Numerical Analysis of Novel Solar Central Receiver Using Different Types of Heat Transfer Fluids /

Abstract

Solar energy is considered as a cheap source of renewable energy for meeting daily energy demand. To harness the solar energy efficiently, solar power tower (SPT) has gained huge attention currently, apart from highest capital cost and technical maturity. Central receiver is a major component which converts solar flux into thermal energy, although it carries radiation and convection heat losses. In this study a new design of central receiver is introduced to meet the current challenges related to receiver such as thermal losses. The proposed design utilizes double glazing around an absorber which behaves as radiation trap and reduce radiative and convective losses. The absorber of proposed receiver utilizes milli channels for the passage of pressurized air and metallic tube structure to pass liquid phase heat transfer medium. The respected design is analyzed numerically by using different heat transfer fluids such as therminol oil, molten salt (solar salt ) and liquid meta (molten sodium). The methodology adopted in numerical analysis was finite volume method (FVM) and SIMPLE algorithm used to couple pressure and velocity terms. Sensitive analysis is carried out on different flow parameters of receiver such as temperature, pressure and turbulence kinetic energy by altering mass flow rate of heat transfer fluids and solar flux condition. At higher mass flow rates of liquid sodium, receiver temperature drops significantly as compared to solar salt and therminol oil. Liquid sodium has shown the thermal efficiency of 82.3%, which is considered as quite significant in receivers’ performance and development.