Experimental and numerical investigation on heat transfer performance of a solar double-slope hollow glazed roof

Abstract

The glazed roof has been widely used in modern building design. Compared with ordinary glazed roof, hollow glazed roof has better thermal insulation performance, which can improve the indoor thermal environment effectively. In order to study the effects of physical parameters on heat transfer performance of hollow glazed roof. In the present work, according to the actual size of the building, an entity model of a double-slope hollow glazed roof was built based on the similar theory. The heat transfer performance of double-slope hollow glazed roof with different slope angles in hot summer and cold winter regions was experimentally studied. Results indicate that as the roof slope decreases, the effect of reducing the inner surface temperature of the roof is relatively obvious. When the roof angle decreases from 45° to 30°, the peak temperature of the inner surface decreases by about 12.2%. Then through the established numerical model, further studied the influence of related parameters on the heat transfer performance of the roof by FLUENT software based on the experimental data. The numerical results show that changing the thickness of the roof hollow layer has a more significant impact on the roof's heat transfer performance than changing the thickness of the roof glazing layer. When the thickness of both is increased by 12 mm, the peak temperature of the roof inner surface of the former decreases by 5.5%, and the latter decreases by 1.7%. Moreover, when the thickness of the inner and outer glazing is changed (that is, outside thick, inside thin and inside thick, outside thin hollow glazed roof), the roof heat transfer performance is hardly affected.