泡沫填充方式对管内超临界CO2流动换热的影响研究

超临界CO₂工质在太阳能热发电系统中的应用能够有效提升整个系统的效率、紧凑性和环境友好性，因此有必要优化超临界CO₂用太阳能集热器的综合性能。提出了泡沫材料有效热导率新的预测模型，并研究了不同泡沫材料填充方式对集热管内超临界CO₂流动与换热性能、管壁温度分布的影响规律。结果表明，环形填充方式（沿管内壁填充）的流动换热综合性能指标(j/j _c)/(f/f _c)^1/3最优，净吸热量最大，管壁最高温度最低且温度分布最均匀。

Research on effects of foam filling types on heat transfer of supercritical CO2 flow in tube

The application of supercritical CO₂ in solar thermal power generation system could effectively improve the efficiency, compactness and environmental friendly of the system. Therefore, it is necessary to optimize the comprehensive performance of solar collectors using supercritical CO₂. In this paper, a new calculation model for the effective thermal conductivity of foam materials is proposed. The effects of different foam filling types on the flow and heat transfer performance and wall temperature distribution in receiver tubes are studied. The results show that the flow-heat transfer performance index (j/j _c)/(f/f _c)^1/3 is optimal for the annular filling method (filled along the inner wall of the tube), the net heat absorption is the largest, the highest wall temperature is the lowest and the temperature distribution is the same.