Investigation on energy collection characteristics of novel non-imaging cusp concentrator

Abstract

In solar energy utilization, the concentrating performance of the conventional non–imaging cusp concentrator (NICC) is degraded due to the gap design. To address this, this paper conducts structural optimization design on NICC, thereby forming a novel non-imaging cusp concentrator (N-NICC) without no light escape within the gap. On the basis of non-imaging optics and differential geometry principles, a mathematical model for the compound concentrating surface (a compound parabolic surface and a concentrating plane) of the N-NICC is constructed. Its analytical solution is obtained through differential geometry theory. Concentrating verification experiments and software simulations are conducted to investigate the solar radiation collection characteristics of this model, validating its scientific accuracy and correctness. Additionally, through concentrating experiments and optical performance analysis, it can be inferred that at various incident angle (0°, 5°, 10°, 15°, 20°, 25°), the measured light touch positions on the circular absorber in monochromatic laser and semi-darkroom natural light experiment are consistent with the theoretical values, with average relative errors not exceeding 5.37% and 0.81%, respectively. Within the incident angle range of 0-45°, the average optical efficiency and energy flux uniformity of N-NICC are increased by 5.4% and 6.63% compared with the traditional NICC. Concurrently, the annual effective working hours and monthly average total solar radiation of N-NICC are 13.3% and 5.67% higher than those of NICC, respectively. This can provide a certain reference for the structural optimization design of non-imaging concentrators and holds positive significance for achieving carbon peak.