Improved Receiver Design Concepts for Parabolic Dish Direct Solar Cooking Systems

In developing countries, solar cooking technology is considered one of the key measures in dealing with deforestation and environmental pollution.  However, their adoption and utilization have been insignificant due to social, cultural, and technical challenges, among others. For parabolic dish direct solar cookers, one of the critical and most important components of the system is a receiver since its performance greatly affects the entire system. This paper presents part of the findings of the study which investigated the prospects of improving the technical performance of parabolic dish direct solar cooking systems by focusing on the identification of prospective heat loss reduction mechanisms on the receiver. The study identified the Insulated (IR), Air-filled (AFR), and Oil-filled (OFR) receivers with Base Circular Rings (BCR) as alternatives to the Conventional Receiver (CR) System. Tests were conducted using procedures and protocols given by the American Society for Agricultural Engineers (ASAE). The test results showed that the average power developed by the systems was 185 W for the IRBCR system, 90 W for the OFRBCR system, 92 W for the AFRBCR system, and 118 W for the CR system. The standardized cooking power for a temperature difference of 50oC, PS (50), was 291 W for the IRBCR system, 11 W for the OFRBCR system, 272 W for the AFRBCR system, and 142 W for the CR system. The results further revealed that the overall efficiencies were 23% for the IRBCR system, 9% for the OFRBCR system, 12% for the AFRBCR system, and 18% for the CR system. The receiver efficiencies were found to be 27% for a system with IR, 11% for a system with OFR, 14% for a system with AFR, and 21% for a system with CR. The study concluded that the performance improved when the system with the IR was used while the magnitudes of the performance parameters of the AFR and OFR were lower than the CR system.