Experimental study of direct transfer of concentrated solar radiation through optical fibres to high temperature thermal applications

摘要

Employing optical fibres for transferring concentrated radiation from solar concentrators has potential advantages in terms of transmission energy efficiency, technical feasibility and cost-effectiveness compared to a conventional heat transfer system employing heat exchangers and a heat transfer fluid. The basic investigated system comprised a broadband source, collimator lens, objective lens and optical fibre as the carrier of energy to the receiver. The relationship between transmission and length of fibre is studied via simulation using the ray tracing model, LightTools®. Two different sources were defined in the system setup including a white light source and the solar simulator with similar spectral distribution as solar spectrum. The effects on transmission of varying the hydroxyl content, and the core size of the fibres are also investigated experimentally. The experimental results are then compared with simulations. The initial results indicate that the selected low OH unjacketed bulk fibre with NA=0.22 is capable of transmitting approximately 92% of the concentrated solar energy over lengths up to 10 m with less loss compared to conventional methods for direct transferring of concentrated solar radiation.