Evacuated Tube Solar Cooker with Ethylene Glycol as Sensible Heat Storage Medium

This paper discusses the design and performance evaluation of an evacuated tube solar cooker with sensible heat storage to aid continuous cooking during interruption by the cloud. Besides, the experimental setup validates the theoretical value. The process of cooking, water boiling requires heat at a minimum of 100. C, and it is possible to attain higher temperatures in a shorter time if we use the HT (Heat Transfer) fluid of lower specific heat value. Ethylene glycol, a commercially available HT fluid with a specific heat of approximately 2.5 kJkg(-1) K-1 is used as HT fluid cum sensible heat storage medium in the experimental setup. The lower specific heat value of ethylene glycol helps in achieving a higher temperature in lesser time. On a sunny day HT fluid attained the maximum temperature of 106 degrees C. This setup took 1 to 1.5 hours to cook 0.5 kg of raw rice whereas conventional box type cooker takes 2.5 to 3 hours to cook the same amount of rice.