Design of parabolic solar concentrator to improve the optical efficiency for thermal engine generator using dual reflector Gregorian method

摘要

Parabolic Dish Solar Concentrator (PDSC) are commonly used to generate electricity from thermal energy employing Stirling engine, steam, photovoltaic and thermoelectric generator. Heat concentrator of Parabolic Dish (PD) is used for focusing radiation of the sun into the receiver that connected to the generator system. The conventional generator system is located above the focus of the primary reflector parabolic dish. This paper presents a new design of the parabolic dish solar concentrator using dual reflector Gregorian method. The design applies an additional reflector to place the engine generator in the bottom of the primary reflector parabolic dish. The design was verified using “SolTrace”, a software package for tracing the solar ray. It found that the heat flux collected was 0.73 MW/m2 for the designed parabolic with 300 cm primary diameter. This parabolic have obtained 594.65x geometry concentration ratio and 84.27% optical efficiency.