Numerical Modelling of a Linear-Fresnel-Collector’s Receiver Optimized for Equatorial Regions Using Ansys Fluent

Abstract:

The present document describes the numerical simulation of a Fresnel-type solar receiver conceived under the context of a larger project from National Polytechnic School (EPN) in Quito–Ecuador, which consists of a low-concentration middle-range-temperature linear Fresnel collector to be installed in the university campus. Given that Quito is located exactly on the equator, the receiver was optimized for equatorial regions by inserting a radiation input corresponding to the Typical Meteorological Year of the same location using solar-radiation data collected in the campus and properly validated. The chamber in the receiver is formed by an absorber and two reflectors in a trapezoidal configuration, having a glass in the bottom to enclose the cavity. The absorber in the top is painted with a high selective coating while the aluminum reflectors present a high reflectivity. The radiative effects were computed by the Discrete-Ordinates model, and in order to emulate the greenhouse effect produced by the glass, a two-spectral-band model with the breakpoint at 2500 nm was set up. The absorber and the reflectors were modelled as opaque surfaces, and the glass as semi-transparent. For glass absorption and scattering, a non-gray model was selected in order to distinguish properties in the two bands. Likewise, given the temperature changes inside the receiver, natural convection was modeled for the air using an ideal-gas fully-compressible formulation. The numerical calculation led to determine a maximum temperature in the absorber of 406 K under the best conditions of the sensitivity analysis, and no higher than 380 K under the conditions established …

Año de publicación:

2021

Keywords:

Fuente:

google