Temperature-Variable Optimal Drying Process of Heat Pump for Cabbage Seeds

The principle of heat and mass transfer in temperature-variable drying process of the heat pump for cabbage seeds was studied.On the basis of unsteady drying dynamics equation,the advantages in the rate of moisture diffusion during the temperature-variable drying process were analyzed.Intermittent ratio was introduced,and through the simulation of the moisture diffusion process under temperature-variable drying methods,the energy consumption,uniformity of moisture diffusion and seed vitality were discussed.It was considered that intermittent drying method was better than continuous con-stant-temperature drying,and triangular and sinusoidal change of cyclic drying method of temperature-variable drying,be-cause intermittent drying method of temperature-variable drying did less damage to enzyme activity and seed vitality.Opti-mal intermittent ratio for over-all properties was 1/3 in the temperature-variable drying process.