A self-driven mechanical ventilated solar air collector: Design and experimental study

In order to reduce the limitation of solar air collectors in application and apply them to some places where the urban power grid can not reach. The new concept of self-driven mechanical ventilated solar air collector (SDSAC) was proposed and realized in actual device. The structure and electrical system of SDSAC were designed and fabricated based on the above objective. Experimental studies were carried out to investigate the working performance of SDSAC by comparing it with a natural ventilated solar air collector (NVSAC). The results indicate that the small-scale NVSAC is unstable and less efficient, and the phenomenon of back flow occurs frequently during the working process. The self-sustained operation of SDSAC was realized in the experiment, and the working process can be categorized into five stages based on the outlet temperature of SDSAC. Specially, there exists a quasi-steady-state in which the outlet temperature, the flow rate and the thermal efficiency are almost constant for about 2 h, and the average thermal efficiency of SDSAC can reach up to 49.2%, which is far better than NVSAC with an average thermal efficiency about 11.5%. Optimization work should be done to achieve constant working performance in the full operation time. (C) 2019 Elsevier Ltd. All rights reserved.