Optimal process of solar to thermal energy conversion and design of irreversible flat-plate solar collectors

• Published in: Energy (Oxford) Vol. 28; no. 2; pp. 99 - 113
• Main Authors: Torres-Reyes, E, Navarrete-González, J.J, Zaleta-Aguilar, A, Cervantes-de Gortari, J.G
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.02.2003; Elsevier Science
• Subjects: Applied sciences; Energy; Exact sciences and technology; Natural energy; Solar collectors; Solar energy; Solar thermal conversion; Solar collector; Exergy analysis; Energy conversion; Irreversible process; Second law of thermodynamics; Flat plate collectors; Performance; Optimization; Heat transfer
• ISSN: 0360-5442
• DOI: 10.1016/S0360-5442(02)00095-6

Thermodynamic optimization based on the first and the second law is developed to determine the optimal performance parameters and to design a solar to thermal energy conversion system. An exergy analysis is presented to determine the optimum outlet temperature of the working fluid and the optimum path flow length of solar collectors with various configurations. The collectors used to heat the air flow during solar-to-thermal energy conversion, are internally arranged in different ways with respect to the absorber plates and heat transfer elements. The exergy balance and the dimensionless exergy relationships are derived by taking into account the irreversibilities produced by the pressure drop in the flow of the working fluid through the collector. Design formulas for different air duct and absorber plate arrangements are obtained.