DOI: 10.5593/SGEM2014/B41/S17.040


C. Croitoru; F. Bode; I. Nastase; A.l Dogeanu; A. Meslem
Wednesday 1 October 2014 by Libadmin2014

References: 14th International Multidisciplinary Scientific GeoConference SGEM 2014, www.sgem.org, SGEM2014 Conference Proceedings, ISBN 978-619-7105-15-5 / ISSN 1314-2704, June 19-25, 2014, Book 4, Vol. 1, 307-314 pp

Perforated solar walls pre-heat the fresh air introduced in the building when the air is forced to pass through this solar heated perforated facade, the heat transfer between the fluid and the metal being intensified depending on the flow’s characteristics. Solar perforated envelope facades can be used horizontally or vertically for a variety of purposes and applications, from heating buildings to agricultural or drying process. An experimental campaign evaluated some characteristics of a certain type of solar collectors which have a major influence on the heat transfer or thermal efficiency. Two types of experimental investigation were performed: flow analysis with Particle Image Velocimetry method correlated with evaluation of the thermal efficiency of the model. The complex fluid dynamics generated by certain types of the geometries can be directly linked to the temperature increase of airflow. The perforated panels were placed on a rectangular box with acrylic glass walls. The box is connected through a circular pipe to an exhausting fan, forcing the ambient air to pass through the perforated panel. After positioning of each perforated cladding, the box is sealed, in order not to have leaks which might perturb the tests. The study reveals the importance of certain characteristics of solar collectors which can improve with almost 20% the thermal efficiency. Changing the geometry of the perforations is generating complex fluid dynamics, resulting in a higher efficiency of heat recovery of these devices. Extended to a real scale building, we can obtain high energy savings for pre-heating the fresh air introduced. On the one hand, it can be an effective solution for major refurbishment of buildings and on the other hand Unglazed transpired solar walls improve their thermal efficiency with a significant rate for the case of innovative perforations.

Keywords: unglazed transpired solar wall; lobed perforation; fluid flow; thermal