External wind on the optimum designing parameters of a wall solar chimney in building. (December 2020)

• Record Type: Journal Article
• Authors: Wang, Qingyuan; Zhang, Guomin; Li, Wenyuan; Shi, Long
• Is Part Of: Sustainable energy technologies and assessments. Volume 42(2021)
• Publication Date: 2020-12
• Subjects: Trombe wall -- Wind-driven natural ventilation -- Buoyancy-driven natural ventilation -- Cross ventilation -- Solar energy -- Optimization design; Renewable energy sources -- Periodicals; Energy development -- Technological innovations -- Periodicals; Electric power production -- Periodicals; Energy storage -- Periodicals; 333.79
• DOI: 10.1016/j.seta.2020.100842
• Languages: English
• ISSNs: 2213-1388

Abstract

Highlights: External wind affects the optimum designing parameters of a solar chimney. Solar chimney with various cavity depths and inlet heights were analysed. Wind-driven force can largely avoid reverse flow at the outlet of chimney cavity. Previously obtained optimum cavity depth increases after considering external wind. Solar radiation seems to show limited influences on the airflow characteristics. Abstract: Solar chimney is a reliable renewable energy system that enhances the natural ventilation to reduce the energy consumption in buildings. Under the fact that previous optimization designs usually ignore the external wind, the impacts of external wind on the optimum designing parameters are then investigated. It is confirmed that external wind could affect its optimum designing parameters, which are different from those previously obtained value in the literature without considering the external wind. For the analysed wall solar chimney, it was known that previously obtained optimal cavity depth of 0.2–0.3 m is no longer applicable under the external wind, and the optimal value rises to 0.4–0.5 m, while the same applies to inlet height/area. Solar chimney performance is enhanced under the external wind, which is not only because of the incoming wind flow from the room opening but also the reduced air resistance. It was observed that increased solar intensity shows limited influences on the overall airflow characteristics. Solar chimney performance also presented a generally enhanced trend under a low external wind speed, but a strong wind could dominate its performance with limited fluctuation even though the wind angle is higher as 45°. It was known that the airflow rates through the solar chimney are largely hampered with a small cavity depth (i.e., smaller than 0.2 m) and inlet height under the external wind. And the airflow profiles are less affected when both of cavity depth and inlet height are bigger than 0.2 m. The obtained research outcomes could provide a technical guide on the optimization design of solar chimney in buildings.