Abstract To perform thermochemical cycles using non-volatile metal oxides to split water and produce hydrogen, a directly irradiated fluidized bed reactor is designed and fabricated for beam-down configuration. As the main aim of this investigation is to analyze the heat transfer and particulate flow of the reactor, chemically inert particles are used. A transient 3D heat and mass transfer model is formulated by the combined approach of discrete element method and computational fluid dynamics. The radiative transfer is solved using the discrete ordinate radiation model. Experimental validation is accomplished by the measured temperatures, obtained with the fluidized bed reactor prototype tested under 30 kWth high-flux solar simulator. The model is applied to analyze the granular flow characteristics and efficiency of the reactor for various superficial gas velocities and bed masses. The results indicate that higher gas flow rate increases the velocity and convection loss of the bed and decreases the bed temperature and efficiency of the reactor.

中文翻译：

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用于热化学循环的 30 kW 直接辐照太阳能流化床反应器的传热和颗粒流分析

摘要 为了利用非挥发性金属氧化物进行热化学循环以分解水并产生氢气，设计并制造了直射式流化床反应器，用于束下配置。由于本研究的主要目的是分析反应器的传热和颗粒流，因此使用了化学惰性颗粒。瞬态 3D 传热传质模型是通过离散元方法和计算流体动力学的组合方法制定的。辐射传输使用离散纵坐标辐射模型求解。通过在 30 kWth 高通量太阳能模拟器下测试流化床反应器原型获得的测量温度完成实验验证。该模型用于分析各种表观气体速度和床层质量下反应器的颗粒流动特性和效率。结果表明，较高的气体流速增加了床层的速度和对流损失，并降低了床层温度和反应器的效率。