Investigations of equilibrium moisture content with Kelvin modification and dimensional analysis method for composite hygroscopic material

This paper proposes a V-shaped cone model to modify the Kelvin equation and thus obtaining an accurate connection between the effective aperture of hygroscopic material and its governing factors. A dimensional equation of equilibrium moisture content is presented based on the modified Kelvin equation. A series of experiments assessing the pore feature, mechanical property, performance of adsorption/desorption and MBV (moisture buffering value) of homemade hygroscopic material are conducted. The effective aperture of hygroscopic material is accurately modified by the angle θ of the V-shaped cone model. A dimensional equation of equilibrium moisture is established by the specific surface area, temperature and humidity, and an effective coefficient of equilibrium moisture is put forward. Deviation between the calculated results of dimensional equation and the tested results of MBVpractical are modified by compressive strength. This research mainly contributes to establishing a significant basis for selection and application of hygroscopic material and providing boundary conditions for further Computational Fluid Dynamics (CFD) study.