Heat loss analysis of a parabolic type dish cooker

Present communication provides a detailed thermal loss analysis of dish concentrator solar cooker. The heat losses that occurs from side walls, bottom surface and top lid of the cooking vessel are reported in this paper. The convective, radiative and conductive heat losses are calculated followed by the calculation of performance index and energy efficiency of cooking vessel. The parameters such as wind speed, hot water temperature, ambient temperature, steam temperature and solar radiations were measured on a sunny day under climatic conditions of Bhopal, India. The concentration ratio of the solar dish cooker was calculated to be 27. It was found that highest losses occurred at the side surface with maximum value reaching 189 W/m2. It was observed that the side losses increases with increase in wind speed. The experimental results show that performance index lies in the range of 24.79 to 26.62 and the mean energy efficiency was determined to be 94.29%