Analysis of gap heat loss in external thermal insulation system of passive low-energy-consumption building based on CFD

Abstract

The extra heat loss of a horizontal gap and a vertical gap formed by thermal insulation plate splicing is numerically studied by computational fluid dynamics. Three combinations of heat transfer modes are designed for three heat transfer modes, and the temperature, velocity distributions, and extra heat loss of the air layer in the gap under different combinations of heat transfer modes are obtained when the temperature difference is 22 K and the thickness of thermal insulation plate 300 mm, to determine the proportion of the heat loss of each heat transfer mode in the total heat loss. The results show that the main mode of heat loss in the horizontal gap is heat radiation, while the main mode of heat loss in the vertical gap is heat convection. The horizontal gap has little effect on heat loss, and the vertical gap has a great effect on heat loss.