Indian Journal of Science and Technology

Abstract

The Storage and transportation of some goods such as vaccines, foods and other items requires cold storage. Today most of refrigerators at off-grid areas run on generators and batteries. In this context, solar refrigerator without use of battery is promising option to solve the problems. This paper describes experimental investigation of solar powered battery-free refrigerator, with use of cold thermal bank, to provide cooling at night. The refrigerator system is designed for a capacity of 150 liter. The supply of electricity to run AC compressor is provided by solar panels through the inverter. In addition to this, provision is made to work at night, by use cold thermal storage bank which provides cooling effect at night and maintains temperature by preventing thermal fluctuation caused by intermittence supply of electricity by PV panel. The solution of propylene glycol with water of 20:80 by volume is used as thermal reservoir. When the refrigerator is powered by PV panels, the solution takes 3½ hour to reach to reach -100 C with full load condition. The aqueous solution of 10 Liters can provide cooling for almost 17 hours with full load condition without running refrigerator. For domestic and small business applications, this type of solar refrigerator can be used .It can be ideal solution to store vaccines or food, which requires low temperature during transportation

Keywords: Cold Storage, Propylene Glycol, Thermal Reservoir, Vapor Compression Refrigeration System