Consideration of heat transfer in pore network modelling of convective drying

Abstract

The influence of heat transfer on the drying behaviour of capillary porous media saturated with water is studied. To overcome the limitations of continuum approaches, a pore network model based on statistical physics and invasion percolation is used. The presented non-isothermal model is the first of its kind to describe free evolution of temperatures in convective drying. Gas-side mass transfer is modelled by a discretised boundary layer. Model assumptions are purely conductive heat transfer in the network and negligible viscosity. Vapour condensation is partially modelled. Simulations are conducted on two-dimensional square lattice networks. Overall drying rates and corresponding evolution of phase distributions and temperature fields are presented for mono- and bi-modal pore structures. The influence of heat transfer on phase distributions and drying behaviour is discussed in comparison with isothermal simulations.