Optical efficiency measurement of solar receiver tubes: A testbed and case studies

Abstract

Knowledge of the parabolic-trough collector (PTC) solar receiver performance is essential in solar thermal power plants using this type of collector technology because it is the component responsible for collecting the solar radiation and transferring it in the form of thermal energy to the heat transfer fluid. Its performance depends on two parameters, heat loss and the optical efficiency of the solar receiver tubes. Therefore, the receiver optical efficiency must be known for correct sizing of a PTC solar field. This article presents an outdoor testbed developed to measure the optical efficiency of solar receiver tubes under real solar radiation conditions, including a detailed description of the system developed, working principle, test procedure, and performance results for two sample receiver tubes tested showing proper system functioning. Keywords: Parabolic-trough solar collector, Receiver, Optical efficiency, Outdoor testbed, Absorptance, Transmittance