Optical and thermal performance-cost evaluation for different segmentation of a novel equal-length multi-section compound parabolic concentrator

To solve the problems of high production and maintenance cost, poor substitutability and low standardization level of the compound parabolic concentrators (CPCs) with glass mirror curved concentrator for building integrated solar system, an alternative equal-length multi-section planar splicing concentrator is introduced. This work mainly focuses on how to realize higher performance-cost ratio through different planar segmentation of the curved concentrating surface. Based on optical and thermal modelling, spatial energy flux density distribution, optical efficiency, photothermal efficiency of the CPCs whose concentrating surface containing 15, 13, 11, 9, 7, 5 and 3 pairs of equal-length planes were investigated. Results show that the average output temperature of the CPC containing 15 planes is 364.4 K, and the photothermal efficiency is 61.63%. With the decrease of the number of segments, the photothermal efficiency gradually decreases. However, it brings benefits that the peak of energy flux density becomes gradually smaller, the thermal stress in the glass tube gets reduced, and the CPC manufacturing cost is greatly reduced. Considering comprehensive photothermal performance and cost, CPCs containing 9–15 equal-length planes could trade off between the performance and cost. The findings can promote the planarization and standardization of CPCs for building integrated solar system.