The Experts below are selected from a list of 8280 Experts worldwide ranked by ideXlab platform
Aldo Steinfeld - One of the best experts on this subject based on the ideXlab platform.
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optical and thermal analysis of a Pressurized Air receiver cluster for a 50 mwe solar power tower
Journal of Solar Energy Engineering-transactions of The Asme, 2015Co-Authors: Illias Hischier, Peter Poživil, Aldo SteinfeldAbstract:The optical design and thermal performance of a solar power tower system using an array of high-temperature Pressurized Air-based solar receivers is analyzed for Brayton, recuperated, and combined Brayton–Rankine cycles. A 50 MWe power tower system comprising a cluster of 500 solar receiver modules, each attached to a hexagon-shaped secondary concentrator and arranged side-by-side in a honeycomb-type structure following a spherical fly-eye optical configuration, can yield a peak solar-to-electricity efficiency of 37%.
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numerical heat transfer analysis of a 50 kwth Pressurized Air solar receiver
Journal of Solar Energy Engineering-transactions of The Asme, 2015Co-Authors: Peter Poživil, Simon Ackermann, Aldo SteinfeldAbstract:A high-temperature Pressurized-Air solar receiver, designed for driving a Brayton cycle, consists of a cylindrical SiC cavity and a concentric annular reticulated porous ceramic (RPC) foam enclosed by a steel pressure vessel. Concentrated solar energy is absorbed by the cavity and transferred to the Pressurized Air flowing across the RPC by combined conduction, convection, and radiation. The governing mass, momentum, and energy conservation equations are numerically solved by coupled Monte Carlo (MC) and finite volume (FV) techniques. Model validation was accomplished with experimental data obtained with a 50 kWth modular solar receiver prototype. The model is applied to elucidate the major heat loss mechanisms and to study the impact on the solar receiver performance caused by changes in process conditions, material properties, and geometry. For an outlet Air temperature range 700-1000€‰°C and pressure range 4-15 bar, the thermal efficiency - defined as the ratio of the enthalpy change of the Air flow divided by the solar radiative power input through the aperture - exceeds 63% and can be further improved via geometry optimization. Reradiation is the dominant heat loss.
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A Pressurized Air Receiver for Solar-driven Gas Turbines☆
Energy Procedia, 2014Co-Authors: Peter Poživil, V. Aga, A. Zagorskiy, Aldo SteinfeldAbstract:Abstract A Pressurized Air-based solar receiver is considered for power generation via gas turbines using concentrated solar energy. The modular solar receiver is designed for heating compressed Air to the entrance conditions of a gas turbine in the pressure range 4 – 30 bar and temperature range 800 – 1200 °C. The development work involved the design, fabrication, testing, and modelling of a 3 kWth and a 35 kWth solar receiver prototypes. System integration of an array of modular solar receivers with fossil-fuel hybridization was analysed.
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a modular ceramic cavity receiver for high temperature high concentration solar applications
Journal of Solar Energy Engineering-transactions of The Asme, 2012Co-Authors: Illias Hischier, Peter Poživil, Aldo SteinfeldAbstract:A high-temperature Pressurized Air-based receiver is considered as a module for power generation via solar-driven gas turbines. A set of silicon carbide cavity-receivers attached to a compound parabolic concentrator (CPC) are tested on a solar tower at stagnation conditions for 35 kW solar radiative power input under mean solar concentration ratios of 2000 suns and nominal temperatures up to 1600 K. A heat transfer model coupling radiation, conduction, and convection is formulated by Monte Carlo ray-tracing, finite volume, and finite element techniques, and validated in terms of experimentally measured temperatures. The model is applied to elucidate the effect of material properties, geometry, and reflective coatings on the cavity's thermal and structural performances.
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Experimental and Numerical Analyses of a Pressurized Air Receiver for Solar-Driven Gas Turbines
Volume 7: Fluid Flow Heat Transfer and Thermal Systems Parts A and B, 2010Co-Authors: Illias Hischier, Pascal Leumann, Aldo SteinfeldAbstract:A high-temperature Pressurized Air-based receiver for power generation via solar-driven gas turbines is experimentally and theoretically examined. It consists of an annular reticulate porous ceramic (RPC) foam concentric with an inner cylindrical cavity-receiver exposed to concentrated solar radiation. Absorbed heat is transferred by combined conduction, radiation, and convection to the Pressurized Air flowing across the RPC. The governing steady-state mass, momentum and energy conservation equations are formulated and solved numerically by coupled Finite Volume and Monte Carlo techniques. Validation is accomplished with experimental results using a 1 kW solar receiver prototype subjected to average solar radiative fluxes in the range 1870–4360 kW m−2 . Experimentation was carried out with Air and helium as working fluids, heated from ambient temperature up to 1335 K at an absolute operating pressure of 5 bars.Copyright © 2010 by ASME
Gilles Flamant - One of the best experts on this subject based on the ideXlab platform.
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design and optimization of baffled fluid distributor for realizing target flow distribution in a tubular solar receiver
Energy, 2017Co-Authors: Gilles FlamantAbstract:This paper presents an original study on the design and optimization of baffled fluid distributor for the realization of optimal fluid flow distribution in a tubular solar receiver. The basic idea is to install a perforated baffle in the inlet fluid distributor and to optimize the configuration of orifices on the baffle so as to approach the target flow distribution among downstream parallel tubes. A Pressurized-Air solar receiver comprising of 45 parallel tubes is used for study, with copper or Inconel 600 used as the filling material.
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fluid flow distribution optimization for minimizing the peak temperature of a tubular solar receiver
Energy, 2015Co-Authors: Gilles FlamantAbstract:High temperature solar receiver is a core component of solar thermal power plants. However, non-uniform solar irradiation on the receiver walls and flow maldistribution of heat transfer fluid inside the tubes may cause the excessive peak temperature, consequently leading to the reduced lifetime. This paper presents an original CFD (computational fluid dynamics)-based evolutionary algorithm to determine the optimal fluid distribution in a tubular solar receiver for the minimization of its peak temperature. A Pressurized-Air solar receiver comprising of 45 parallel tubes subjected to a Gaussian-shape net heat flux absorbed by the receiver is used for study. Two optimality criteria are used for the algorithm: identical outlet fluid temperatures and identical temperatures on the centerline of the heated surface. The influences of different filling materials and thermal contact resistances on the optimal fluid distribution and on the peak temperature reduction are also evaluated and discussed.
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Micro-channel Pressurized-Air solar receiver based on compact heat exchanger concept
Solar Energy, 2013Co-Authors: Qi Li, Nathan Guérin De Tourville, Xigang Yuan, Gilles FlamantAbstract:Abstract This paper investigates the thermal performance of Pressurized Air solar receiver for applications in concentrating solar power (CSP) systems. The design is imagined and manufactured based on compact heat exchanger (CHE) concept. An experimental set-up has been built and a series of experiments are carried out under realistic concentrated solar irradiation conditions. The performances of the micro-channel Pressurized Air solar receivers have been studied in the following parameter ranges: pressure, 2–6 bar; Air mass flow rates, 0.431–0.862 g s−1, solar flux density 170–470 kW m−2 and temperature elevation, 100–360 °C. Derived heat transfer coefficients reach 750 W m−2 K−1.
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solar field efficiency and electricity generation estimations for a hybrid solar gas turbine project in france
Journal of Solar Energy Engineering-transactions of The Asme, 2008Co-Authors: Pierre Garcia, Gilles Flamant, Alain Ferriere, Philippe Costerg, Robert Soler, Bruno GagnepainAbstract:The production of electricity with gas turbine and solar energy project aims to install at the Themis site (Targasonne, France) a prototype of hybrid solar/fossil gas-turbine system for electricity generation. The system features a 3800 kW th Pressurized Air solar receiver combined with a fossil backup feeding a recuperated 1400 kW e Turbomeca gas turbine with an external combustion chamber.
Peter Poživil - One of the best experts on this subject based on the ideXlab platform.
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optical and thermal analysis of a Pressurized Air receiver cluster for a 50 mwe solar power tower
Journal of Solar Energy Engineering-transactions of The Asme, 2015Co-Authors: Illias Hischier, Peter Poživil, Aldo SteinfeldAbstract:The optical design and thermal performance of a solar power tower system using an array of high-temperature Pressurized Air-based solar receivers is analyzed for Brayton, recuperated, and combined Brayton–Rankine cycles. A 50 MWe power tower system comprising a cluster of 500 solar receiver modules, each attached to a hexagon-shaped secondary concentrator and arranged side-by-side in a honeycomb-type structure following a spherical fly-eye optical configuration, can yield a peak solar-to-electricity efficiency of 37%.
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numerical heat transfer analysis of a 50 kwth Pressurized Air solar receiver
Journal of Solar Energy Engineering-transactions of The Asme, 2015Co-Authors: Peter Poživil, Simon Ackermann, Aldo SteinfeldAbstract:A high-temperature Pressurized-Air solar receiver, designed for driving a Brayton cycle, consists of a cylindrical SiC cavity and a concentric annular reticulated porous ceramic (RPC) foam enclosed by a steel pressure vessel. Concentrated solar energy is absorbed by the cavity and transferred to the Pressurized Air flowing across the RPC by combined conduction, convection, and radiation. The governing mass, momentum, and energy conservation equations are numerically solved by coupled Monte Carlo (MC) and finite volume (FV) techniques. Model validation was accomplished with experimental data obtained with a 50 kWth modular solar receiver prototype. The model is applied to elucidate the major heat loss mechanisms and to study the impact on the solar receiver performance caused by changes in process conditions, material properties, and geometry. For an outlet Air temperature range 700-1000€‰°C and pressure range 4-15 bar, the thermal efficiency - defined as the ratio of the enthalpy change of the Air flow divided by the solar radiative power input through the aperture - exceeds 63% and can be further improved via geometry optimization. Reradiation is the dominant heat loss.
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A Pressurized Air Receiver for Solar-driven Gas Turbines☆
Energy Procedia, 2014Co-Authors: Peter Poživil, V. Aga, A. Zagorskiy, Aldo SteinfeldAbstract:Abstract A Pressurized Air-based solar receiver is considered for power generation via gas turbines using concentrated solar energy. The modular solar receiver is designed for heating compressed Air to the entrance conditions of a gas turbine in the pressure range 4 – 30 bar and temperature range 800 – 1200 °C. The development work involved the design, fabrication, testing, and modelling of a 3 kWth and a 35 kWth solar receiver prototypes. System integration of an array of modular solar receivers with fossil-fuel hybridization was analysed.
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a modular ceramic cavity receiver for high temperature high concentration solar applications
Journal of Solar Energy Engineering-transactions of The Asme, 2012Co-Authors: Illias Hischier, Peter Poživil, Aldo SteinfeldAbstract:A high-temperature Pressurized Air-based receiver is considered as a module for power generation via solar-driven gas turbines. A set of silicon carbide cavity-receivers attached to a compound parabolic concentrator (CPC) are tested on a solar tower at stagnation conditions for 35 kW solar radiative power input under mean solar concentration ratios of 2000 suns and nominal temperatures up to 1600 K. A heat transfer model coupling radiation, conduction, and convection is formulated by Monte Carlo ray-tracing, finite volume, and finite element techniques, and validated in terms of experimentally measured temperatures. The model is applied to elucidate the effect of material properties, geometry, and reflective coatings on the cavity's thermal and structural performances.
Ya E Krasik - One of the best experts on this subject based on the ideXlab platform.
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electron emission mechanism during the nanosecond high voltage pulsed discharge in Pressurized Air
Applied Physics Letters, 2012Co-Authors: Dmitry Levko, Shurik Yatom, V Vekselman, Ya E KrasikAbstract:A comparison between the results of x-ray absorption spectroscopy of runaway electrons (RAEs) generated during nanosecond timescale high-voltage (HV) gas discharge and the simulated attenuation of the x-ray flux produced by the runaway electron spectrum calculated using particle-in-cell numerical modeling of such a type of discharge is presented. The particle-in-cell simulation considered the field and explosive emissions (EEs) of the electrons from the cathode. It is shown that the field emission is the dominant emission mechanism for the short-duration ( 5 ns) high-voltage pulses, the explosive emission is likely to play a significant role.
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time resolved investigation of nanosecond discharge in dense gas sustained by short and long high voltage pulse
EPL, 2011Co-Authors: Shurik Yatom, Dmitry Levko, V Vekselman, J Z Gleizer, V T Gurovich, E Hupf, Y Hadas, Ya E KrasikAbstract:The results of experimental and numerical studies of the generation of runaway electrons (RAE) in a Pressurized Air-filled diode under the application of 20 ns, 5 ns and 1 ns duration high-voltage pulses with an amplitude up to 160 kV are presented. It is shown that with a 1 ns pulse, RAE with energy ≥20 keV reach the anode prior to the formation of the plasma channel between the cathode and anode. Conversely, with 20 ns or 5 ns pulses, RAE with energy ≥20 keV were obtained at the anode only after the formation of the plasma channel. In addition, the high- and low-impedance stages of the development of the discharge were found. Finally, a comparison between experimental and numerical simulation results is presented.
R Couturier - One of the best experts on this subject based on the ideXlab platform.
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experimentation of a high temperature thermal energy storage prototype using phase change materials for the thermal protection of a Pressurized Air solar receiver
Energy Procedia, 2014Co-Authors: D Verdier, A Ferriere, Q Falcoz, F Siros, R CouturierAbstract:Abstract The work addresses the issue of fast variations of temperature of a central solar receiver under cloud covering. A specific attention is paid to the situation of Hybrid Solar Gas Turbine (HSGT) systems using Pressurized Air as Heat Transfer Fluid (HTF), as it is considered in the Pegase project (France). A Thermal Energy Storage (TES) unit integrated in the receiver is proposed for smoothing the variation of temperature. The technology is based on the utilization of both Phase Change Material (PCM) and metallic fins in order to enhance charge and discharge capability of the storage unit. A test-bench is designed with copper fins and is experienced with paraffin wax and with Li 2 CO 3 successively as PCMs. In the same time, the test unit is modeled and the charging and discharging modes are simulated. The results show that the full charging is achieved in about 4 hours starting from 700 °C when the receiver is maintained at 900 °C, whereas the discharge from 900 °C to 700 °C is achieved in 2.5 hours.
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thermal performances of a high temperature Air solar absorber based on compact heat exchange technology
Journal of Solar Energy Engineering-transactions of The Asme, 2011Co-Authors: B Grange, Alain Ferriere, R Couturier, D Bellard, M Vrinat, F Pra, Yilin FanAbstract:In the framework of the French PEGASE project (Production of Electricity by GAs turbine and Solar Energy), CNRS/PROMES laboratory is developing a 4 MWth Pressurized Air solar receiver with a surface absorber based on a compact heat exchanger technology. The first step of this development consists in designing and testing a pilot scale (1/10 scale, e.g., 360 kWth) solar receiver based on a metallic surface absorber. This paper briefly presents the hydraulic and thermal performances of the innovative Pressurized Air solar absorber developed in a previous work. The goal is to be capable of preheating Pressurized Air from 350 °C at the inlet to 750 °C at the outlet, with a maximum pressure drop of 300 mbar. The receiver is a cavity of square aperture 120 cm × 120 cm and 1 m deepness with an average concentration in the aperture of more than 300. The square shaped aperture is chosen due to the small scale of the receiver; indeed, the performances are not enhanced that much with a round aperture, while the manufacturability is much more complicated. However in the perspective of PEGASE, a round aperture is likely to be used. The back of the cavity is covered by modules arranged in two series making the modular and multistage absorber. The thermal performances of one module are considered to simulate the thermal exchange within the receiver and to estimate the energy efficiency of this receiver. The results of the simulation show that the basic design yields an Air outlet temperature of 739 °C under design operation conditions (1000 W/m2 solar irradiation, 0.8 kg/s Air flow rate). Using the cavity walls as Air preheating elements allows increasing the Air outlet temperature above 750 °C as well as the energy efficiency up to 81% but at the cost of a critical absorber wall temperature. However, this wall temperature can be controlled by applying an aiming point strategy with the heliostat field.
