Numerical Simulation of Heat and Moisture Transfer of Wall with Insulation

Abstract

This paper improves the heat-moisture coupling transfer model with temperature and relative humidity as the driving force, and regards the effective thermal conductivity and vapor permeability of the wall material as a function of temperature and relative humidity. The latent heat generated by steam diffusion was introduced into the model and the model was numerically calculated using the finite element software COMSOL Multiphysics. The calculation results show that as the thickness of the insulation increases, the heat transfer and moisture transfer inside the wall slow down. When the temperature gradient or the water vapor concentration gradient on both sides of the wall increases, the heat transfer rate will also increase. But they will gradually stabilize. After reaching a steady state, there will still be moisture and temperature transfer due to the existence of the gradient.