An innovative 'passive-solar' timber drying kiln: Progress Report II

This report details the technical progress in the design of an autonomous solar kiln for timber drying and covers the continued development of IoT-based monitoring and control systems, development of fan control system, and system validation through testing.The kiln’s key system components, including the lighting, fan control, and monitoring nodes have been successfully developed and test. The fan control system was proven functional, through a prototype test, a troubleshoot of the monitoring nodes system identified system restarts caused by hourly data uploads. Computational Fluid Dynamics (CFD) simulations indicate that continuous, derated fan operation is more effective for overall temperature increases than pulsed operation, and that the inclusion of all internal radiative surfaces was necessary for accurate simulation results, increasing CPU only marginally. Furthermore, a scale model experiment successfully validated the simulation model, demonstrating its capability to accurately predict the thermal behaviour of the solar receiving surface and internal air temperatures, thereby establishing a reliable tool for future full-scale kiln optimisation and design.