The Research Of Photovoltaic Airflow Windows And The Building Integrated System By CFD Simulation

PV airflow windows have become more and more widely applied in recently days as the energy saving have been hotly discussed in modern society. Photovoltaic cells, as one of the most important components of the system, are able to convert solar energy to electricity. The mechanical ventilation method should be applied to cool down PV cells for the sake of minimizing the negative influence created by the cell temperature increase when the system is operated. The performance of itself and the relationship between it and the indoor environment are investigated by the CFD software program of ANSYS Fluent in this research, the simulation focuses on the performance of PV airflow window system,the effect of mechanical ventilation system and the indoor environment when the system is integrated with the specific architecture. The conclusion drawn by the research can guide to the utilization of PV system.Firstly, comparing the increase of cell temperature(6℃and20℃separately) of mechanical and natural ventilation, the conclusion can be drawn that heat flux generated by the working PV cells can be taken away by the airflow inside the window gap. Comparing the temperature change of inlet air, PV cells and inner glazing along with the increase of PV cell transmittance(15% to 20% and 30%), it is concluded that the detected temperatures were decreased. But the temperature difference is smaller than 2 degree Celsius, within the given transmittance range, the influence of that is not that significant.Secondly, the minimum airflow rate of mechanical ventilation can be acquired through the simulations for the given office which is integrated with PV airflow windows. In winter, that value is 0.75m/s. In this condition, the temperature and the air velocity of the detected positon is 20℃ and 0.19m/s, respectively. In summer, the minimum airflow rate is 1.82m/s, and the temperature and the air velocity of the detected positon is 25℃ and 0.24m/s, separately. The indoor environment is desirable at the minimum airflow rate of mechanical ventilation in both winter and summer conditions,the system is operated under energy efficient condition and can keep a desirable indoor thermal environment.