Plate Temperature and Heat Transfer Characteristics of Artificially Roughened Solar Air Heater

B.N. Prasad, G.N. Sah
2014 Energy Procedia  
Higher value of intensity of radiation on absorber plate of solar air heaters and effective heat removal from the plate by the carrier fluid, air, enhances thermal performance of solar air heaters. The paper deals with the experimental results of enhancing the intensity of radiation by means of booster mirrors and that of heat transfer by means of providing artificial roughness on the air flow side of the absorber plate. An enhancement in radiation of about 40% have been found over the normal
more » ... cident radiation by means of booster mirrors leading to higher rate of heat collection. The thermal performance parameters F R and F ' have been found to increase in the range of 90% to 130% and 92% to 135% respectively in comparison to those of smooth solar air heaters without booster mirrors and in the range of 10% to 15% in comparison to roughened solar air heater without booster mirrors for the same pressure drop due to artificial roughness within the range of the parameters investigated. Keyword: Plate temperature; Booster mirror; Relative roughness pitch (p/ε); relative roughness height (ε/D); collector heat removal factor (F R ); plate efficiency factor (F ' ).
doi:10.1016/j.egypro.2014.12.387 fatcat:xjat3sdlgne6rdp6o6f7i5h6su