Design and thermal insulation simulation of nano-SiO2 foam concrete and vacuum insulation panel system for building exterior wall insulation

Efficient thermal insulation of building exterior walls is one of the critical strategies to improve building energy efficiency. To achieve a better thermal insulation effect for the building exterior wall insulation system, this paper conducts a composite design by synergistically adjusting nano-SiO2, the composite foaming agent of foam concrete, and vacuum insulation panels(VIP). The objective is to develop a building exterior wall insulation board with superior thermal insulation performance. Thermogravimetric analysis of the foam concrete shows that the synergistic effect of an appropriate amount of nano-SiO2 and the composite blowing agent can effectively improve the thermal stability of foam concrete. The Comsol Multiphysics numerical simulation software was used to construct spatial physical models of different combinations of foam concrete insulation boards and VIP. Transient heat transfer simulations of the composite insulation boards were carried out under different thermal and humidity coupling physical fields to analyze the thermal insulation effect of each composite insulation board Scheme. After verification, Scheme 2 “foam concrete + VIP + foam concrete,” demonstrates the optimal overall thermal insulation effect. Therefore, Scheme 2 is finally selected as the thermal insulation system with the best thermal insulation performance.