CONCENTRATED FLUX MEASUREMENT APPARATUS FOR AN ASYMMETRICAL PARABOLIC TROUGH SOLAR CONCENTRATOR

In this work, the optical performance of an asymmetrical small parabolic trough solar concentrator is experimentally characterized by adopting a direct method to define the solar flux map on the focal region. Due to the particular geometry of the optical system, the optimal plane of concentration is 450 tilted with respect to the plane containing the focal line and the vertex line. A water cooled heat flux microsensor installed on a two-axes linear handling system is used to measure the concentrated solar flux along the optimal concentration plane of the present optical system. The collected data are interpolated to obtain the flux distribution and to determine the width of the solar image over the focal line. These results together with the values of the direct normal irradiance collected during the tests and the nominal reflectance of the parabolic mirrors allow the evaluation of the intercept factor for different areas included in the concentration region.