Numerical Study of Pre-Ventilation Effects on Cabin Temperature Using Solar Sunroof

Abstract

When a vehicle is parked under the summer sun, to avoid the passenger discomfort caused by high cabin temperature, the performance of forced ventilation, which is called pre-ventilation, using a solar sunroof integrated with a photovoltaic (PV) cell to reduce cabin thermal load is investigated numerically in this study. The vehicle pre-ventilation system is composed of a solar sunroof, DC/DC converter, and air handling system. The indoor thermal load is reduced by the hot cabin air that moves when outside air is supplied to the cabin. The simulation model is established with the component and system model approach using Dymola, and the numerical analysis results are compared with the experimental data. Using the validated model, pre-ventilation performance is analyzed with 40-, 80-, and 120-W PV cells in each solar sunroof system. The results indicate that the 40-W PV cell in the solar sunroof is sufficient for this pre-ventilation application considering cost and cabin thermal comfort performance. Further, the effects on cabin space and DC/DC converter efficiencies were investigated. The analysis results show that cabin volume slightly affected cabin temperature, whereas the efficiency of DC/ DC converter was not significantly affected by cabin temperature reduction.