학술논문

A Numerical Case Study of Particle Flow and Solar Radiation Transfer in a Compound Parabolic Concentrator (CPC) Photocatalytic Reactor for Hydrogen Production.
Document Type
Article
Source
Catalysts (2073-4344). Apr2024, Vol. 14 Issue 4, p237. 19p.
Subject
*COMPOUND parabolic concentrators
*GRANULAR flow
*SOLAR radiation
*SOLAR ultraviolet radiation
*HYDROGEN production
*RADIATIVE transfer equation
SOLAR chimneys
Language
ISSN
2073-4344
Abstract
Highlights: What are the main findings? A comprehensive simulation model including particle flow and radiation transfer was developed for a CPC photocatalytic reactor. The ray tracing method was utilized to determine the radiation reaching the surface of the receiving tube, while the discrete ordinates method (DOM) was also employed to solve the radiative transfer equation (RTE), which shows the complete process of solar energy transfer. What is the implication of the main finding? Local volume radiative power absorption (LVRPA) and total radiative power absorption (TRPA) inside the receiving tube was obtained by this study, which is critical data for the photocatalytic reactor. Natural convection with intermittent disturbances is demonstrated to be effective operating mode for the CPC photocatalytic reactor. Compound parabolic concentrator (CPC) photocatalytic reactors are commonly used for photocatalytic water splitting in hydrogen production. This study aimed to gain a better understanding of the physical processes in CPC photocatalytic reactors and provide theoretical support for their design, optimization, and operation. The analysis involved the ray tracing approach, Euler–Euler two-fluid model, and discrete ordinates method (DOM) to study solar radiation transfer and particle flow in the reactor. The distribution of solar radiation on the receiving tube's surface after CPC concentration was obtained by conducting the ray tracing approach. This solar radiation distribution was then coupled into the Euler–Euler two-fluid model to solve for the natural convection flow field, the temperature field, and particle phase volume fraction distribution inside the receiving tube over a period of 120 s. Lastly, the discrete ordinates method (DOM) was used to analyze the transfer of radiation inside the receiving tube at different times, obtaining the distribution of local volume radiative power absorption (LVRPA) and the total radiative power absorption (TRPA) inside the tube. The results showed that the TRPA reached its maximum at 120 s, accounting for 66.61% of the incident solar UV radiation. According to the above results, it could be suggested that adopting an intermittent operation mode in CPC photocatalytic reactors is reasonable and efficient. [ABSTRACT FROM AUTHOR]