A new numerical method for determining heat transfer and packing distribution in particle heat exchangers for concentrated solar power

摘要

The complex nature of the physics of solid-gas interactions in concentrated solar particle heat exchangers signifies the need to develop new and cutting-edge numerical models to understand these interactions with the overarching goal of optimizing industrial solar thermal processes. To this end, a coupled computational fluid dynamics and discrete element method is developed to unravel near-wall particle flow physics of solar industrial heat exchangers. In addition, advanced post-processing functions are developed to provide a high-end data visualization and quantitative assessment of the packing distribution of solar particle heat exchangers. The validated numerical model shows that the particle temperature varies considerably throughout the entire fluid filled packed particle bed and it is shown that thermal radiation contribution becomes more profound at higher operating temperatures, namely 1073-1173 K. Also, the temperatures and solid volume fractions of the near-wall particles differ greatly compared to the bulk particles. The methods presented herein can be implemented by engineers and scientists to evaluate near-wall packing distributions and thermal characteristics, which would be useful for optimizing the geometric morphology of solar industrial heat exchangers.