Heat Transfer Studies on Air Cooled Spiral Radiator with Circumferential Fins

摘要

Heat exchangers find use in several applications such as in automobiles, refrigeration, air conditioning, and water treatment plants. Radiators are a class of heat exchangers in which heat transfer occurs by means of air flowing across a series of finned tubes, eventually decreasing the temperature of the fluid to be cooled. The energy crises of recent times have necessitated improved heat transfer rates and at the same time the need for making heat exchangers smaller and more energy efficient. A simple modification has been carried out in the existing configuration of radiators, with a view to improve its efficiency and has resulted in the development of a compact spiral radiator against a standard air cooled fin and tube radiators used commonly especially in automobiles. In this configuration, water flows through spiral tubes, which are fitted with circumferential fins and air flows across the tubes for bringing about heat transfer.A numerical investigation has been carried out on the spiral radiator to study flow characteristics and thermal performance by means of local element by element analysis utilizing ε-NTU method. Experiments were performed and the results after comparison with the theoretical values were found to be promising. From the experimental data, a correlation among the important dimensionless numbers has been obtained using GARCH tool.