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Zeyad Alsuhaibani - One of the best experts on this subject based on the ideXlab platform.
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modeling of transient cyclic behavior of a solid Particle thermal energy storage bin for central Receiver applications
Energy Procedia, 2015Co-Authors: Hany Alansary, Syed Noman Danish, Eldwin Djajadiwinata, A M Elleathy, Zeyad AlsuhaibaniAbstract:Abstract One of the emerging thermal energy storage (TES) concepts is the use of solid Particles, which can potentially store thermal energy at temperatures approaching 1000 °C. Efforts are underway to prepare on-sun testing of this concept at King Saud University (Riyadh, Saudi Arabia) as a part of the research activities in a SunShot project led by Sandia National Laboratories. A thorough study of this concept has been conducted and a prototype has been designed. This concept involves the use of proppants (CARBO Accucast ID50K) as the storage medium, and a thick, multilayered, cylindrical-shaped TES bin as the storage bin. Due to the complexity of building this first-of-its-kind TES bin, it was necessary to model the thermal performance of this design prior to completing the construction process. For this reason, a numerical model was built for the TES bin which is capable of determining the amount of energy loss. The model takes into account that, during daytime operation, the charging flow rate is higher than the discharging flow rate to allow the proppants to accumulate within the TES bin over about 7 hours. Once the charging process is completed, the discharging phase – whose duration is about 5 hours – is also modeled, followed by modeling the cooling-down process of the TES bin for 12 hours to complete a 24-hour cycle. This modeling cycle is based on an assumed initial temperature in the interior of the bin. This paper extends the modeling effort to more than one cycle, such that the initial conditions at the beginning of each cycle are based on information obtained from the previous cycle, rather than on assumed values. Results show that multi-cycle modeling is important, since it shows that the assumed initial temperature may not representative and may lead to inaccurate results. Furthermore, lessons learned from the first cycle of operation, especially excessive air leakage into the TES bin during nighttime depletion, help refine modeling of subsequent cycles. Energy loss at the end of the second cycle was found to be 4.3%. While considered large, this value is primarily due to the high surface-to-volume ratio of the prototype TES bin being investigated. Preliminary analysis shows that a utility-scale TES bin using the same concept will have an energy loss of less than 1%, which conforms to the current best practice, and shows that low-cost TES solutions can be used in conjunction with the falling Particle Receiver concept.
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thermal performance evaluation of two thermal energy storage tank design concepts for use with a solid Particle Receiver based solar power tower
Energies, 2014Co-Authors: A M Elleathy, Matthew Golob, Syed Noman Danish, Eldwin Djajadiwinata, S M Jeter, Hany Alansary, S I Abdelkhalik, Jonathan Roop, Abdulaziz Alrished, Zeyad AlsuhaibaniAbstract:This paper presents the results of an extensive study of two thermal energy storage (TES) systems. The goal of the research is to make solar energy cost-competitive with other forms of electricity. A small-scale TES system was first built. The inner to outer layers were made of firebrick (FB), autoclaved aerated concrete (AAC) and reinforced concrete brick (CB). The experiments were conducted at temperatures of up to 1000 °C for sustained periods of time. AAC was found to be prone to cracking at temperatures exceeding 900 °C; as a result, AAC was eliminated from the second TES system. The second, larger-scale TES system was subsequently built of multiple layers of readily available materials, namely, insulating firebrick (IFB), perlite concrete (PC), expansion joint (EJ), and CB. All of the surfaces were instrumented with thermocouples to estimate the heat loss from the system. The temperature was maintained at approximately 800 °C to approximate steady state conditions closely. The steady state heat loss was determined to be approximately 4.4% for a day. The results indicate that high-temperature TES systems can be constructed of readily available materials while meeting the heat loss requirements for a falling Particle Receiver system, thereby contributing to reducing the overall cost of concentrating solar power systems.
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modeling of transient energy loss from a cylindrical shaped solid Particle thermal energy storage tank for central Receiver applications
International Conference on Fuel Cell Science Engineering and Technology FUELCELL Collocated with ASME International Conference on Energy Sustainabili, 2014Co-Authors: Eldwin Djajadiwinata, Syed Noman Danish, A M Elleathy, Hany Alansary, Zeyad AlsuhaibaniAbstract:The use of solid Particles as a heat transfer and thermal energy storage (TES) medium in central Receiver systems has received renewed attention in recent years due to the ability of achieving high temperatures and the potential reduction in Receiver and TES costs. Performance of TES systems is primarily characterized by the percentage of heat loss they allow over a prescribed period of time. Accurate estimation of this parameter requires special attention to the transient nature of the process of charging the TES bin during solar field operation and discharging during nighttime or at periods where solar field operation is interrupted. In this study, a numerical model is built to simulate the charge-discharge cycle of a small cylindrical-shaped TES bin that is currently under construction. This bin is integrated into the tower of an experimental 300-kW (thermal) central Receiver field being built in Riyadh, Saudi Arabia, for solid Particle Receiver research, most notably on-sun testing of the falling Particle Receiver concept within the context of a SunShot project. The model utilizes a type of wall construction that had been previously identified as showing favorable structural characteristics and being able to withstand high temperatures. The model takes into account the anticipated charge-discharge Particle flow rates, and includes an insulating layer at the ceiling of the bin to minimize heat loss by convection and radiation to the Receiver cavity located immediately over the TES bin. Results show that energy loss during the full charge-discharge cycle is 4.9% and 5.9% for a 5-hour and 17-hour discharge period, respectively. While large, these energy loss values are primarily due to the high surface-to-volume ratio of the small TES bin being investigated. Preliminary analysis shows that a utility-scale TES bin using the same concept will have an energy loss of less than 1%.Copyright © 2014 by ASME
Gregory J Kolb - One of the best experts on this subject based on the ideXlab platform.
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CFD Simulation and Performance Analysis of Alternative Designs for High-Temperature Solid Particle Receivers
ASME 2011 5th International Conference on Energy Sustainability Parts A B and C, 2011Co-Authors: Siri S Khalsa, Gregory J Kolb, Nathan P Siegel, Joshua M. Christian, Lars Amsbeck, Marc Röger, Adam C. MoyaAbstract:Direct-absorption solid Particle Receivers are theoretically capable of yielding temperatures in excess of 1000°C, which enables higher efficiency power cycles and lower thermal storage costs. This paper presents rigorous CFD simulations of alternative solid Particle Receiver designs with recirculation to help identify optimal configurations that maximize the Receiver thermal efficiency. The alternative Receiver designs considered are a north-facing cavity Receiver and a face-down surround-field cavity Receiver. The CFD simulations model incident solar radiation from a heliostat field as a boundary condition on the model domain. The CFD simulations also couple convective flow with the thermal and discrete-phase (Particle) solutions, which in turn affects absorption of incident solar radiation and thermal re-radiation within the Receiver. The Receivers are optimized to yield comparable Particle temperatures at the outlets of 750–850°C, heated from an injection temperature of 300°C, and are compared on the basis of thermal efficiency. The CFD simulations yielded thermal efficiencies of the north-facing Receiver at 72.3% (losses were 6.5% radiative and 20.9% convective) and the face-down Receiver at 78.9% (losses were 11.4% radiative and 9.6% convective) at solar noon on March 22. Ongoing efforts are focused on reducing convective and radiative losses from both Receiver configurations.Copyright © 2011 by ASME
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development and evaluation of a prototype solid Particle Receiver on sun testing and model validation
Journal of Solar Energy Engineering-transactions of The Asme, 2010Co-Authors: Natha P Siegel, Siri S Khalsa, Gregory J KolbAbstract:A prototype direct absorption central Receiver, called the solid Particle Receiver (SPR), was built and evaluated on-sun at power levels up to 2.5 MW th at Sandia National Laboratories in Albuquerque, NM. The SPR consists of a 6 m tall cavity through which spherical sintered bauxite Particles are dropped and directly heated with concentrated solar energy. In principle, the Particles can be efficiently heated to a temperature in excess of 900°C, well beyond the stability limit of existing nitrate salt formulations. The heated Particles may then be stored in a way analogous to nitrate salt systems, enabling a dispatchable thermal input to power or fuel production cycles. The focus of this current effort was to provide an experimental basis for the validation of computational models that have been created to support improved designs and further development of the solid Particle Receiver. In this paper we present information on the design and construction of the solid Particle Receiver and discuss the development of a computational fluid dynamics model of the prototype. We also present experimental data and model comparisons for on-sun testing of the Receiver over a range of input power levels from 1.58―2.51 MW th . Model validation is performed using a number of metrics including Particle velocity, exit temperature, and Receiver efficiency. In most cases, the difference between the model predictions and data is less than 10%.
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experimental and simulation study on wind affecting Particle flow in a solar Receiver
Solar Energy, 2010Co-Authors: Kibum Kim, Samir Moujaes, Gregory J KolbAbstract:The solid Particle Receiver (SPR) is a direct absorption central Receiver that can provide a solar interface with thermal storage for thermo-chemical hydrogen production processes requiring heat input at temperatures up to 1000 °C. In operation, a curtain made up of approximately 697 μm ceramic Particles is dropped within the Receiver cavity and directly illuminated by concentrated solar energy. Since the SPR has an open aperture, the flow may be disturbed by high ambient winds. Therefore, the objective of this study was to gain insight into the wind effect on the curtain. Experiments were conducted to understand the wind influence on the Particle flow and loss. The experimental results showed that winds from certain angles of the attack could cause a critical loss of Particles. A MFIX simulation model was developed to validate the experimental results and observation. The simulation has provided us with better understanding on the wind effects.
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a study of solid Particle flow characterization in solar Particle Receiver
Solar Energy, 2009Co-Authors: Nathan P Siegel, Gregory J Kolb, Vijayarangan Rangaswamy, Samir MoujaesAbstract:Abstract The solid Particle Receiver (SPR) is a direct absorption Receiver in which solar energy heats a curtain of falling ceramic Particle to a temperature in excess of 1000 °C. A small scale test platform was built to investigate Particle flow properties. The curtain was comprised of approximately 697 μm ceramic Particles that were dropped within the Receiver cavity of the test platform. Tests were conducted to experimentally determine the distribution of Particles velocity, curtain thickness, and curtain opacity along a drop length of approximately 3 m. Velocity data were measured using a high speed digital camera to obtain images of the Particle flow at 1000 frames per second with an exposure time of 100 μs. Five mass flow rates ranging from 1 kg/s-m to 22 kg/s-m were examined, and it was found that all flows approached a terminal velocity of about 6–7 m/s in a vertical drop distance of 3 m. The experimental results were validated with computational results and were found in excellent agreement with the simulation results. In addition, a similar study was performed with various sizes of the Particles to better understand how the Particle flow characteristics were affected by the size of the Particles.
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central station solar hydrogen power plant
Journal of Solar Energy Engineering-transactions of The Asme, 2007Co-Authors: Gregory J Kolb, Richard Dive, Natha P SiegelAbstract:Solar power towers can be used to make hydrogen on a large scale. Electrolyzers could be used to convert solar electricity produced by the power tower to hydrogen, but this process is relatively inefficient. Rather, efficiency can be much improved if solar heat is directly converted to hydrogen via a thermochemical process. In the research summarized here, the marriage of a high-temperature (∼1000°C) power tower with a sulfuric acid/ hybrid thermochemical cycle was studied. The concept combines a solar power tower, a solid-Particle Receiver, a Particle thermal energy storage system, and a hybrid-sulfuric-acid cycle. The cycle is "hybrid" because it produces hydrogen with a combination of thermal input and an electrolyzer. This solar thermochemical plant is predicted to produce hydrogen at a much lower cost than a solar-electrolyzer plant of similar size. To date, only small lab-scale tests have been conducted to demonstrate the feasibility of a few of the subsystems and a key immediate issue is demonstration of flow stability within the solid-Particle Receiver. The paper describes the systems analysis that led to the favorable economic conclusions and discusses the future development path.
Nathan P Siegel - One of the best experts on this subject based on the ideXlab platform.
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Highlights of the high-temperature falling Particle Receiver project: 2012 - 2016
2017Co-Authors: Joshua M. Christian, Nathan P Siegel, Julius Yellowhair, Sheldon Jeter, Matthew Golob, Clayton Nguyen, Said I. Abdel-khalik, K. Repole, Hany Al-ansaryAbstract:A 1 MWt continuously recirculating falling Particle Receiver has been demonstrated at Sandia National Laboratories. Free-fall and obstructed-flow Receiver designs were tested with Particle mass flow rates of ∼1 – 7 kg/s and average irradiances up to 1,000 suns. Average Particle outlet temperatures exceeded 700 °C for the free-fall tests and reached nearly 800 °C for the obstructed-flow tests, with peak Particle temperatures exceeding 900 °C. High Particle heating rates of ∼50 to 200 °C per meter of illuminated drop length were achieved for the free-fall tests with mass flow rates ranging from 1 – 7 kg/s and for average irradiances up to ∼ 700 kW/m2. Higher temperatures were achieved at the lower Particle mass flow rates due to less shading. The obstructed-flow design yielded Particle heating rates over 300 °C per meter of illuminated drop length for mass flow rates of 1 – 3 kg/s for irradiances up to ∼1,000 kW/m2. The thermal efficiency was determined to be ∼60 – 70% for the free-falling Particle tests an...
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Characterization of Particle Flow in a Free-Falling Solar Particle Receiver
Journal of Solar Energy Engineering, 2016Co-Authors: Joshua M. Christian, Nathan P Siegel, Julius Yellowhair, David Romano, Laura Savoldi, Roberto ZaninoAbstract:Falling Particle Receivers are being evaluated as an alternative to conventional fluid-based solar Receivers to enable higher temperatures and higher efficiency power cycles with direct storage for concentrating solar power (CSP) applications. This paper presents studies of the Particle mass flow rate, velocity, Particle-curtain opacity and density, and other characteristics of free-falling ceramic Particles as a function of different discharge slot apertures. The methods to characterize the Particle flow are described, and results are compared to theoretical and numerical models for unheated conditions. Results showed that the Particle velocities within the first 2 m of release closely match predictions of free-falling Particles without drag due to the significant amount of air entrained within the Particle curtain, which reduced drag. The measured Particle-curtain thickness (∼2 cm) was greater than numerical simulations, likely due to additional convective air currents or Particle–Particle interactions neglected in the model. The measured and predicted Particle volume fraction in the curtain decreased rapidly from a theoretical value of 60% at the release point to less than 10% within 0.5 m of drop distance. Measured Particle-curtain opacities (0.5–1) using a new photographic method that can capture the entire Particle curtain were shown to match well with discrete measurements from a conventional lux meter.
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On-sun testing of an advanced falling Particle Receiver system
2016Co-Authors: Joshua M. Christian, Nathan P Siegel, Julius Yellowhair, Sheldon Jeter, Matthew Golob, Clayton Nguyen, Said I. Abdel-khalik, Hany Al-ansaryAbstract:A 1 MWth high-temperature falling Particle Receiver was constructed and tested at the National Solar Thermal Test Facility at Sandia National Laboratories. The continuously recirculating system included a Particle elevator, top and bottom hoppers, and a cavity Receiver that comprised a staggered array of porous chevron-shaped mesh structures that slowed the Particle flow through the concentrated solar flux. Initial tests were performed with a peak irradiance of ~300 kW/m2 and a Particle mass flow rate of 3.3 kg/s. Peak Particle temperatures reached over 700 °C near the center of the Receiver, but the Particle temperature increase near the sides was lower due to a non-uniform irradiance distribution. At a Particle inlet temperature of ~440 °C, the Particle temperature increase was 27 °C per meter of drop length, and the thermal efficiency was ~60% for an average irradiance of 110 kW/m2. At an average irradiance of 211 kW/m2, the Particle temperature increase was 57.1 °C per meter of drop length, and the th...
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Technology Advancements for Next Generation Falling Particle Receivers
Energy Procedia, 2014Co-Authors: Joshua M. Christian, Nathan P Siegel, Sheldon Jeter, Said I. Abdel-khalik, Hany Al-ansary, Adam C. Moya, David Dennis Gill, Dennis L. Sadowski, Lars AmsbeckAbstract:Abstract The falling Particle Receiver is a technology that can increase the operating temperature of concentrating solar power (CSP) systems, improving efficiency and lowering the costs of energy storage. Unlike conventional Receivers that employ fluid flowing through tubular Receivers, falling Particle Receivers use solid Particles that are heated directly as they fall through a beam of concentrated sunlight for direct heat absorption and storage. Because the solar energy is directly absorbed by the Particles, the flux limitations associated with tubular central Receivers are mitigated. Once heated, the Particles may be stored in an insulated tank and/or used to heat a secondary working fluid (e.g., steam, CO2, air) for the power cycle. Thermal energy storage costs can be significantly reduced by directly storing heat at higher temperatures in a relatively inexpensive, stable medium. This paper presents an overview of recent advancements being pursued in key areas of falling Particle Receiver technology, including (1) advances in Receiver design with consideration of Particle recirculation, air recirculation, and interconnected porous structures; (2) advances in Particle materials to increase the solar absorptance and durability; and (3) advances in the balance of plant for falling Particle Receiver systems including thermal storage, heat exchange, and Particle conveyance.
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CFD Simulation and Performance Analysis of Alternative Designs for High-Temperature Solid Particle Receivers
ASME 2011 5th International Conference on Energy Sustainability Parts A B and C, 2011Co-Authors: Siri S Khalsa, Gregory J Kolb, Nathan P Siegel, Joshua M. Christian, Lars Amsbeck, Marc Röger, Adam C. MoyaAbstract:Direct-absorption solid Particle Receivers are theoretically capable of yielding temperatures in excess of 1000°C, which enables higher efficiency power cycles and lower thermal storage costs. This paper presents rigorous CFD simulations of alternative solid Particle Receiver designs with recirculation to help identify optimal configurations that maximize the Receiver thermal efficiency. The alternative Receiver designs considered are a north-facing cavity Receiver and a face-down surround-field cavity Receiver. The CFD simulations model incident solar radiation from a heliostat field as a boundary condition on the model domain. The CFD simulations also couple convective flow with the thermal and discrete-phase (Particle) solutions, which in turn affects absorption of incident solar radiation and thermal re-radiation within the Receiver. The Receivers are optimized to yield comparable Particle temperatures at the outlets of 750–850°C, heated from an injection temperature of 300°C, and are compared on the basis of thermal efficiency. The CFD simulations yielded thermal efficiencies of the north-facing Receiver at 72.3% (losses were 6.5% radiative and 20.9% convective) and the face-down Receiver at 78.9% (losses were 11.4% radiative and 9.6% convective) at solar noon on March 22. Ongoing efforts are focused on reducing convective and radiative losses from both Receiver configurations.Copyright © 2011 by ASME
Reiner Buck - One of the best experts on this subject based on the ideXlab platform.
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High temperature oxidation and erosion of candidate materials for Particle Receivers of concentrated solar power tower systems
Solar Energy, 2019Co-Authors: Timur Galiullin, Lars Amsbeck, Reiner Buck, Birgit Gobereit, Dmitry Naumenko, M. Neises-von Puttkamer, Willem J. QuadakkersAbstract:Abstract The centrifugal Particle Receiver is a novel concept proposed for concentrated solar power plants (CSP) to increase their operating temperature and efficiency. In this concept solar radiation is directly absorbed by a layer of ceramic Particles held at the inner surface of a rotating cylindrical Receiver by the centrifugal force. During operation, the hot ceramic Particles (up to 1000 °C) move slowly along the Receiver wall as well as other system components (e.g. tubes), which leads to their degradation through high-temperature oxidation and erosion. In the present study, a series of high temperature erosion-oxidation exposures was undertaken to experimentally evaluate performance of selected candidate metallic materials for centrifugal Particle Receivers. The exposures were conducted in a laboratory test facility consisting of a resistance heated furnace filled with ceramic Particles, in which the specimen holder was rotated. Typical high temperature materials, such as martensitic, ferritic and austenitic stainless steels, Ni-base and Co-base alloys were investigated. The specimens were discontinuously exposed at 400–750 °C for up to 500 h and further characterized by scanning electron microscopy (SEM) and energy/wavelength dispersive x-ray spectroscopy (EDX/WDX).
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Operational experience of a centrifugal Particle Receiver prototype
SOLARPACES 2018: International Conference on Concentrating Solar Power and Chemical Energy Systems, 2019Co-Authors: Miriam Ebert, Lars Amsbeck, Jens Rheinländer, Bärbel Schlögl-knothe, Stefan Schmitz, Marcel Sibum, Ralf Uhlig, Reiner BuckAbstract:The centrifugal Particle Receiver “CentRec” is a solar tower Receiver development by DLR based on a direct absorption Receiver concept especially suitable for high temperature process heat and electricity generation applications. Ceramic Particles are used as heat transfer and storage medium for temperatures up to 1000°C. A centrifugal Particle Receiver system including a CentRec Receiver prototype has been tested up to 965°C average Receiver outlet temperature in the research platform of DLR’s test facility Juelich Solar Tower, Germany. This paper describes the first test results with a focus on first operational experiences.
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First On-Sun Tests of a Centrifugal Particle Receiver System
ASME 2018 12th International Conference on Energy Sustainability, 2018Co-Authors: Miriam Ebert, Lars Amsbeck, Jens Rheinländer, Bärbel Schlögl-knothe, Stefan Schmitz, Marcel Sibum, Reiner Buck, Hannes Stadler, Ralf UhligAbstract:One direct absorption Receiver concept currently investigated at the DLR is the Centrifugal Particle Receiver (CentRec®). Successful tests and promising results of this Receiver design have been achieved in a Proof-of-Concept scale with 7.5 kW thermal power and 900°C Particle temperature in 2014. Based on these results the prototype has been scaled up to 2.5 MW thermal power for a future pilot plant. Lab tests have been carried out with infrared heaters. In a next step the prototype has been prepared to be tested on-sun in a test setup in the Juelich Solar Tower, Germany. The tests aim to demonstrate high temperature operation and to evaluate the performance of the system. The test setup consists of a centrifugal Receiver integrated into the tower and a closed loop Particle transport system. The transport system includes an air cooling system to cool down the Particles at the Receiver outlet, cold Particle storage, belt bucket elevator, hopper and Particle metering system. While the 2.5 MWth Receiver prototype has been developed in a former project, the further infrastructure for the on-sun tests needed to be designed, manufactured and installed. The system is equipped with measurement instrumentation, data acquisition system and control software. Manufacturing of all main components has been completed. Installation of the test setup started in November 2016 and finished in June 2017. Cold and hot commissioning have been carried out from July 2017 until September 2017. On-sun tests started in September 2017. Receiver tests up to 775°C/1,430°F Receiver outlet temperature and more than 900°C/1,650°F Particle temperature in the Receiver have already been achieved. Tests up to 900°C Particle outlet temperature are planned at different load levels and will be conducted until summer 2018. This paper describes the test setup for a centrifugal Particle Receiver system, presenting design, installation and commissioning of the system. It presents test results of first on-sun tests and gives an outlook on further steps regarding solar tests planned for 2018.
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First tests of a centrifugal Particle Receiver with a 1m2 aperture
2018Co-Authors: Lars Amsbeck, Miriam Ebert, Jens Rheinländer, Reiner Buck, Birgit Gobereit, Johannes Hertel, Andrea Jensch, David Trebing, Ralf UhligAbstract:Particle Receivers achieve significantly higher temperatures than state of the art molten salt solar towers. The centrifugal Particle Receiver is a direct absorption Receiver with a simple control of the residence time of the Particles in the Receiver. The paper describes the cold testing including mechanics of the Particle film and first hot testing using a 100 kWel infrared heater.Particle Receivers achieve significantly higher temperatures than state of the art molten salt solar towers. The centrifugal Particle Receiver is a direct absorption Receiver with a simple control of the residence time of the Particles in the Receiver. The paper describes the cold testing including mechanics of the Particle film and first hot testing using a 100 kWel infrared heater.
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upscaling manufacturing and test of a centrifugal Particle Receiver
International Conference on Fuel Cell Science Engineering and Technology FUELCELL Collocated with ASME International Conference on Energy Sustainabili, 2016Co-Authors: Miriam Ebert, Lars Amsbeck, Jens Rheinländer, Ralf Uhlig, Johannes Hertel, Andrea Jensch, David Trebing, Reiner BuckAbstract:Previous successful tests and promising results of a Centrifugal Particle Receiver (CentRec) for high temperature solar applications has been achieved in a lab scale prototype with 7.5 kWth [1, 2, 3]. In a next step this Receiver technology is scaled up to higher thermal power for a future pilot plant. This paper presents the optimization methodology of the design and technical solutions. It describes the manufacturing and assembly of the prototype and first tests and results of the commissioning including cold Particle tests and prototype costs. Finally the paper gives an outlook on the planned further steps regarding hot lab tests and solar tests.
Lars Amsbeck - One of the best experts on this subject based on the ideXlab platform.
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Operational experience of a centrifugal Particle Receiver prototype
SOLARPACES 2018: International Conference on Concentrating Solar Power and Chemical Energy Systems, 2019Co-Authors: Miriam Ebert, Lars Amsbeck, Jens Rheinländer, Bärbel Schlögl-knothe, Stefan Schmitz, Marcel Sibum, Ralf Uhlig, Reiner BuckAbstract:The centrifugal Particle Receiver “CentRec” is a solar tower Receiver development by DLR based on a direct absorption Receiver concept especially suitable for high temperature process heat and electricity generation applications. Ceramic Particles are used as heat transfer and storage medium for temperatures up to 1000°C. A centrifugal Particle Receiver system including a CentRec Receiver prototype has been tested up to 965°C average Receiver outlet temperature in the research platform of DLR’s test facility Juelich Solar Tower, Germany. This paper describes the first test results with a focus on first operational experiences.
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High temperature oxidation and erosion of candidate materials for Particle Receivers of concentrated solar power tower systems
Solar Energy, 2019Co-Authors: Timur Galiullin, Lars Amsbeck, Reiner Buck, Birgit Gobereit, Dmitry Naumenko, M. Neises-von Puttkamer, Willem J. QuadakkersAbstract:Abstract The centrifugal Particle Receiver is a novel concept proposed for concentrated solar power plants (CSP) to increase their operating temperature and efficiency. In this concept solar radiation is directly absorbed by a layer of ceramic Particles held at the inner surface of a rotating cylindrical Receiver by the centrifugal force. During operation, the hot ceramic Particles (up to 1000 °C) move slowly along the Receiver wall as well as other system components (e.g. tubes), which leads to their degradation through high-temperature oxidation and erosion. In the present study, a series of high temperature erosion-oxidation exposures was undertaken to experimentally evaluate performance of selected candidate metallic materials for centrifugal Particle Receivers. The exposures were conducted in a laboratory test facility consisting of a resistance heated furnace filled with ceramic Particles, in which the specimen holder was rotated. Typical high temperature materials, such as martensitic, ferritic and austenitic stainless steels, Ni-base and Co-base alloys were investigated. The specimens were discontinuously exposed at 400–750 °C for up to 500 h and further characterized by scanning electron microscopy (SEM) and energy/wavelength dispersive x-ray spectroscopy (EDX/WDX).
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First On-Sun Tests of a Centrifugal Particle Receiver System
ASME 2018 12th International Conference on Energy Sustainability, 2018Co-Authors: Miriam Ebert, Lars Amsbeck, Jens Rheinländer, Bärbel Schlögl-knothe, Stefan Schmitz, Marcel Sibum, Reiner Buck, Hannes Stadler, Ralf UhligAbstract:One direct absorption Receiver concept currently investigated at the DLR is the Centrifugal Particle Receiver (CentRec®). Successful tests and promising results of this Receiver design have been achieved in a Proof-of-Concept scale with 7.5 kW thermal power and 900°C Particle temperature in 2014. Based on these results the prototype has been scaled up to 2.5 MW thermal power for a future pilot plant. Lab tests have been carried out with infrared heaters. In a next step the prototype has been prepared to be tested on-sun in a test setup in the Juelich Solar Tower, Germany. The tests aim to demonstrate high temperature operation and to evaluate the performance of the system. The test setup consists of a centrifugal Receiver integrated into the tower and a closed loop Particle transport system. The transport system includes an air cooling system to cool down the Particles at the Receiver outlet, cold Particle storage, belt bucket elevator, hopper and Particle metering system. While the 2.5 MWth Receiver prototype has been developed in a former project, the further infrastructure for the on-sun tests needed to be designed, manufactured and installed. The system is equipped with measurement instrumentation, data acquisition system and control software. Manufacturing of all main components has been completed. Installation of the test setup started in November 2016 and finished in June 2017. Cold and hot commissioning have been carried out from July 2017 until September 2017. On-sun tests started in September 2017. Receiver tests up to 775°C/1,430°F Receiver outlet temperature and more than 900°C/1,650°F Particle temperature in the Receiver have already been achieved. Tests up to 900°C Particle outlet temperature are planned at different load levels and will be conducted until summer 2018. This paper describes the test setup for a centrifugal Particle Receiver system, presenting design, installation and commissioning of the system. It presents test results of first on-sun tests and gives an outlook on further steps regarding solar tests planned for 2018.
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First tests of a centrifugal Particle Receiver with a 1m2 aperture
2018Co-Authors: Lars Amsbeck, Miriam Ebert, Jens Rheinländer, Reiner Buck, Birgit Gobereit, Johannes Hertel, Andrea Jensch, David Trebing, Ralf UhligAbstract:Particle Receivers achieve significantly higher temperatures than state of the art molten salt solar towers. The centrifugal Particle Receiver is a direct absorption Receiver with a simple control of the residence time of the Particles in the Receiver. The paper describes the cold testing including mechanics of the Particle film and first hot testing using a 100 kWel infrared heater.Particle Receivers achieve significantly higher temperatures than state of the art molten salt solar towers. The centrifugal Particle Receiver is a direct absorption Receiver with a simple control of the residence time of the Particles in the Receiver. The paper describes the cold testing including mechanics of the Particle film and first hot testing using a 100 kWel infrared heater.
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upscaling manufacturing and test of a centrifugal Particle Receiver
International Conference on Fuel Cell Science Engineering and Technology FUELCELL Collocated with ASME International Conference on Energy Sustainabili, 2016Co-Authors: Miriam Ebert, Lars Amsbeck, Jens Rheinländer, Ralf Uhlig, Johannes Hertel, Andrea Jensch, David Trebing, Reiner BuckAbstract:Previous successful tests and promising results of a Centrifugal Particle Receiver (CentRec) for high temperature solar applications has been achieved in a lab scale prototype with 7.5 kWth [1, 2, 3]. In a next step this Receiver technology is scaled up to higher thermal power for a future pilot plant. This paper presents the optimization methodology of the design and technical solutions. It describes the manufacturing and assembly of the prototype and first tests and results of the commissioning including cold Particle tests and prototype costs. Finally the paper gives an outlook on the planned further steps regarding hot lab tests and solar tests.