Journal of Energy Research and Environmental Technology (JERET) Print ISSN: 2394-1561; Online ISSN: 2394-157X; Volume 2, Number 3; April-June, 2015; pp. 205-209 © Krishi Sanskriti Publications http://www.krishisanskriti.org/jeret.html Solar Cooker Based on Parabolic Dish Collector for Evening Cooking using Dual Heat Storage Materials Vikrant Yadav 1 and Avadhesh Yadav 2 1,2 E-mail.: Department of Mechanical Engineering, National Institute of Technology, Kurukshetra Haryana-136119, India 1 vikrant_3133707@nitkkr.ac.in, 2 avadheshyadava@gmail.com Abstract—This paper presents an investigation of thermal performance of PCM in combination with different sensible heat storage materials (SHSMs) in a solar cooker based on parabolic dish collector for evening cooking. In the experimental setup, a pressure cooker is placed at the centre of two concentric pots containing PCM in the inner pot and different SHSMs in the outer pot. Twocases were studied by filling different SHSM (stone pebblesand iron grit) in the outer pot. During sunshine hours, this unit (solar cooker) is placed on plate of parabolic dish collector for storing the thermal energy in the SHSMs. Initially the material in the outer pot stores energy and meanwhile transfers it to the PCM in the inner pot, which further stores and transfers heat to the pressure cooker. In the evening, the solar cooker is kept in an insulator box and loaded with cooking food, where the PCM deliver heat to the food. It has been found that PCM-Stone pebblecase stores 3.6 times more heat as compared to PCM-Iron grit case.The PCM assists in cooking while the outer material assists PCM to maintain its performance. Keywords: Thermal performance, parabolic dish collector, solar cooker, phase change material, sensible heat storage materisl (SHSM), latent heat, sensible heat. 1. INTRODUCTION Cooking is a prime necessity for all people across the world. About 75% of people living in rural India fulfill their cooking energy needs from noncommercial fuels like wood from the forest which contributes to deforestation and green house effect. On the other hand price of LPG, which is another major source of energy for cooking, is rising day by day. Due to this cooking by using renewable energy sources is a burning issue. Fortunately, India is blessed with ample amount of solar radiation. This offers solar cooking as one of the most attractive options. Successful application of solar energy depends to a large extent on the method of energy storage. Energy storage not only provides bridge between supply and demand, but also improves the performance and reliability of the system. Different types of thermal energy storage system may involve only sensible heat storage (storing of energy by heating or cooling), latent heat storage (by melting or vaporizing or solidifying or liquefying) or a combination of both. If solar cookers are provided with the thermal storage unit, then there is possibility of cooking food during the off- sunshine hours. Several efforts were made for day and evening cooking using concentrating type of collectors with thermal storage. The concentrating type of collectors can be categorized into two groups based upon their applications, first achieving the high temperature range up to 300°C - 400°C in solar power plants and second, in industrial process heat applications where the temperature range required is 150°C - 250°C. The parabolic dish type concentrator has high collector efficiency so it is widely used in the area of solar cooking [1- 4]. Foong et al. [1] studied a small scale double reflector solar concentrating system with high temperature heat storage medium (NaNO 3 and KNO 3 FarooquiSuhail [4] presented a solar cooker based on Fresnel lens type collector. The proposed cooker consists of rectangular glass mirror strips mounted on wooden frame and requires one dimensional solar tracking. The maximum temperature attained in the experiment was 250°C. Heat absorption capacity of this collector was five times more than conventional box type solar cooker. With the development in the field of solar energy, the parabolic trough collector was ) and a finite element model was used to numerically analyze the latent heat storage unit. The experimental results demonstrated that the melting of phase change material occurred in 2 to 2.5 hr and reached a temperature range of 230-260℃, suitable for cooking and baking purposes. Chaudhary et al. [2] investigated a solar cooker based on parabolic dish collector with phase change material. It was observed that solar cooker with phase change material having outer surface painted black along with glazing stores 32.3% more heat as compared to PCM in ordinary solar cooker. Lecuona et al. [3] simulated a portable solar cooker of parabolic type using 1-D finite difference method. A numerical model was used to study its transient behavior with two different types of PCMs: Paraffin and Erythritol. High melting heat and conductivity of a PCM like erythritol is an advantage for fast cooking.