Numerical Investigation of Scheffler Solar Concentrator Receivers for Temperature Distribution and Steam Generation Rate.

Abstract

Concentrated Solar Technology (CST) is a device which can concentrate solar radiation using mirrors or lenses to produce temperatures in the range of 100⁰C to 450⁰C or more.Scheffler solar concentrator as a CST system with fixed Focus was initially developed for direct cooking by concentrating solar energy in the kitchen but now used for generating steam and providing process heat.The receiver is the element of the system where the radiation is absorbed and converted to some other energy form. Receiver which contains a working fluid to be heated placed at the fixed focus of Scheffler concentrator. The working fluid is usually water to thermic fluid.Scheffler solar concentrator of 2.7m² area has been taken for experimentation. Cylindrical and Conical shape receivers of 8 liters capacityare considered for analysis. Thermal efficiency of receiver is calculated on the basis of parameters like shape of receiver, initial heating of inlet water (50^oC), tilting of receiver (45^o), and receiver with glass cover for steam pressure up to 3 bars. A numerical analysis is performed for cylindrical and conical receiver using Fluent-15 CFD package. CFD analysis used to study the temperature distribution in receiver and mass of evaporated water quantity orsteam generating capacity for one bar pressure absolute.Finally numerical results are compared with experimental results.The result shows good agreement between numerical and experimental values of mass flow rate of steam with maximum deviation 9 % and 10.21 % for cylindrical and conical receiver respectively.