Thermal performance and economic analysis of an indirect solar dryer of wood integrated with packed-bed thermal energy storage system: A case study of solar thermal applications

Abstract

The present work is aimed at investigating the thermal performance and the economic feasibility of an indirect solar dryer of wood integrated with thermal energy storage system. The proposed dryer system is composed of a drying chamber, a solar air collector and a packed-bed energy storage (PBES) system. A new numerical model is developed for investigating the thermal performance of the dryer system and numerical simulations were performed using TRNSYS software. A comparative study between measured and predicted results shows a good agreement and the obtained maximal Relative Error (RE) for the drying time prediction is about 2.49%. Annual dynamic simulations were carried out under the new climatic zoning of Morocco and the effect of some design and operation parameters on wood drying kinetic is presented and discussed. Results obtained show that integrating one m³ of PBES into the dryer system leads to continue the wood drying process during a small part of the off-sunshine hours and to reduce the drying time by about 15%. The payback period of the dryer system is reduced by about 33% in Tangier site by using the storage system. Maximal amount of produced dried wood is obtained during the summer period for all Moroccan sites and the most suitable location of the dryer system is zone 6 with a payback period equal to 1.85 years.

Keywords:

• Solar dryer of wood
• thermal storage
• thermal performance
• economic analysis
• TRNSYS

Acknowledgments

The authors greatly acknowledge the financial support from the Moroccan National Center for Scientific and Technical Research (Ref. Number: 31UAE2016).

Declarations of interest

No potential conflict of interest was reported by the authors.