fontina Petrakopoulou in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 133 N° 11 (Novembre 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 12 p. Titre : Exergoeconomic analysis of an advanced zero emission plant Type de document : texte imprimé Auteurs : Fontina Petrakopoulou, Auteur ; George Tsatsaronis, Auteur ; Tatiana Morosuk, Auteur Année de publication : 2012 Article en page(s) : 12 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Air  pollution  control  Climate  mitigation  Combined  cycle  power  stations  Combustion  Exergy Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : In this paper, an advanced zero emission plant using oxy-fuel combustion is presented and compared with a reference plant (a) without CO2 capture and (b) with CO2 capture via chemical absorption. A variation of the oxy-fuel plant with a lower CO2 capture percentage (85%) is also presented, in order to (1) evaluate the influence of CO2 capture on the overall performance and cost of the plant and (2) enable comparison at the plant-level with the conventional method for CO2 capture: chemical absorption with monoethanolamine. Selected results of an advanced exergetic analysis are also briefly presented to provide an overview of further development of evaluation methodologies, as well as deeper insight into power plant design. When compared with the reference case, the oxy-fuel plants with 100% and 85% CO2 captures suffer only a relatively small decrease in efficiency, essentially due to their more efficient combustion processes that make up for the additional thermodynamic inefficiencies and energy requirements. Investment cost estimates show that the membrane used for the oxygen production in the oxy-fuel plants is the most expensive component. If less expensive materials can be used for the mixed conducting membrane reactor used in the plants, the overall plant expenditures can be significantly reduced. Using the results of the exergoeconomic analysis, the components with the higher influence on the overall plant are revealed and possible changes to improve the plants are suggested. Design modifications that can lead to further decreases in the costs of electricity and CO2 capture, are discussed in detail. Overall, the calculated cost of electricity and the cost of avoided CO2 from the oxy-fuel plants are calculated to be competitive with those of chemical absorption. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...] [article] Exergoeconomic analysis of an advanced zero emission plant [texte imprimé] / Fontina Petrakopoulou, Auteur ; George Tsatsaronis, Auteur ; Tatiana Morosuk, Auteur . - 2012 . - 12 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 12 p. Mots-clés : Air  pollution  control  Climate  mitigation  Combined  cycle  power  stations  Combustion  Exergy Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : In this paper, an advanced zero emission plant using oxy-fuel combustion is presented and compared with a reference plant (a) without CO2 capture and (b) with CO2 capture via chemical absorption. A variation of the oxy-fuel plant with a lower CO2 capture percentage (85%) is also presented, in order to (1) evaluate the influence of CO2 capture on the overall performance and cost of the plant and (2) enable comparison at the plant-level with the conventional method for CO2 capture: chemical absorption with monoethanolamine. Selected results of an advanced exergetic analysis are also briefly presented to provide an overview of further development of evaluation methodologies, as well as deeper insight into power plant design. When compared with the reference case, the oxy-fuel plants with 100% and 85% CO2 captures suffer only a relatively small decrease in efficiency, essentially due to their more efficient combustion processes that make up for the additional thermodynamic inefficiencies and energy requirements. Investment cost estimates show that the membrane used for the oxygen production in the oxy-fuel plants is the most expensive component. If less expensive materials can be used for the mixed conducting membrane reactor used in the plants, the overall plant expenditures can be significantly reduced. Using the results of the exergoeconomic analysis, the components with the higher influence on the overall plant are revealed and possible changes to improve the plants are suggested. Design modifications that can lead to further decreases in the costs of electricity and CO2 capture, are discussed in detail. Overall, the calculated cost of electricity and the cost of avoided CO2 from the oxy-fuel plants are calculated to be competitive with those of chemical absorption. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...]

A new model for the analysis and simulation of steam turbines at partial and full load / Mario Álvarez Fernández in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 133 N° 11 (Novembre 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 10 p. Titre : A new model for the analysis and simulation of steam turbines at partial and full load Type de document : texte imprimé Auteurs : Mario Álvarez Fernández, Auteur ; Cristina Alonso-Tristán, Auteur Année de publication : 2012 Article en page(s) : 10 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Steam  turbines Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : A model is described that studies the behavior of a steam turbine on the basis of the law of conservation of energy even under wet-steam conditions at particular points in time. Initially, the hypothesis that steam expansion follows a polytropic function will be demonstrated, and a procedure for the calculation of the polytropic exponent will be introduced. Then, the real thermal power given by the steam turbine will be calculated when the steam at the discharge section is wet steam. This calculation has not been analytically developed until now. Two factors will likewise be introduced: a flow factor (used in order to simulate the discharge pressure) and a loss factor (used in order to simulate the discharge enthalpy). With these factors, the steam at the outlet section of a steam turbine will be fully simulated. Furthermore, the loss factor can be used to evaluate the efficiency of the steam turbine. All the equations are validated at both partial and full loads and will be implemented in a real case study: the High Pressure Turbine of the Santa María de Garoña Nuclear Power Plant, which operates at all times under wet-steam conditions, making it particularly relevant for this study. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...] [article] A new model for the analysis and simulation of steam turbines at partial and full load [texte imprimé] / Mario Álvarez Fernández, Auteur ; Cristina Alonso-Tristán, Auteur . - 2012 . - 10 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 10 p. Mots-clés : Steam  turbines Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : A model is described that studies the behavior of a steam turbine on the basis of the law of conservation of energy even under wet-steam conditions at particular points in time. Initially, the hypothesis that steam expansion follows a polytropic function will be demonstrated, and a procedure for the calculation of the polytropic exponent will be introduced. Then, the real thermal power given by the steam turbine will be calculated when the steam at the discharge section is wet steam. This calculation has not been analytically developed until now. Two factors will likewise be introduced: a flow factor (used in order to simulate the discharge pressure) and a loss factor (used in order to simulate the discharge enthalpy). With these factors, the steam at the outlet section of a steam turbine will be fully simulated. Furthermore, the loss factor can be used to evaluate the efficiency of the steam turbine. All the equations are validated at both partial and full loads and will be implemented in a real case study: the High Pressure Turbine of the Santa María de Garoña Nuclear Power Plant, which operates at all times under wet-steam conditions, making it particularly relevant for this study. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...]

Conceptual structure design of high temperature isolation valve for high temperature gas cooled reactor / Shoji Takada in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 133 N° 11 (Novembre 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 03 p. Titre : Conceptual structure design of high temperature isolation valve for high temperature gas cooled reactor Type de document : texte imprimé Auteurs : Shoji Takada, Auteur ; Kenji Abe, Auteur ; Yoshiyuki Inagaki, Auteur Année de publication : 2012 Article en page(s) : 03 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Alloys  Creep  Fatigue  Fission  reactor  safety  Gas  cooled  reactors  Hydrogen  production  Thermal  insulation  Thermal  stresses  Valves Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The high temperature isolation valve (HTIV) is a key component to assure the safety of a high temperature gas cooled reactor connected with a hydrogen production system for protections of radioactive material release from the reactor to the hydrogen production system as well as of combustible gas ingress to the reactor at the accident of fracture of an intermediate heat exchanger and the chemical reactor. However, the HTIV has not been made for practical use in the helium condition over 900°C yet. The conceptual structure design of an angle type HTIV was carried out. A seat made of Hasteloy-XR is welded inside a valve box. Internal thermal insulation is employed around the seat and a liner because the high temperature helium gas flows inside the valve. The inner diameter of the top of seat was set 445 mm based on fabrication experiences of valve makers. A draft overall structure was proposed based on the diameter of the seat. The numerical analysis was carried out to estimate the temperature distribution and stress of metallic components by using a three-dimensional finite element method code. Numerical results showed that the temperature of the seat was simply decreased from the top around 900°C to the root, and the thermal stress locally increased at the root of the seat, which was connected with the valve box. The stress was lowered below the allowable limit 120 MPa by decreasing the thickness of the connecting part and increasing the temperature of the valve box to around 350°C. The stress also increased at the top of the seat. Creep analysis revealed that the intactness of the HTIV is kept after the assumed operation cycles of the plant life as well as at the depressurization accident. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...] [article] Conceptual structure design of high temperature isolation valve for high temperature gas cooled reactor [texte imprimé] / Shoji Takada, Auteur ; Kenji Abe, Auteur ; Yoshiyuki Inagaki, Auteur . - 2012 . - 03 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 03 p. Mots-clés : Alloys  Creep  Fatigue  Fission  reactor  safety  Gas  cooled  reactors  Hydrogen  production  Thermal  insulation  Thermal  stresses  Valves Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The high temperature isolation valve (HTIV) is a key component to assure the safety of a high temperature gas cooled reactor connected with a hydrogen production system for protections of radioactive material release from the reactor to the hydrogen production system as well as of combustible gas ingress to the reactor at the accident of fracture of an intermediate heat exchanger and the chemical reactor. However, the HTIV has not been made for practical use in the helium condition over 900°C yet. The conceptual structure design of an angle type HTIV was carried out. A seat made of Hasteloy-XR is welded inside a valve box. Internal thermal insulation is employed around the seat and a liner because the high temperature helium gas flows inside the valve. The inner diameter of the top of seat was set 445 mm based on fabrication experiences of valve makers. A draft overall structure was proposed based on the diameter of the seat. The numerical analysis was carried out to estimate the temperature distribution and stress of metallic components by using a three-dimensional finite element method code. Numerical results showed that the temperature of the seat was simply decreased from the top around 900°C to the root, and the thermal stress locally increased at the root of the seat, which was connected with the valve box. The stress was lowered below the allowable limit 120 MPa by decreasing the thickness of the connecting part and increasing the temperature of the valve box to around 350°C. The stress also increased at the top of the seat. Creep analysis revealed that the intactness of the HTIV is kept after the assumed operation cycles of the plant life as well as at the depressurization accident. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...]

Development of a spark discharge PM sensor for measurement of engine-out soot emissions / David P. Gardiner in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 133 N° 11 (Novembre 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 04 p. Titre : Development of a spark discharge PM sensor for measurement of engine-out soot emissions Type de document : texte imprimé Auteurs : David P. Gardiner, Auteur ; Greg R. Pucher, Auteur ; William D. Allan, Auteur Année de publication : 2012 Article en page(s) : 04 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Diesel  engines  Smoke  detectors Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : There is interest in measuring the engine-out particulate emissions from diesel engines in real time in order to optimize the engine control strategies such as exhaust gas recirculation (EGR) and monitor the loading of the particulate filter. This paper presents experimental results obtained using a measurement technique that produced a signal proportional to the peak voltage of a spark discharge that was exposed to the exhaust gas. The sensor was tested on a turbocharged diesel engine with exhaust soot levels from <0.1 FSN to >3.5 FSN, and compared with reference measurements of filter smoke number (FSN) from an AVL 415S smokemeter. The sensor signal showed a high correlation with the reference FSN measurements. Conversion of the FSN values to mass concentration values (using published techniques for the reference instrument) indicated that the output of the spark discharge soot sensor was nearly linear with mass concentration over a substantial portion of the measuring range. The sensor showed a response time of less than 2 s to step changes in FSN levels. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...] [article] Development of a spark discharge PM sensor for measurement of engine-out soot emissions [texte imprimé] / David P. Gardiner, Auteur ; Greg R. Pucher, Auteur ; William D. Allan, Auteur . - 2012 . - 04 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 04 p. Mots-clés : Diesel  engines  Smoke  detectors Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : There is interest in measuring the engine-out particulate emissions from diesel engines in real time in order to optimize the engine control strategies such as exhaust gas recirculation (EGR) and monitor the loading of the particulate filter. This paper presents experimental results obtained using a measurement technique that produced a signal proportional to the peak voltage of a spark discharge that was exposed to the exhaust gas. The sensor was tested on a turbocharged diesel engine with exhaust soot levels from <0.1 FSN to >3.5 FSN, and compared with reference measurements of filter smoke number (FSN) from an AVL 415S smokemeter. The sensor signal showed a high correlation with the reference FSN measurements. Conversion of the FSN values to mass concentration values (using published techniques for the reference instrument) indicated that the output of the spark discharge soot sensor was nearly linear with mass concentration over a substantial portion of the measuring range. The sensor showed a response time of less than 2 s to step changes in FSN levels. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...]

Effects of pressure ratio and rotational speed on leakage flow and cavity pressure in the staggered labyrinth seal / Zhigang Li in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 133 N° 11 (Novembre 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 06 p. Titre : Effects of pressure ratio and rotational speed on leakage flow and cavity pressure in the staggered labyrinth seal Type de document : texte imprimé Auteurs : Zhigang Li, Auteur ; Jun Li, Auteur ; Xin Yan, Auteur Année de publication : 2012 Article en page(s) : 06 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Flow  simulation  Flowmeters  Navier-Stokes  equations  Numerical  analysis  Pressure  measurement  Rotational  flow  Seals  (stoppers)  Turbines  Turbulence Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Effects of pressure ratio and rotational speed on the leakage flow and cavity pressure characteristics of the rotating staggered labyrinth seal were investigated by means of experimental measurements and numerical simulations. The rotating seal test rig with turbine flowmeter and pressure measuring instruments was utilized to investigate the leakage flow of the staggered labyrinth seal at eight pressure ratios and five rotational speeds. The repeatability of the experimental data was demonstrated by three times measurements at different pressure ratios and fixed rotational speed. The three-dimensional Reynolds-averaged Navier–Stokes equations and standard k-epsilon turbulent model were also applied to study the leakage flow characteristics of the staggered labyrinth seal at the experimental conditions. The validation of the numerical approach was verified through comparison of the experimental data. The detailed flow field in the staggered labyrinth seal was illustrated according to the numerical simulations. The experimental and numerical results show that the leakage flow coefficient increases with increasing pressure ratio at the fixed rotational speed and is more sensitive to the smaller pressure ratio. The influence of rotational speed on the leakage flow coefficient is not obvious in the present rotational speed limitations. The cavity pressure coefficient in the staggered labyrinth seal decreases and is significantly influenced by the cavity structure along the flow direction. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...] [article] Effects of pressure ratio and rotational speed on leakage flow and cavity pressure in the staggered labyrinth seal [texte imprimé] / Zhigang Li, Auteur ; Jun Li, Auteur ; Xin Yan, Auteur . - 2012 . - 06 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 06 p. Mots-clés : Flow  simulation  Flowmeters  Navier-Stokes  equations  Numerical  analysis  Pressure  measurement  Rotational  flow  Seals  (stoppers)  Turbines  Turbulence Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Effects of pressure ratio and rotational speed on the leakage flow and cavity pressure characteristics of the rotating staggered labyrinth seal were investigated by means of experimental measurements and numerical simulations. The rotating seal test rig with turbine flowmeter and pressure measuring instruments was utilized to investigate the leakage flow of the staggered labyrinth seal at eight pressure ratios and five rotational speeds. The repeatability of the experimental data was demonstrated by three times measurements at different pressure ratios and fixed rotational speed. The three-dimensional Reynolds-averaged Navier–Stokes equations and standard k-epsilon turbulent model were also applied to study the leakage flow characteristics of the staggered labyrinth seal at the experimental conditions. The validation of the numerical approach was verified through comparison of the experimental data. The detailed flow field in the staggered labyrinth seal was illustrated according to the numerical simulations. The experimental and numerical results show that the leakage flow coefficient increases with increasing pressure ratio at the fixed rotational speed and is more sensitive to the smaller pressure ratio. The influence of rotational speed on the leakage flow coefficient is not obvious in the present rotational speed limitations. The cavity pressure coefficient in the staggered labyrinth seal decreases and is significantly influenced by the cavity structure along the flow direction. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...]

In-cylinder equivalence ratio measurements in an EGR equipped engine / Sreenath B. Gupta in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 133 N° 11 (Novembre 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 05 p. Titre : In-cylinder equivalence ratio measurements in an EGR equipped engine Type de document : texte imprimé Auteurs : Sreenath B. Gupta, Auteur ; Bipin Bihari, Auteur ; Munidhar Biruduganti, Auteur Année de publication : 2012 Article en page(s) : 05 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Combustion  Engine  cylinders  Exhaust  systems  Ignition  Internal  combustion  engines  Laser  beam  effects Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : A single-cylinder natural gas fueled engine equipped with an exhaust gas recirculation (EGR) system was ignited using a laser. The broadband emission from the spark kernel was spectrally resolved, and the peaks corresponding to Halpha, N, and O atoms were measured for a range of conditions with global equivalence ratios ranging between 0.6 and 1.0 and for exhaust gas recirculation fractions up to 29%. The (Halpha/O) and (Halpha/N) peak intensity ratios from the spectral scans correlated extremely well (R2>0.97) with local oxygen based equivalence ratios. Appropriate relations were developed to relate such values to global equivalence ratios and the EGR rate. For a homogeneous intake charge, the present laser induced breakdown spectroscopy diagnostic enables an estimation of one of the two values, global equivalence ratio or EGR rate, with the knowledge of the other. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...] [article] In-cylinder equivalence ratio measurements in an EGR equipped engine [texte imprimé] / Sreenath B. Gupta, Auteur ; Bipin Bihari, Auteur ; Munidhar Biruduganti, Auteur . - 2012 . - 05 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 05 p. Mots-clés : Combustion  Engine  cylinders  Exhaust  systems  Ignition  Internal  combustion  engines  Laser  beam  effects Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : A single-cylinder natural gas fueled engine equipped with an exhaust gas recirculation (EGR) system was ignited using a laser. The broadband emission from the spark kernel was spectrally resolved, and the peaks corresponding to Halpha, N, and O atoms were measured for a range of conditions with global equivalence ratios ranging between 0.6 and 1.0 and for exhaust gas recirculation fractions up to 29%. The (Halpha/O) and (Halpha/N) peak intensity ratios from the spectral scans correlated extremely well (R2>0.97) with local oxygen based equivalence ratios. Appropriate relations were developed to relate such values to global equivalence ratios and the EGR rate. For a homogeneous intake charge, the present laser induced breakdown spectroscopy diagnostic enables an estimation of one of the two values, global equivalence ratio or EGR rate, with the knowledge of the other. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...]

Experimental test rig with results on liquid atomization by slinger injectors / Carmen Sescu in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 133 N° 11 (Novembre 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 04 p. Titre : Experimental test rig with results on liquid atomization by slinger injectors Type de document : texte imprimé Auteurs : Carmen Sescu, Auteur ; Bogdan R. Kucinschi, Auteur ; Abdollah A. Afjeh, Auteur Année de publication : 2012 Article en page(s) : 04 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Drops  Fuel  systems  Gas  turbines Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : In this work, a rotary atomizer, referred to as a slinger injector, is investigated. An experimental setup has been designed to model the environment of the combustion chamber, and an optical measurement system has been implemented to analyze the liquid atomization provided by the slinger injector. In actual small gas turbines, a critical aspect is related to the start-up phase, which typically takes place at speeds around 10,000 rpm. The main scope of this research was to study the liquid spray at relatively low velocities. The primary breakup visualization, breakup length measurement, and droplet size measurement were performed for different rotational speeds. Several pictures of liquid breakup are included, and various mean and representative diameters are presented. In addition, drop size histograms and cumulative volume distribution curves are also included. The results show a decrease in both the breakup length and the mean droplet sizes with increasing rotational speed. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...] [article] Experimental test rig with results on liquid atomization by slinger injectors [texte imprimé] / Carmen Sescu, Auteur ; Bogdan R. Kucinschi, Auteur ; Abdollah A. Afjeh, Auteur . - 2012 . - 04 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 04 p. Mots-clés : Drops  Fuel  systems  Gas  turbines Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : In this work, a rotary atomizer, referred to as a slinger injector, is investigated. An experimental setup has been designed to model the environment of the combustion chamber, and an optical measurement system has been implemented to analyze the liquid atomization provided by the slinger injector. In actual small gas turbines, a critical aspect is related to the start-up phase, which typically takes place at speeds around 10,000 rpm. The main scope of this research was to study the liquid spray at relatively low velocities. The primary breakup visualization, breakup length measurement, and droplet size measurement were performed for different rotational speeds. Several pictures of liquid breakup are included, and various mean and representative diameters are presented. In addition, drop size histograms and cumulative volume distribution curves are also included. The results show a decrease in both the breakup length and the mean droplet sizes with increasing rotational speed. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...]

Integrated power recovery using Markov modeling / Shawn Rodgers in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 133 N° 11 (Novembre 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 04 p. Titre : Integrated power recovery using Markov modeling Type de document : texte imprimé Auteurs : Shawn Rodgers, Auteur ; Coral Betancourt, Auteur ; Ernie Kee, Auteur Année de publication : 2012 Article en page(s) : 04 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Heat  recovery  Markov  processes  Nuclear  power  stations  Nuclear  reactor  steam  generators Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The solution to a Markov chain modeling electric power supply to critical equipment in a typical four-loop pressurized water reactor following a loss of offsite power event is compared with a convolution method. The standard “convolution integral” approach is described, and an alternative methodology based on a Markov model is illustrated. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...] [article] Integrated power recovery using Markov modeling [texte imprimé] / Shawn Rodgers, Auteur ; Coral Betancourt, Auteur ; Ernie Kee, Auteur . - 2012 . - 04 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 133 N° 11 (Novembre 2011) . - 04 p. Mots-clés : Heat  recovery  Markov  processes  Nuclear  power  stations  Nuclear  reactor  steam  generators Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The solution to a Markov chain modeling electric power supply to critical equipment in a typical four-loop pressurized water reactor following a loss of offsite power event is compared with a convolution method. The standard “convolution integral” approach is described, and an alternative methodology based on a Markov model is illustrated. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...]

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