Abstract:

A cavity-shaped porous solar receiver (CPSR) with a cavity at the inlet section was proposed to solve the mismatch between the mass velocity of the heat transfer fluid (HTF) and the distribution of concentrated solar flux (CSF), as well as the issues of high solid peak temperature and significant infrared radiation losses. Based on a coupled heat transfer model and validation through a small-scale solar simulator, the influence of cavity shape and geometric dimensions on optimization objectives (thermal efficiency and solid peak temperature) was analyzed using orthogonal optimization. The results indicated that the divergent cavity-shaped receiver exhibited higher thermal efficiency compared to the convergent and cylindrical cavity designs. The opening radius had the most significant effect on thermal efficiency, while the depth was the key factor determining the solid peak temperature. Comprehensive range and variance analyses revealed that the optimal geometric dimensioned for the CPSR. At the standard mass flow rate of 5g/s, the solid peak temperature of the optimal CPSR decreased by 488K compared to the solid porous solar receiver (SPSR), while the thermal efficiency increased by approximately 21.48%. The findings provide a valuable reference for improving the heat transfer performance of PSR.

Key words: solar energy, solar receiver, porous media, thermal performance, thermal efficiency

摘要：

为解决多孔介质吸热器质量流速与聚集太阳能流密度不匹配、固体峰值温度高及红外辐射损失大的问题，本文提出了一种凹腔多孔介质吸热器模型，建立了凹腔多孔介质吸热器耦合传热模型，并进行了验证。在此基础上，以热效率和固体峰值温度为优化目标，采用正交优化法分析凹腔形状和几何尺寸对优化目标的影响规律。结果表明，渐扩型凹腔吸热器的热效率高于渐缩型和圆柱型，且开口半径对热效率影响最显著，凹腔深度是决定固体峰值温度的关键因素。通过极差和方差综合分析得到凹腔吸热芯的最佳几何尺寸。在质量流率{\dot{m}}_{\mathrm{f}}=5g/s的标准工况下，与实心多孔介质吸热器相比，最佳凹腔多孔介质吸热器的固体峰值温度较前者降低488K，热效率提升了约21百分点。本文研究结果为多孔介质吸热器综合性能优化和技术创新提供参考依据。

关键词: 太阳能, 吸热器, 多孔介质, 传热性能, 热效率