Preliminary study on photo-thermal conversion investigation of compound parabolic concentrator for eliminate light escape in vacuum tube interlayer

The ELE-CPC (Eliminate Light Escape Compound Parabolic Concentrator, ELE-CPC) system with vacuum tube absorber is constructed to solve the problem of light escaping in the vacuum interlayer when the conventional vacuum tube absorber is coupled to CPC. The solar ELE-CPC photo-thermal conversion model is established theoretically, and the reliability of the model is validated by outdoor experiments. It is found that the average output temperature of ELE-CPC system is 366.4 K, the average thermal efficiency is 61.3%, and the maximum relative error of the theoretical model is less than 13.2%. The thermal collection efficiency of the ELE-CPC system improves with the increase of its flow rate. Evaluation of the operating characteristics of ELE-CPC showed that the useful energy obtained by ELE-CPC increased throughout the year, especially in April, the average daily utilized solar energy obtained by ELE-CPC increased by 6.9% compared with S-CPC (Standard CPC, S-CPC). Solar ELE-CPC system with such heat collection performance has a good application prospect in the fields of material drying, building heating, seawater desalination and so on.