Solid particles can be used as a heat transfer medium in concentrated solar power plants to operate at higher temperature and achieve higher heat conversion efficiency than using the current solar heat transfer fluids that only work below 600°C. Among various particle circulation concepts, the dense particle suspension (DPS) flow in tubes, also called upflow bubbling fluidized bed (UBFB), was studied in the frame of the CSP2 FP7 European project. The DPS capacity to extract heat from a tube absorber exposed to concentrated solar radiation was demonstrated and the first values of the tube wall‐to‐DPS heat transfer coefficient were measured. A stable outlet temperature of 750°C was reached with a metallic tube, and a particle reflux in the near tube wall region was evidenced. In this article, the UBFB behavior is studied using the multiphase flow code NEPTUNE_CFD. Hydrodynamics of SiC Geldart A‐type particles and heat transfer imposed by a thermal flux at the wall are coupled in two‐dimensional unsteady numerical simulations. The convective/diffusive heat transfer between the gas and dispersed phase, and the inter‐particle radiative transfer (Rosseland approximation) are accounted for. Simulations and experiments are compared here and the temperature influence on the DPS flow is analyzed. © 2018 American Institute of Chemical Engineers AIChE J, 64: 3857–3867, 2018

中文翻译：

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高通量太阳加热下不透明管内上升流鼓泡流化床的三维数值模拟

固体颗粒可用作集中式太阳能发电厂中的传热介质，与使用目前仅在600°C以下工作的太阳能传热流体相比，可以在更高的温度下运行并实现更高的热转换效率。在各种颗粒循环概念中，在CSP2 FP7欧洲项目的框架内研究了管中的稠密颗粒悬浮液（DPS），也称为上流鼓泡流化床（UBFB）。展示了DPS从暴露于集中太阳辐射的管式吸收器中提取热量的能力，并测量了管壁到DPS的传热系数的第一个值。用金属管达到稳定的出口温度为750°C，并且在近管壁区域发现了颗粒回流。在本文中，使用多相流代码NEPTUNE_CFD研究UBFB行为。二维非定常数值模拟将SiC Geldart A型颗粒的流体动力学和壁上的热通量施加的热传递耦合在一起。考虑了气相和分散相之间的对流/扩散传热以及粒子间的辐射传递（Rosseland近似）。在此对仿真和实验进行了比较，并分析了温度对DPS流量的影响。©2018美国化学工程师学会 并考虑了粒子间辐射传递（Rosseland近似）。在此比较了仿真和实验，并分析了温度对DPS流量的影响。©2018美国化学工程师学会 并考虑了粒子间辐射传递（Rosseland近似）。在此对仿真和实验进行了比较，并分析了温度对DPS流量的影响。©2018美国化学工程师学会AIChE J，64：3857–3867，2018