The Experts below are selected from a list of 141 Experts worldwide ranked by ideXlab platform
Peter G. Loutzenhiser - One of the best experts on this subject based on the ideXlab platform.
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aluminum doped calcium manganite particles for solar thermochemical energy storage reactor design particle characterization and heat and mass transfer modeling
International Journal of Heat and Mass Transfer, 2020Co-Authors: Andrew J Schrader, Evan H Bush, Devesh Ranjan, Peter G. LoutzenhiserAbstract:Abstract A two-step Cycle was considered for solar thermochemical energy storage based on particulate aluminum-doped calcium manganite reduction/oxidation reactions for direct integration into Air-Brayton Cycles. The two steps encompass (1) the storage of concentrated solar irradiation within endothermic reduction of aluminum-doped calcium manganite and (2) the delivery of heat to an Air-Brayton Cycle via exothermic re-oxidation of oxygen-deficient aluminum-doped calcium magnanite. A 5 kWth scale solar thermochemical reactor operating under vacuum was designed, modeled, and optimized to thermally reduce a continuous, gravity-driven flow of aluminum-doped calcium manganite particles. The granular flows were characterized in a tilt-flow rig, and particle image velocimetry was used to determine flow properties via frictional and velocity scaling relationships. Flow properties were integrated into a detailed heat and mass transfer model of the solar thermochemical reactor. A reactor design with 31° inclination angle, 230 g/min of particles, and 5.2 kWth radiative input from the high-flux solar simulator was found to produce an outlet flow temperature of 1158 K, with stoichiometric deviations of 0.076 and a storage efficiency of 0.628 while avoiding particle overheating and promoting longer particle residence times.
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Experimental demonstration of a 5 kWth granular-flow reactor for solar thermochemical energy storage with aluminum-doped calcium manganite particles
Applied Thermal Engineering, 2020Co-Authors: Andrew J Schrader, Gretchen L Schieber, Andrea Ambrosini, Peter G. LoutzenhiserAbstract:Abstract A two-step Cycle was considered for solar thermochemical energy storage based on aluminum-doped calcium manganite reduction/oxidation reactions for direct integration into Air Brayton Cycles. The two steps encompassed (1) the storage of concentrated solar direct irradiation via the thermal reduction of aluminum-doped calcium manganite and (2) the delivery of heat to an Air-Brayton Cycle via re-oxidation of oxygen-deficient aluminum-doped calcium manganite. The re-oxidized aluminum-doped calcium manganite was fed back to the first step to complete the Cycle. A 5 kWth solar thermochemical reactor operating under vacuum was fabricated and tested to examine the first Cycle reduction step. Reactor operating conditions and high-flux solar simulator control were tuned for continuous reactor operation with particle temperatures >1073 K. Continuous operation was achieved using intermittent, dense granular flows. A maximum absorption efficiency of 64.7% was demonstrated, accounting for both sensible and chemical heat storage.
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Solar electricity via an Air Brayton Cycle with an integrated two-step thermochemical Cycle for heat storage based on Fe2O3/Fe3O4 redox reactions: Thermodynamic and kinetic analyses
Solar Energy, 2018Co-Authors: H. Evan Bush, Peter G. LoutzenhiserAbstract:Abstract Solar electricity production via an Air Brayton Cycle is considered with integrated thermochemical energy storage. The storage is realized via a two-step solar thermochemical Cycle based on Fe2O3/Fe3O4 reduction-oxidation reactions, encompassing (1) the thermal reduction of Fe2O3 to Fe3O4 and O2 driven by concentrated solar irradiation under vacuum; and (2) the exothermic oxidation of Fe3O4 with a compressed Air stream back to Fe2O3. The steps may be decoupled, resulting in a high temperature, pressurized Airflow that is expanded across a turbine to produce on-demand electricity. A thermodynamic analysis of the system determined a maximum Cycle efficiency of 46.0% at a solar concentration ratio of 4000 suns, an oxidation pressure of 30 bar, and an approximately 5:1 molar flow rate ratio of Air to solid Fe2O3 exiting the re-oxidizer. Chemical kinetics for the thermal reduction of Fe2O3 were determined between approximately 1400 and 1700 K using non-isothermal thermogravimetry with heating rates between 10 and 20 K·s−1 and O2 partial pressures between 0 and 0.05 bar. The rate-limiting reaction mechanism was determined to be nucleation, and kinetic parameters were resolved using an Avrami-Erofe’ev nucleation model with a reaction order of 1.264 ± 0.010. The rate constant followed an Arrhenius-type temperature dependency with an apparent activation energy of 487.0 ± 3.6 kJ·mol−1 and pre-exponential factor 2.768 ± 0.783·1014 s−1. A power-law dependence on O2 partial pressure of order 8.317 ± 0.233 was determined. Non-isothermal thermogravimetry to examine the oxidation of Fe3O4 to Fe2O3 revealed multiple kinetic regimes, and isothermal thermogravimetry showed the reaction proceeded rapidly, within 20 s, at temperatures greater than 673 K. Solid characterization was carried out using scanning electron microscopy and x-ray powder diffractometry up to temperatures of 1073 K to verify initial and final sample compositions and structures.
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solar electricity via an Air Brayton Cycle with an integrated two step thermochemical Cycle for heat storage based on co 3 o 4 coo redox reactions iii solar thermochemical reactor design and modeling
Solar Energy, 2017Co-Authors: Andrew J Schrader, Gretchen L Schieber, Gianmarco De Dominicis, Peter G. LoutzenhiserAbstract:Abstract A two-step solar thermochemical Cycle based on Co3O4/CoO redox reactions integrated into an Air Brayton Cycle is considered for thermochemical heat storage. The two-step Cycle encompasses (1) the thermal reduction of Co3O4 to CoO and O2 driven by concentrated solar irradiation and (2) the re-oxidation of CoO with O2 to Co3O4, releasing heat and completing the Cycle. An evacuated horizontal solar thermochemical reactor is proposed with an inclined slope and quartz window for promoting direct irradiation of dense, granular Co3O4/CoO flows. Mechanical analysis of flat and spherical quartz window designs for a 5 kWth scale prototype was performed to ensure window stability. Detailed mass and heat transfer analysis for a 5 kWth scale prototype was performed coupling Monte Carlo ray tracing for radiative heat exchange to the energy balances for the bed and the reactor. A parametric study of the reactor design was performed with varying cavity depth, particle inlet temperature, and solar concentration ratio. The optimal solar reactor design maximized conversion of Co3O4 to CoO and particle outlet temperature while preventing particle overheating and achieved a Co3O4 to CoO conversion of 0.91, particle outlet temperature of 1385 K, maximum flow temperature of 1572 K, and absorption efficiency of 0.76.
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A review of the state-of-the-art in solar-driven gasification processes with carbonaceous materials
Solar Energy, 2017Co-Authors: Peter G. Loutzenhiser, Alexander P MuroyamaAbstract:Abstract Gasification of carbonaceous feedstock with process heat derived from concentrated solar irradiation has been shown as a promising renewable pathway towards producing synthesis gas (mixtures of H2/CO and some CO2). The carbonaceous feedstock is upgraded in calorific content equal to the enthalpy change of the endothermic reaction, which results in the net storage of solar energy in a chemical form. The process is carbon-neutral when biomass is used and the feedstock is transformed into a fuel with applications to more efficient processes (e.g., Air-Brayton Cycle), and the resulting syngas can be converted to liquid hydrocarbon fuels via know catalytic routes. A comprehensive summary is provided of the state-of-the-art in solar gasification, including thermodynamic and kinetic analyses and thermochemical reactor modeling, fabrication and testing for a range of carbonaceous feedstocks.
Andrew J Schrader - One of the best experts on this subject based on the ideXlab platform.
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aluminum doped calcium manganite particles for solar thermochemical energy storage reactor design particle characterization and heat and mass transfer modeling
International Journal of Heat and Mass Transfer, 2020Co-Authors: Andrew J Schrader, Evan H Bush, Devesh Ranjan, Peter G. LoutzenhiserAbstract:Abstract A two-step Cycle was considered for solar thermochemical energy storage based on particulate aluminum-doped calcium manganite reduction/oxidation reactions for direct integration into Air-Brayton Cycles. The two steps encompass (1) the storage of concentrated solar irradiation within endothermic reduction of aluminum-doped calcium manganite and (2) the delivery of heat to an Air-Brayton Cycle via exothermic re-oxidation of oxygen-deficient aluminum-doped calcium magnanite. A 5 kWth scale solar thermochemical reactor operating under vacuum was designed, modeled, and optimized to thermally reduce a continuous, gravity-driven flow of aluminum-doped calcium manganite particles. The granular flows were characterized in a tilt-flow rig, and particle image velocimetry was used to determine flow properties via frictional and velocity scaling relationships. Flow properties were integrated into a detailed heat and mass transfer model of the solar thermochemical reactor. A reactor design with 31° inclination angle, 230 g/min of particles, and 5.2 kWth radiative input from the high-flux solar simulator was found to produce an outlet flow temperature of 1158 K, with stoichiometric deviations of 0.076 and a storage efficiency of 0.628 while avoiding particle overheating and promoting longer particle residence times.
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Experimental demonstration of a 5 kWth granular-flow reactor for solar thermochemical energy storage with aluminum-doped calcium manganite particles
Applied Thermal Engineering, 2020Co-Authors: Andrew J Schrader, Gretchen L Schieber, Andrea Ambrosini, Peter G. LoutzenhiserAbstract:Abstract A two-step Cycle was considered for solar thermochemical energy storage based on aluminum-doped calcium manganite reduction/oxidation reactions for direct integration into Air Brayton Cycles. The two steps encompassed (1) the storage of concentrated solar direct irradiation via the thermal reduction of aluminum-doped calcium manganite and (2) the delivery of heat to an Air-Brayton Cycle via re-oxidation of oxygen-deficient aluminum-doped calcium manganite. The re-oxidized aluminum-doped calcium manganite was fed back to the first step to complete the Cycle. A 5 kWth solar thermochemical reactor operating under vacuum was fabricated and tested to examine the first Cycle reduction step. Reactor operating conditions and high-flux solar simulator control were tuned for continuous reactor operation with particle temperatures >1073 K. Continuous operation was achieved using intermittent, dense granular flows. A maximum absorption efficiency of 64.7% was demonstrated, accounting for both sensible and chemical heat storage.
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solar electricity via an Air Brayton Cycle with an integrated two step thermochemical Cycle for heat storage based on co 3 o 4 coo redox reactions iii solar thermochemical reactor design and modeling
Solar Energy, 2017Co-Authors: Andrew J Schrader, Gretchen L Schieber, Gianmarco De Dominicis, Peter G. LoutzenhiserAbstract:Abstract A two-step solar thermochemical Cycle based on Co3O4/CoO redox reactions integrated into an Air Brayton Cycle is considered for thermochemical heat storage. The two-step Cycle encompasses (1) the thermal reduction of Co3O4 to CoO and O2 driven by concentrated solar irradiation and (2) the re-oxidation of CoO with O2 to Co3O4, releasing heat and completing the Cycle. An evacuated horizontal solar thermochemical reactor is proposed with an inclined slope and quartz window for promoting direct irradiation of dense, granular Co3O4/CoO flows. Mechanical analysis of flat and spherical quartz window designs for a 5 kWth scale prototype was performed to ensure window stability. Detailed mass and heat transfer analysis for a 5 kWth scale prototype was performed coupling Monte Carlo ray tracing for radiative heat exchange to the energy balances for the bed and the reactor. A parametric study of the reactor design was performed with varying cavity depth, particle inlet temperature, and solar concentration ratio. The optimal solar reactor design maximized conversion of Co3O4 to CoO and particle outlet temperature while preventing particle overheating and achieved a Co3O4 to CoO conversion of 0.91, particle outlet temperature of 1385 K, maximum flow temperature of 1572 K, and absorption efficiency of 0.76.
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solar electricity via an Air Brayton Cycle with an integrated two step thermochemical Cycle for heat storage based on co3o4 coo redox reactions ii kinetic analyses
Solar Energy, 2015Co-Authors: Alexander P Muroyama, Andrew J Schrader, Peter G. LoutzenhiserAbstract:Abstract A two-step solar thermochemical Cycle based on Co3O4/CoO redox reactions integrated into an Air Brayton Cycle is considered for thermochemical heat storage. The two-step Cycle encompasses (1) the thermolysis of Co3O4 to CoO and O2 driven by concentrated solar irradiation and (2) the re-oxidation of CoO with O2 to Co3O4, releasing heat and completing the Cycle. The Cycle steps can be decoupled, allowing for thermochemical heat storage and integration into an Air Brayton Cycle for continuous electricity production. Kinetic analyses to identify the rate limiting mechanisms and determine kinetic parameters for both the thermolysis of Co3O4 and the re-oxidation of CoO with O2 were performed using a combination of isothermal and non-isothermal thermogravimetry. The Co3O4 thermolysis between 1113 and 1213 K followed an Avrami–Erofeyev nucleation model with an Avrami constant of 1.968 and apparent activation energy of 247.21 kJ mol−1. The O2 partial pressure dependence between 0% and 20% O2–Ar was determined with a power rate law, resulting in a reaction order of 1.506. Ionic diffusion was the rate limiting step for CoO oxidation between 450 and 750 K with an apparent activation energy of 58.07 kJ mol−1 and no evident dependence on O2 concentration between 5% and 100% O2–Ar. Solid characterization was performed using scanning electron microscopy and X-ray powder diffraction.
Gretchen L Schieber - One of the best experts on this subject based on the ideXlab platform.
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Experimental demonstration of a 5 kWth granular-flow reactor for solar thermochemical energy storage with aluminum-doped calcium manganite particles
Applied Thermal Engineering, 2020Co-Authors: Andrew J Schrader, Gretchen L Schieber, Andrea Ambrosini, Peter G. LoutzenhiserAbstract:Abstract A two-step Cycle was considered for solar thermochemical energy storage based on aluminum-doped calcium manganite reduction/oxidation reactions for direct integration into Air Brayton Cycles. The two steps encompassed (1) the storage of concentrated solar direct irradiation via the thermal reduction of aluminum-doped calcium manganite and (2) the delivery of heat to an Air-Brayton Cycle via re-oxidation of oxygen-deficient aluminum-doped calcium manganite. The re-oxidized aluminum-doped calcium manganite was fed back to the first step to complete the Cycle. A 5 kWth solar thermochemical reactor operating under vacuum was fabricated and tested to examine the first Cycle reduction step. Reactor operating conditions and high-flux solar simulator control were tuned for continuous reactor operation with particle temperatures >1073 K. Continuous operation was achieved using intermittent, dense granular flows. A maximum absorption efficiency of 64.7% was demonstrated, accounting for both sensible and chemical heat storage.
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solar electricity via an Air Brayton Cycle with an integrated two step thermochemical Cycle for heat storage based on co 3 o 4 coo redox reactions iii solar thermochemical reactor design and modeling
Solar Energy, 2017Co-Authors: Andrew J Schrader, Gretchen L Schieber, Gianmarco De Dominicis, Peter G. LoutzenhiserAbstract:Abstract A two-step solar thermochemical Cycle based on Co3O4/CoO redox reactions integrated into an Air Brayton Cycle is considered for thermochemical heat storage. The two-step Cycle encompasses (1) the thermal reduction of Co3O4 to CoO and O2 driven by concentrated solar irradiation and (2) the re-oxidation of CoO with O2 to Co3O4, releasing heat and completing the Cycle. An evacuated horizontal solar thermochemical reactor is proposed with an inclined slope and quartz window for promoting direct irradiation of dense, granular Co3O4/CoO flows. Mechanical analysis of flat and spherical quartz window designs for a 5 kWth scale prototype was performed to ensure window stability. Detailed mass and heat transfer analysis for a 5 kWth scale prototype was performed coupling Monte Carlo ray tracing for radiative heat exchange to the energy balances for the bed and the reactor. A parametric study of the reactor design was performed with varying cavity depth, particle inlet temperature, and solar concentration ratio. The optimal solar reactor design maximized conversion of Co3O4 to CoO and particle outlet temperature while preventing particle overheating and achieved a Co3O4 to CoO conversion of 0.91, particle outlet temperature of 1385 K, maximum flow temperature of 1572 K, and absorption efficiency of 0.76.
Alexander P Muroyama - One of the best experts on this subject based on the ideXlab platform.
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A review of the state-of-the-art in solar-driven gasification processes with carbonaceous materials
Solar Energy, 2017Co-Authors: Peter G. Loutzenhiser, Alexander P MuroyamaAbstract:Abstract Gasification of carbonaceous feedstock with process heat derived from concentrated solar irradiation has been shown as a promising renewable pathway towards producing synthesis gas (mixtures of H2/CO and some CO2). The carbonaceous feedstock is upgraded in calorific content equal to the enthalpy change of the endothermic reaction, which results in the net storage of solar energy in a chemical form. The process is carbon-neutral when biomass is used and the feedstock is transformed into a fuel with applications to more efficient processes (e.g., Air-Brayton Cycle), and the resulting syngas can be converted to liquid hydrocarbon fuels via know catalytic routes. A comprehensive summary is provided of the state-of-the-art in solar gasification, including thermodynamic and kinetic analyses and thermochemical reactor modeling, fabrication and testing for a range of carbonaceous feedstocks.
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solar electricity via an Air Brayton Cycle with an integrated two step thermochemical Cycle for heat storage based on co3o4 coo redox reactions ii kinetic analyses
Solar Energy, 2015Co-Authors: Alexander P Muroyama, Andrew J Schrader, Peter G. LoutzenhiserAbstract:Abstract A two-step solar thermochemical Cycle based on Co3O4/CoO redox reactions integrated into an Air Brayton Cycle is considered for thermochemical heat storage. The two-step Cycle encompasses (1) the thermolysis of Co3O4 to CoO and O2 driven by concentrated solar irradiation and (2) the re-oxidation of CoO with O2 to Co3O4, releasing heat and completing the Cycle. The Cycle steps can be decoupled, allowing for thermochemical heat storage and integration into an Air Brayton Cycle for continuous electricity production. Kinetic analyses to identify the rate limiting mechanisms and determine kinetic parameters for both the thermolysis of Co3O4 and the re-oxidation of CoO with O2 were performed using a combination of isothermal and non-isothermal thermogravimetry. The Co3O4 thermolysis between 1113 and 1213 K followed an Avrami–Erofeyev nucleation model with an Avrami constant of 1.968 and apparent activation energy of 247.21 kJ mol−1. The O2 partial pressure dependence between 0% and 20% O2–Ar was determined with a power rate law, resulting in a reaction order of 1.506. Ionic diffusion was the rate limiting step for CoO oxidation between 450 and 750 K with an apparent activation energy of 58.07 kJ mol−1 and no evident dependence on O2 concentration between 5% and 100% O2–Ar. Solid characterization was performed using scanning electron microscopy and X-ray powder diffraction.
Ali Zare - One of the best experts on this subject based on the ideXlab platform.
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Energy and exergy analysis of a novel turbo-compounding system for supercharging and mild hybridization of a gasoline engine
Journal of Thermal Analysis and Calorimetry, 2020Co-Authors: Farhad Salek, Meisam Babaie, Ali Ghodsi, Seyed Vahid Hosseini, Ali ZareAbstract:Number of hybrid vehicles has increased around the world significantly. Automotive industry is utilizing the hybridization of the powertrain system to achieve better fuel economic and emissions reduction. One of the options recently considered in research for hybridization and downsizing of vehicles is to employ waste heat recovery systems. In this paper, the addition of a turbo-compound system with an Air Brayton Cycle (ABC) to a naturally aspirated engine was studied in AVL BOOST software. In addition, a supercharger was modeled to charge extra Air into the engine and ABC. The engine was first validated against the experimental data prior to turbo-compounding. The energy and exergy analysis was performed to understand the effects of the proposed design at engine rated speed. Results showed that between 16 and 18% increase in engine mechanical power can be achieved by adding turbo-compressor. Furthermore, the recommended ABC system can recover up to 1.1 kW extra electrical power from the engine exhaust energy. The energy and exergy efficiencies were both improved slightly by turbo-compounding and BSFC reduced by nearly 1% with the proposed system. Furthermore, installing the proposed system resulted in increase in backpressure up to approximately 23.8 kPa.
