Numerical simulation of a novel regenerative heat exchanger with combined sensible-latent heat storage matrix

A new rotary regenerative heat exchanger with combined sensible-latent heat storage matrix was proposed. A local thermal non-equilibrium model with three energy equations for fluid, sensible heat storage material, and latent heat storage material in the porous matrix was developed. Rotary regenerative air preheaters (RAPHs). The RAPHs with combined sensible-latent heat storage matrix (CRAPH), with sensible matrix (SRAPH) and with latent heat storage matrix (LRAPH) were comparatively evaluated according to their thermal and economic performances. The temperature distributions of sensible and latent heat storage materials in the matrix exhibit different characteristics. The latent heat storage material that undergoes a phase change process during charging or discharging can greatly buffer the temperature swings of fluid and sensible heat storage material, especially under lower rotating speed conditions. Even if a small amount of latent heat storage materials were added to the sensible heat storage matrix, the efficiency of RAPH can be greatly improved.