Energy Usage for Low Temperature Grain Drying with Optimized Management

Atechnique is presented to solve the control problem associated with minimizing the operating energy costs of a low temperature corn drying system considering predicted varying ambient weather conditions. The maximum effective total heat change of the grain mass was used in a modified critical path method of solving network flow problems to select the way of operating the controls. The effects of the different control strategies were determined from a nonequilibrium, empirical, low temperature, thin layer drying model that was developed to simulate drying and spoilage of corn in the deep bed. Substantial energy savings over continuous fan operation were obtained when the technique developed was used in five types of drying facilities for good, bad and typical drying years. Two other management schemes using relative humidity and time of day as the switching parameters also indicated considerable energy savings in drying the grain without exceding dry matter loss limits.