High-temperature optical and radiative properties of alumina–silica-based ceramic materials for solar thermal applications
- Authors: Chen, Jingling , Torres, Juan , Hosseini, Sahar , Kumar, Apurv , Coventry, Joe , Lipiński, Wojciech
- Date: 2022
- Type: Text , Journal article
- Relation: Solar Energy Materials and Solar Cells Vol. 242, no. (2022), p.
- Full Text: false
- Reviewed:
- Description: Optical and radiative properties of alumina–silica-based ceramic materials are determined in the spectral range of 3–10
Radiation analysis of a particle curtain using polydisperse particel size eulerian granular CFD modelling
- Authors: Patel, Smitkumar , Chen, Jingling , Coventry, Joe , Lipinski, Wojciech , Kumar, Apurv
- Date: 2022
- Type: Text , Conference paper
- Relation: 7th Thermal and Fluids Engineering Conference, TFEC 2022, Las Vegas USA, 15-18 May 2022, Proceedings of the Thermal and Fluids Engineering Summer Conference Vol. 2022-May, p. 969-981
- Full Text: false
- Reviewed:
- Description: A solid particle receiver is a principal element in concentrated solar power technology in which falling ceramic particles in a cavity are exposed to extremely concentrated solar irradiation. Such particle receiver holds great promise in achieving high thermal efficiencies due to the possibility of reaching temperatures as high as 1000° C. To accurately model the hydrodynamics and the radiation heat transfer, it is imperative to simulate particle-gas interactions more realistically. All the particle receiver modelling till date has used only monodisperse size assumption to simplify the simulation. However, the radiation interaction with the particle curtain is greatly dependent on the size-dependent radiation properties. In the present work, we aim to model the two-dimensional mass, momentum and radiative transfer equations using a Eulerian-Eulerian multiphase granular model and the discrete ordinates model with a particle size distribution in the falling particles. Gaussian distribution is assumed as a representative size distribution spread around a mean particle size of magnitudes generally used in particle receivers (~100-500 µm). The distribution is then split into n size bands and the Eulerian granular flow is modelled for n secondary phases (up to 3 in this study) with a corresponding concentration to simulate the particle size distribution. Each particle size band was prescribed unique size dependent radiation absorption and scattering coefficient for solving the discrete ordinates radiative transfer equation. Finally, a parametric study is carried out to understand the effect of different particle sizes and their concentration on the volume fraction distribution, particle velocities and radiation absorption by the curtain inside the receiver. © 2022 Begell House Inc.. All rights reserved.
Heat transfer in directly-irradiated high-temperature solid–gas flows laden with polydisperse particles
- Authors: Chen, Jingling , Kumar, Apurv , Coventry, Joe , Lipiński, Wojciech
- Date: 2022
- Type: Text , Journal article
- Relation: Applied Mathematical Modelling Vol. 110, no. (2022), p. 698-722
- Full Text: false
- Reviewed:
- Description: Heat transfer in directly-irradiated high-temperature solid–gas flows laden with polydisperse particles is investigated using a novel transient three-dimensional computational fluid dynamics model. The model couples particle–gas hydrodynamics of solid–gas flows laden with polydisperse particles, radiative heat transfer in non-grey absorbing, emitting and anisotropically-scattering multi-component participating media, conduction heat transfer in the gas phase, and interfacial convection heat transfer. The multiphase particle-in-cell method is used to predict high-fidelity solid–gas flow characteristics, such as the local discrete particle size distribution, with increased computational efficiency by combining the advantages of both Eulerian and Lagrangian methods. The multi-component radiative transfer model is implemented using an advanced collision-based Monte Carlo ray-tracing method. The number of the prescribed discrete particle components is found to be the key parameter affecting the computational accuracy and efficiency, which primarily depends on the size distribution of the particles. For the model particle–gas flow featuring free-falling Gamma-distributed ceramic particles exposed to concentrated solar irradiation, the particle volume fraction, radiative, fluid flow and thermal characteristics appear to converge with the increasing number of the discrete particle components. Five particle components are sufficient to obtain physically meaningful results. A further increase in the number of the particle components only slightly increases the accuracy of the numerical predictions at the expense of a rapidly increasing computational time. For five particle components, the particle vertical velocity at the receiver exit for particles with the diameter of 43.4
Radiative heat transfer in solar particle receivers
- Authors: Chen, Jingling , Kumar, Apurv , Coventry, Joe , Lipiński, Wojciech
- Date: 2023
- Type: Text , Conference paper
- Relation: 10th International Symposium on Radiative Transfer, RAD 2023, Thessaloniki, Greece, 12-16 June 2023, Proceedings of the 10th International Symposium on Radiative Transfer Vol. 2023-June, p. 291-298
- Full Text: false
- Reviewed:
- Description: Energy flow and conversion in high-temperature solar particle receivers are investigated by theoretical, numerical, and experimental approaches. Alumina–silica-based ceramic particle materials are synthesised, and optically and radiatively characterised. Advanced numerical models of particle–gas two-phase flows under direct high-flux solar irradiation are developed to understand the flow physics, predict receiver thermal characteristics, and enable receiver technology advancement. © 2023 Proceedings of the International Symposium on Radiative Transfer.