ANALYSING THE PERFORMANCE OF SOLAR THERMAL COLLECTORS BASED ON NANOFLUID

Abstract - Mankind is living in the arena of evolution of technology in which energy is an integral part. However, this enrichment of science and technology has opened new pathways for energy consumption and generation as well. Raise of population density is another root cause for energy demands. Fossil fuels are depleting at faster rate and leaving carbon footprints on environment. In this scenario, it is inevitable to depends on renewable energy sources which are inexhaustible, eco-friendly and abundantly available in nature. Amid all renewable sources, effective utilization of solar energy is a viable alternative to meet the growing energy demands, particularly for low temperature applications. While consumption of solar energy for various domestic applications is not new, but it is suffering from lower effective energy conversion problem.Solar collectors are the device that absorbs the incident solar radiation and converts into useful form. Among different types of collectors, solar flat plate collectors (SFPC) are the noteworthy devices to convert the incident radiation into heat energy of working fluid. In view of enhancing the thermal efficiency of collectors, there are two major approaches as either changing the geometry and operating parameters or enhancing the properties of working fluid. Since, various geometrical and operating parameters and modifications are more or less saturated, present work is focused on enhancing the thermophysical and optical properties of working fluid by suspending nanoparticle as an approach for effective conversion of solar radiation into useful heat energy.Thermophysical properties and their influence on thermal performance of SFPC are estimated using the empirical correlations available in open literature and comparisons are made with the experimental outcomes. It is noticed that a substantial variation exists between the analytical and experimental outcomes. Thus, the influence of each parameter on collector efficiency is critically examined. Both thermal conductivity and viscosity of all working fluids are experimentally measured and compared with the existing correlations. Key Words: Solar flat plate collector, solar device, solar air heaters, solar energy.