Modeling and Performance Evaluation of Parabolic Trough Solar Cavity-Type Receivers

Abstract

This article proposed three new designs about parabolic trough solar cavity-type receivers. The characteristics of these designs were also analytically analyzed. In the paper, the geometrical-optical method is used to analyze the absorptivity of these cavity receivers. The influences of the specular reflection ratio in absorptivity were also discussed. The geometrical-optical method was validated using the Monte Carlo Method. The study showed that the results calculated by different method can agree well. The study also showed that the proposed receiver models have less optical losses than conventional cylindrical/tubular cavity receiver under the limitation of the same-size aperture. Most of radiant energy entering into the cavity is absorbed through the initial reflection. The theoretical absorptivity of these cavities approaches to blackbody. The study also showed that the absorptivity increases monotonously with the proportion of specular reflection and the depth of the cavity.

Design and Optimization of Elliptical Cavity Tube Receivers in the Parabolic Trough Solar Collector

“…However, tube receivers are more commonly used in PTC combined with thermodynamic cycles [8][9][10]. In general, two kinds of tubes are commonly utilized in the PTC as the receiver, namely, the vacuum tube [2,[4][5][6][7][8][9][10] and the cavity tube [11][12][13]. The main advantages of the vacuum tube are the high thermal maintenances and low module cost, whereas its structure is frangible.…”

“…Sunlight is then reflected for several times and finally reached the tube receiver at the ellipse focus. There are some studies on optical performance of the solar cavity receivers [10][11][12][13]. Very limited studies have been presented to the parameter analysis and optimization of the elliptical cavity tube receiver.…”