Abstract

An experimental investigation of thermohydraulic performance characteristics of a packed bed solar air heater is done in the present work. The packed bed is generally used to enhance the heat transfer area, increase the turbulence in the flow and for the storage of thermal energy. The experimental investigation has been carried out on a low porosity packed bed solar air heater. The investigation covers a particular range of design and operating parameters. Design parameters take account of the equivalent diameter of packing material (1.55 mm), packing density (250 g per 0.075 m³) and colour of the packed bed material (Black) while the operating parameters take account of the mass flow rate ranging from 0.01 to 0.04 kg/s. It is observed that the efficiency of the air heater increases with increase in mass flow rate. It is also found that the impact on the overall efficiency due to frictional loss is much less in a low porosity packed bed solar air heater.

中文翻译：

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检查填充床太阳能空气加热器整体性能的实验研究

摘要

在目前的工作中进行了填充床太阳能空气加热器的热工水力特性的实验研究。填充床通常用于增加传热面积，增加气流湍流并用于存储热能。实验研究是在低孔隙率填充床太阳能空气加热器上进行的。调查涵盖特定范围的设计和操作参数。设计参数考虑了填料的等效直径（1.55 mm），填料密度（每0.075 m ³ 250 g））和填充床材料的颜色（黑色），而运行参数则考虑了0.01至0.04 kg / s的质量流率。观察到空气加热器的效率随着质量流量的增加而增加。还发现在低孔隙率填充床太阳能空气加热器中，由于摩擦损失而对整体效率的影响要小得多。