The power consumption of an air energy heat pump dryer running 20 hours is 1500 kwh, which generates 12900000 kcal and meets the requirement of heat-drying grain products. Such capacity, taking the Paddy rice as an example, could dry 24% moisture of 40000 kilos of grain and could get 36400 kilos of dried grain with 15% moisture which fits the standards for storage or for subsequent rice milling procedure.