Simulation and energy efficiency analysis of desiccant wheel systems for drying processes

In drying processes it is necessary to appropriately control air humidity and temperature in order to enhance water evaporation from product surface. The aim of this work is to investigate several HVAC configurations for product drying based on desiccant wheels, in order to find systems which reach high primary energy savings through the appropriate integration of refrigerating machines, adsorption wheels and cogenerative engines. Simulations are carried out for different values of sensible to latent ambient load ratio and the effect of ambient and outside air conditions is evaluated for each configuration. It is shown that primary energy savings can reach 70–80% compared to the reference technology based on a cooling coil. With respect to works available in literature, the results of this study keep a general approach and they can be used as a simple tool for preliminary assessment in a wide range of applications.

► Several HVAC systems for product drying based on desiccant wheels are investigated.
► The sensible to latent ambient load ratio influences the choice of the best system.
► Energy savings can reach 80% compared to the technology based on a cooling coil.
► Simulation results can be used for preliminary assessment in many applications.