Modelling and simulation of a hybrid solar-electrical dryer of wood integrated with latent heat thermal energy storage system

Abstract

The main objective of this study is to investigate numerically a novel design of an indirect hybrid solar-electrical dryer of wood integrated with latent heat thermal energy storage system. The studied wood dryer system is composed mainly of a drying chamber, a solar air collector, a thermal energy storage system with Phase Change Material (PCM) as storage medium and an electrical heater. Two numerical models for both drying chamber and thermal energy storage system are developed and validated with existing experimental data. These models are coupled with TRNSYS software standard library and a global model for the dryer system is presented. An optimization study of the thermal storage system is performed and the optimal amount of PCM and the optimal number of tubes were determined. The thermal performance of the developed dryer system is investigated under weather conditions of Tangier site in Morocco. Obtained results show that using the thermal storage system in the dryer system ensures a continuous wood drying process and the temperature of the drying chamber is higher than that of the ambient air by about 4–20 °C, all the night. Performance analysis of the dryer system shows that throughout the year, the drying time in the proposed dryer system with latent heat storage does not exceed 5 days. However, it varies between 7.5 days during summer and 12 days in winter in the case of the dryer without heat storage system.