Research Article

Performance analysis of parabolic dish solar cooking system with improved receiver designs

¹ Department of Mechanical and Industrial Engineering, University of Dar es Salaam, P.O. Box 35091, Dares Salaam, Tanzania
² Ministry of Energy, P/Bag 309, Lilongwe, Malawi

^* e-mail: austintheu@hotmail.com

Received: 4 January 2022
Received in final form: 27 November 2022
Accepted: 27 November 2022

Abstract

Lack of access to clean energy for cooking and heating applications is one of the challenges faced by households in developing countries. Solar cooking is one of the solutions, but suffers low adoption and utilization due to various challenges including technical limitation. This study investigated initiatives on improving the technical viability of parabolic dish solar system used for direct cooking by focusing on the receiver. Three receiver prototypes namely; Insulated, Oil-filled and Air-filled, all incorporated with a base circular ring, were constructed and their performance was compared experimentally with the conventional receiver. The maximum temperature inside cooking vessels were 154 °C, 99 °C, 141 °C and 128 °C while standardized stagnation temperature and first figure of merit (F₁) were found to be 159 °C, 100 °C, 154 °C and 109 °C; and 0.26, 0.15, 0.54 and 0.17, for systems with insulated receiver, oil-filled receiver, air-filled receiver, and conventional receiver, respectively. The second figure of merit (F₂), overall heat loss factor, heat exchange factor and optical efficiency were determined as 0.36, 0.15, 0.14 and 0.33; 59.7 W/m² K, 28.6 W/m² K, 20.49 W/m² K and 73.4 W/m² K; 0.18, 0.75, 0.69 and 0.23; 25%, 4%, 4% and 17%. The study found that the cooking system with Insulated Receiver gave more merits and was established as the best.