Edinburgh Napier University

  The design and operation of a PV driven solar air heating system for drying woodchip is considered. For a given weight and moisture content of the woodchip sample, the effect of the dryer unit configuration on drying rate, that is, either operating with a thick or thin layer of woodchip, is discussed. Six alternative collector designs, based on absorber plate hole spacing and diameter, absorber material type, and the use of a collector cover are presented in relation to the ability of the complete system to dry the given sample. It is found that the system operating with the thin layer dryer in combination with the covered collector with aluminium absorber comprising 3mm holes at 3.0 cm pitch provides the highest annual yield of dried woodchip.