Numerical Investigation on the Effect of Vertically Oriented CPC on Spillage Loses in Evacuated Tube-Based Power Tower Receiver

The existing design of the evacuated tube-based solar power tower (ET-SPT) receiver suffers greatly from optical losses due to optical spillage; where some reflected radiation escape through the gaps between the receiver tubes, and some miss the absorber due to difference in the diameters of the glass cover and the metallic absorber tube.It is aimed in the current work to minimize the concentrated solar power spillage losses at the receiver.Potential of integrating compound parabolic concentrator in the ET-SPT receiver design was investigated.A proposed methodology of a W-shape cavity, compound parabolic concentrator (CPC) coupled with an evacuated tubular absorber, with 40 and 70 mm tube and glass diameters, respectively was designed and numerically analysed for optical performance using ray tracing software TracePro.Parameters considered in the investigation of the vertically oriented receiver design (CPC + Vacuum tube) comprise of glass tube and absorber diameters, distance between the tubes, and the angular distance between the farthest heliostats to the east and the west of the tower.Simulation results have shown that flux on target (receiver) with CPC is about 3 times more than that of ETR without CPC.Significant improvement in the receiver optical performance is achieved by minimizing the amount of spillage loses from 40 to 11 with an average receiver optical efficiency of 75. © 2023, Institute of Technology PETRONAS Sdn Bhd.