Thermal performance of a solar box cooker with outer reflectors: Numerical study and experimental investigation. (December 2017)

• Record Type: Journal Article
• Authors: Guidara, Zied; Souissi, Mahmoud; Morgenstern, Alexander; Maalej, Aref
• Is Part Of: Solar energy. Volume 158(2017)
• Page Start: 347
• Page End: 359
• Publication Date: 2017-12
• Subjects: Box-type solar cooker design -- Outer reflectors -- Thermal balances -- Computer simulation -- Experimental results -- Thermal performance improvement; Solar energy -- Periodicals; Solar engines -- Periodicals; 621.47
• DOI: 10.1016/j.solener.2017.09.054
• Languages: English
• ISSNs: 0038-092X

Abstract

Highlights: Outer reflectors have a great impact on the performance of the solar cooker. A high absorber plate temperature was achieved under normal ambient conditions. A boiling time of one hour was achieved during a stagnation test. A mathematical model gave accurate results when comparing theory and experiments. Abstract: A design of a box-type solar cooker was modeled and tested in the region of Sfax-Tunisia. This solar cooker was designed to allow reaching relatively high temperatures during days with low solar radiation owing to four outer reflectors. A mathematical model, which is based on thermal balances, was developed and implemented in a Matlab program to predict the thermal performances of the solar cooker. Several tests were effectuated in order to validate the robustness of the mathematical model and to determine the thermal performance of the solar cooker. The obtained results showed an acceptable matching between the experimental temperature values and the computed temperature values with a maximum error inferior to 4%. It was also proven that the use of four outer reflectors improved the optical efficiency of the solar cooker. Indeed, the first figure of merit passed from 0.07 to 0.14 and the maximum temperature of the absorber plate passed from 81.3 °C to 133.6 °C. The sensible loading test revealed that the calculated second figures of merit for different water loads were in the range of 0.34–0.39. Finally, two real cooking process were carried out where 72 min and 107 min were required to fully cook rice and beans respectively.