Solar Energy, Vol.218, 563-570, 2021
Performance analysis of Scheffler dish type solar thermal cooking system cooking 6000 meals per day
The escalation of energy demand in both developed and developing countries has prompted people to search and utilize clean and sustainable energy resources. Omshanti Retreat Centre (ORC) situated in Gurugram, Haryana, India utilizes solar energy to meet most of its energy demand. It has installed Scheffler dish type solar thermal cooking system having a capacity to cook 6000 meals per day in the year 2001 and is being utilized to cook food three times a day for approximately 200 days per year. The present research was conducted to study the performance of the solar thermal cooking system both experimentally and analytically; identify areas from where heat losses are occurring in the system and suggest steps that should be taken for improvement of overall system performance. Experiments were performed for seven consecutive days at ORC during summer. The system consists of twenty eight collectors arranged in such a way that a pair of Scheffler reflectors of 10 m2 aperture area concentrates solar radiation on one absorber. Thermal efficiency of 70?80% was obtained for the collectors experimentally for an average direct normal irradiance of 800 W/m2. The overall system efficiency was estimated to be 25% which suggests significant losses in the overall process. The research identified the areas which act as sources for heat losses from the system.