Energy and quality analysis of forced convection air-energy assisted solar timber drying

Abstract

Discontinuities due to weather conditions and daylight affect solar drying, so to address that, a working mechanism of air energy-assisted solar drying was developed in this study. An air-energy assisted solar dryer was used to dry timber, from a green average moisture content of 183%–11.3% in 161.5 h, where the moisture diffusion coefficient ranged from 1.28 ×10-10 m2/s to 6.41 ×10-9 m2/s. The effective solar radiation intensity during drying ranged from 221.3 to 750.3 W/m2. The overall drying efficiency was 30.7%, and the effective solar heat supply ratio was 58.5%. The specific moisture extraction rate and specific energy consumption were measured within a range of 0.32–3.0 kg/kWh and 924 - 11390 kJ/kg, respectively. The average power consumption per m3 of wood volume was 254.2 kW h/m3. The results showed that the energy-assisted solar dryer was suitable for a condition with low radiation and various weather conditions.