Computational modeling and on-sun model validation for a multiple tube solar reactor with specularly reflective cavity walls. Part 1: Heat transfer model

Martinek, Janna; Bingham, Carl; Weimer, Alan W.

doi:10.1016/j.ces.2012.06.064

Cited by 28 publications

(21 citation statements)

References 29 publications

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“…Particles are generally considered or approximated as spherical which allows for the use of an exact solution to the electrodynamic scattering problem for a sphere, the Lorenz-Mie solution, to get the necessary RTE parameters. This approach is found widely in the literature for the dilute fluidised case (Haussener et al, 2009;Martinek et al, 2012a;Martinek and Weimer, 2013a;Z'Graggen and Steinfeld, 2009). Jäger et al uses a slightly modified Lorenz-Mie prediction to better fit experimental results (Jäger et al, 2009).…”

Section: Radiative Energy Transfermentioning

confidence: 99%

“…Solar radiative heat flux (a) and temperature (b) on the perimeter of the reaction tubes at the horizontal centre plane of the reactor at 6 kW solar power input to the reactor. Reproduced with permission from (Martinek et al, 2012a). Fig.…”

Section: Example 2: Directly Irradiated Porous Ceria Redox Systemmentioning

confidence: 99%

“…Relevant STRS studies using this approach include (Haussener et al, 2009;Martinek et al, 2012a;Martinek and Weimer, 2013a;Saade et al, 2012;Z'Graggen and Steinfeld, 2009). When the particles Stokes number is not so small to warrant the entrainment approximation, the interactions between the fluid and particle need to be resolved.…”

Section: Momentum Transfermentioning

confidence: 99%

“…It was found that a hybrid MC/FV approach, that took the accuracy of the MC method with the easy compatibility of the FV with CFD solvers, was an ''optimal" approach. Further studies from the Colorado group have used this hybrid method (Groehn et al, 2016;Martinek et al, 2012a). The DO is a discretisation approach that relies on replacing the specific intensity, which is continuous in propagation direction, with a finite number of specific intensities evaluated at certain propagation directions (abscissa), thus forming a quadrature for properties calculated by integrals over direction-internal energy density, heat flux, etc.…”

Section: Radiative Energy Transfermentioning

confidence: 99%

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Modelling of solar thermochemical reaction systems

et al. 2017

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a b s t r a c tThis article reviews the progress, challenges and opportunities in numerical modelling of thermal transport, thermochemical reactions and thermomechanics in high-temperature solar thermochemical systems. Continuum-scale models are presented in mathematical detail while highlighting the literature that uses them. The discussion is enhanced by selected examples of numerical studies of solar thermochemical systems for solar fuels and commodity material production. Property predictions necessary for the modelling of solar thermochemical reaction systems are covered.

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Section: Radiative Energy Transfermentioning

confidence: 99%

Section: Example 2: Directly Irradiated Porous Ceria Redox Systemmentioning

confidence: 99%

Section: Momentum Transfermentioning

confidence: 99%

Section: Radiative Energy Transfermentioning

confidence: 99%

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Modelling of solar thermochemical reaction systems

et al. 2017

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“…The solar receiver is a key component in these applications converting solar energy efficiently into thermal energy. Numerical models offer an effective pathway for the characterization and quantification of the optical, thermal, and fluid flow behavior of receivers [12][13][14][15][16][17][18]. When steam is used as the working fluid (CSP application) or as the reactant in high-temperature systems (STEP and SHTE applications), the understanding of the complex two-phase flow boiling process inside the absorber tubes of the direct steam generation receiver is important for identifying local hot spots, and designing and predicting receiver performance.…”

Section: Introductionmentioning

confidence: 99%

Modeling and design guidelines for direct steam generation solar receivers

et al. 2018

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• A computational model for solar receiver for direct steam generation is developed.• Experiments are conducted and used to validate the model.• Practical designs, operational conditions and material choices are investigated.• Model provides design tool for direct steam generation solar cavity receivers. A R T I C L E I N F OKeyword: Solar energy Multi-mode heat transfer modeling Two-phase flow modeling Solar receiver Steam generator Concentrated solar A B S T R A C T Concentrated solar energy is an ideal energy source for high-temperature energy conversion processes such as concentrated solar power generation, solar thermochemical fuel production, and solar driven high-temperature electrolysis. Indirectly irradiated solar receiver designs utilizing tubular absorbers enclosed by a cavity are possible candidates for direct steam generation, allowing for design flexibility and high efficiency. We developed a coupled heat and mass transfer model of cavity receivers with tubular absorbers to guide the design of solardriven direct steam generation. The numerical model consisted of a detailed 1D two-phase flow model of the absorber tubes coupled to a 3D heat transfer model of the cavity receiver. The absorber tube model simulated the flow boiling phenomena inside the tubes by solving 1D continuity, momentum, and energy conservation equations based on a control volume formulation. The Thome-El Hajal flow pattern maps were used to predict liquid-gas distributions in the tubular cross-sections, and heat transfer coefficients and pressure drop along the tubes. The heat transfer coefficient and fluid temperature of the absorber tubes' inner surfaces were then extrapolated to the circumferential of the tube and used in the 3D cavity receiver model. The 3D steady state model of the cavity receiver coupled radiative, convective, and conductive heat transfer. The complete model was validated with experimental data and used to analyze different receiver types and designs made of different materials and exposed to various operational conditions. The proposed numerical model and the obtained results provide an engineering design tool for cavity receivers with tubular absorbers (in terms of tube shapes, tube diameter, and water-cooled front), support the choice of best-performant operation (in terms of radiative flux, mass flow rate, and pressure), and aid in the choice of the component materials. The model allows for an indepth understanding of the coupled heat and mass transfer in the solar receiver for direct steam generation and can be exploited to quantify the optimization potential of such solar receivers.

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