Collector Efficiency in Downward-Type Internal-Recycle Solar Air Heaters with Attached Fins

Energies

Ho-Ming Yeh¹ 

[1] Energy and Opto-Electronic Materials Research Center, Department of Chemical and Materials Engineering, Tamkang University, Tamsui, New Taipei 251, Taiwan; E-Mail

关键词: collector efficiency;    solar air heater;    downward type;    fins attached;    flat plate;    internal recycle;   

DOI  :  10.3390/en6105130

来源: mdpi

【 摘 要 】

The internal-recycle operation effect on collector efficiency in downward-type rectangular solar air heaters with attached fins is theoretically investigated. It is found that considerable collector efficiency is obtainable if the collector has attached fins and the operation is carried out with internal recycling. The recycling operation increases the fluid velocity to decrease the heat transfer resistance, compensating for the undesirable effect of decreasing the heat transfer driving force (temperature difference) due to remixing. The attached fins provide an enlarged heat transfer area. The order of performance in a device of same size is: double pass with recycle and fins > double pass with recycle but without fins > single pass without recycle and fins.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.