Thermal performance assessment of a novel hot box solar cooker cum dryer: An experimental feasibility study

In this work, the authors purposely designed, fabricated, and experimentally studied a novel and economical hot-box cooker cum drier (HBCD) for low-income households of Indian states who still don't have access clean energy fuels due to poverty or their typical location-based problem. This HBCD has been found suitable for cooking and drying all common edible foods in sunny climates and can dry almost all edible stuff at the required heat transfer rate. Remarkably, potential sensible heat storage (carbon black powder) has been incorporated beneath the cooker's cooking plate to improve cooking performance in low environments. The cooker was experimentally studied during the different seasons in India, such as summer, rain, and winter, to assess its year-round performance. Outcomes showed that HBCD can perform effectively during the rain and winter seasons, while it is excellent in summer. Results of the experimental studies exposed that HBCD had a thermal efficiency of about 46.71 %, 41.8 %, and 30 %, drying efficiency of about 52.01 %, 49.58 %, and 50 %, heat transfer rate of about 121.88, 119.4, and 102.1 W/m^2oC, and cooker opto-thermal ratio of about 0.179, 0.178 and 0.179, respectively for the summer, rain, and the winter season. Experimental results and the feasibility analysis show that the system can cook almost all types of food within 2:30 h for a family of 4–5 members and dry the different edibles (up to 2 kg) within the same duration in a sunny environment. The system costs approximately $42.75 and provides many health and financial benefits to its users. It is the first solar cooking cum drying system that performs on a heat storage medium.