- 作者: Chang, T.N.; Ma, Y.H.
- 中文摘要: --
- 英文摘要: This work applies time-optimal control algorithm with bounds on control and state variables to a hybrid microwave and radiant freeze dryer system. We employ a general unsteady state mathematical model with time variant transport and dielectric properties to describe the dryer system, then solve the model as a stagewise problem. The controllable variables are microwave power, radiator temperature, water partial pressure and air pressure with constraints set to avoid scorching, melting and gas breakdown. All control variables remain constant during each stage. With a high nonlinearity and moving boundary characteristics of this problem, the direct search method yields the optimal strategy. Different case studies illustrate the algorithm and their results suggest that a hybrid microwave and radiant freeze drying system can substantially reduce the dehydration time. Moreover, the case studies demonstrate that the algorithm can be used to devise an optimal policy for limited freeze drying.
- 中文關鍵字: 控制陣列法; 冷凍乾燥; 最適控制策略; 微波
- 英文關鍵字: Control Algorithm; Freeze Drying; Dehydration; Optimal Control Strategy; Microwave