Improving the performance of the finned absorber inclined rooftop solar chimney combined with composite PCM and PV module

Abstract

Solar Chimney (SC) can play a significant role in energy consumption reduction of ventilation applications. The primary purpose of this study is to ameliorate the performance of an inclined rooftop SC integrated with the Phase Change Material (PCM) and Photovoltaic (PV) module, called the SC-PCM-PV system. To this aim, the effects of using finned absorbers and composite PCMs on the performance of the SC-PCM-PV system are investigated for the first time. A 3D-CFD model is developed via the finite volume method to examine the impact of various design parameters, including fin number, fin thickness, PCM type, and PCM mass on natural ventilation duration, ventilation capacity, and power output. The results indicate that increasing the PCM mass decreases the ventilation capacity for the finless cases and does not significantly enhance ventilation duration. However, increasing the PCM mass enhances the ventilation capacity, ventilation duration, and power generation for the finned cases. Ventilation capacity and duration are improved by 7.7% and 17.6% when a finned absorber is used. It is revealed that copper-foam-based composite PCMs extend the ventilation duration of the SC-PCM-PV system. Furthermore, employing Sodium Acetate Trihydrate/Copper Foam (SAT/CF) as the PCM enhances ventilation capacity up to 19.8% compared to an SC combined with a PV module called the SC-PV system. Also, using paraffin/copper foam (Pa/CF) as the PCM provides the highest power output (5.54 kWh) and ventilation duration (22 h and 30 min), approximately 16% and 101 % more than those of the SC-PV system. Conducting a case study for Shanghai city, it is demonstrated that the SAT/CF and Pa/CF are decent candidates to provide natural ventilation for commercial (77.9% of ventilation capacity) and residential buildings (83.1% of ventilation capacity), respectively.