DESIGN, SIMULATION, CONSTRUCTION AND PERFORMANCE EVALUATION OF A SOLAR BOX COOKER

ABSTRACT
solar box cooker is a device that converts solar energy into useful heat in a confined space. The solar cooking system which captures and utilizes the abundant solar energy was designed, simulated, constructed and tested. Plane reflectors were used to concentrate solar radiations continuously on the collector which result to heat gain. It is usually difficult to manually track the movement of the sun and the use of a tracking device may be very expensive. Hence, plane reflectors were used. At the initial stage, the typical metrological year (TMY) solar data of Zaria obtained was processed to obtain the monthly average daily solar resources of Zaria using the solar radiation and weather data processor TYPE 109 component of TRNSYS 16 software. The month with the least average daily solar radiation was considered as the design month and the result shows that the month of August has the least solar radiation and therefore, considered as the design month.Secondly, the solar cooker was constructed at Ahmadu Bello University, Zaria Mechanical Engineering Workshop using various tools for cutting and machining.Thirdly, the solar cooker was tested at Mechanical Engineering Department of ABU between 28^th and 31^st of October, 2016. During the course of the testing, it was observed that in general the performance of the cooker was so encouraging because it cooked rice within an hour. The maximum stagnation temperature and that of absorber plate temperature were found to be 141^oC and 143^oC respectively. The cooker was simulated using TRNSYS and EES software. The simulated results were compared with the experimental results to determine the level of agreement between the two using Root Mean Square Error (RMSE) and Nash Sutcliff Efficiency (NSE) statistical tool. The RMSE results are 4.8203^oC and 2.604^o While the NSE results are 0.9867 and 0.996. These results show that the experimental values and the simulated values are in good fit.The regression line for the experiment and simulation were obtained and were used to compute the cooking power of the cooker. At 50^oC, the experimental and simulated cooking powers . For the average solar radiation incident on surfaces at different time intervals for the 4 conservative days, the regression line showing line of best fit for the co-efficient of determination (r²) was found to be 91.87. And also, for the variation of simulated and experimental collector efficiency, the co-efficient of determination (r²) for both the simulated and experimental results were found to be 98.8 and 94.1 respectively. And the percentage of energy increment due to third reflector was found to be 84.5