Thermal Performance Analysis Of Prefabricated Ribbed Sandwich Wall Panels

In recent years,sandwich wall panels have received widespread attention in research and produce,but most of the research focus on the mechanical properties of composite wall panels.There are few studies on the thermal performance of sandwich wall panels.This paper takes the sandwich concrete composite wall panels which consist of two steel reinforced concrete layers,EPS insulation layer and shear connectors as the research object.Besides,the material of the connector,the structure of the GFRP connector,the spacing of the concrete ribs,the thickness of the insulation layer,the thickness of the concrete layer,and the concrete edge sealing are used as parameters to analyze the thermal performance of the prefabricated ribbed sandwich wall panels.A steady-state three-dimensional heat transfer model has been established for numerical simulation to evaluate the thermal performance of sandwich wall panels.In case of control the rib spacing is 200mm and thickness of wall panel is 150mm,the K-value of the prefabricated ribbed sandwich wall panel with diagonal web GFRP connectors is 25.11%lower than the wall panel with diagonal steel bar,and wall panel with diagonal web GFRP connectors is 51.72%lower than the typical wall panel with flat steel reinforced concrete layers.Furthermore,the K-value of all ribbed sandwich wall panels are lower than the typical wall panel with flat steel reinforced concrete layers,the K-value of all sandwich wall panels with GFRP connectors are lower than the wall panels with diagonal steel bar.The thickness of the insulation layer has the most strongly impact on the thermal performance of sandwich wall panels,the wall panels with GFRP connectors are less affected by thickness and rib spacing.In terms of heat dissipation,the area of the concrete ribs has the largest heat dissipation.The concrete edge sealing greatly extends the edge thermal bridge inward to the insulation area.Edge sealing materials with low thermal conductivity can reduce the adverse effects of edge thermal bridge.A simplified method and correction coefficient applicable to one-dimensional heat conduction calculation are presented,which makes the calculation of heat transfer coefficient convenient and accurate.In this paper,the heat transfer models of T type joints thermal bridge and windows are established,the heat transfer under different thermal insulation forms and window parameters is also analyzed.For T type nodes,the thermal bridge effect can be eliminated by the external mounted GFRP wall panels system and the thermal performance of GFRP wall panels panel system is far superior to that of other insulation forms.Keeping the inner surfaces of Windows flush with the inner surfaces of the sandwich wall panels reduces heat transfer and eliminates condensation.Similar to sandwich wall panels,the thermal performance of windows is sensitive to the change of air layer thickness.