Improvement of thermal performance of a solar chimney based on a passive solar heating system with phase-change materials

Passive solar systems such as solar chimneys need solar radiation in order to work. Therefore, they cannot present stable natural ventilation when solar energy vanishes: to have a more robust and stable condition, solar energy should be stored during the day and released back during the night. Phase change materials can save additional thermal energy during the day and release it during the night in order to facilitate stable ventilation. In this study, a CFD simulation has been performed to investigate the effect of phase-change materials (PCM) utilization in the solar chimney to provide a stable temperature and air flow rate for a guardroom. The simulation was carried out for a whole day in winter in two cases: with and without PCM usage. The results show that use of PCM as an energy storage device significantly enhances the temperature stability of the guardroom.