Experimental Assessment on Thermal Performance and Efficiency of Pyra-Box Solar Cooker

Abstract

Low-cost Pyra-box type solar cooker was designed, prototyped and tested. The energy efficiency of the cooker was experimentally evaluated. The experiments were conducted in a clear day in Junuary 2014 in Hawassa University, Ethiopia. Details of temperature distributions and their time dependences were measured. Temperature measurements were taken at intervals of 30 seconds with K-type thermocouples connected to a multi-channel digital data-logger. The maximum temperature obtained in a pot containing 500 CC amount of water was 94 °C and 88 ^oC for pyra-box and conventional box cooker respectivelly. The second experiment was conducted using oil fluid and the maximum temperature attained within two hours by the pyra-box cooker, Tpc, was 104.81^oC. The total overall size of pyra-box cooker was 25% less than the box solar cooker. The average energy efficiency of CSC and pyra- box cooker was about 15.4 % and 26.5 % respectively. At 50^oC temperature difference they had 8% energy efficiency difference. Finally pyra-box cooker can increase an average of 11 % thermal efficiency by decreasing 25% total collector area.

Key words: Performance, Pyra-Box, Solar Cooker, Thermal Analysis