Grain drying optimisation at low temperatures

The optimisation of grain drying systems was studied through the dynamic programming technique focusing on the minimisation of the energy consumption, taking in account the conservation of the product quality and avoiding excessive humidity gradients in the bed at the end stages of drying. An algorithm was developed, where the input data were the initial conditions of the product and the climate data of the region. The operational conditions considered were: fan on or off, and different degrees of air heating (1 to 5 degrees C). The result obtained was an optimised management strategy for the operation of the dryer, specified for each stage of the process, in two situations: calculated from the mean climate data of ten years, and corrected day by day with up to date climate data.