Thermal and hydraulic analysis on a novel Trombe wall with venetian blind structure

摘要

This paper aims to present a CFD investigation into the heat transfer and friction characteristic of a Trombe wall equipped with venetian blinds. This involved (1) development of a CFD model; (2) dedicated experiment for verification of the model; (3) modelling result analyses and conclusion. Based on experimental data, the model was validated and it was able to yield satisfactory predictions. The characteristics of the Trombe wall with venetian blinds inclined from 5 degrees to 85 degrees were investigated. The Nusselt number and friction factor for Reynolds number within the range of 4173-16,693 were also achieved in the simulation. Analyses of the research results indicated that smaller slat angle helps enhance the outlet air temperature and solar thermal efficiency, while increasing the Reynolds number leads to decrease in outlet air temperature and increase in solar thermal efficiency. The empirical equations of heat transfer and flow resistance were proposed. The Nusselt number value of the venetian blind increases with the increase of the Reynolds number value and decrease of the slat angle. In addition, the Nusselt number is proportional to the range of 0.422-0.461 power of the Reynolds number. The friction factor value decreases with the increase of the Reynolds number value and the slat angle. (C) 2016 Elsevier B.V. All rights reserved.