Abstract: Because industrial drying is one of the most energy-intensive batch unit operations, a scheduling plan of multi-effect drying was studied. Based on the rate of drying curve, operation time in each effect of multi-effect drying process was designed to be the same. An optimal plan and scheduling of multi-effect drying model was established. Defining the number of effects and the drying time as the decision variables, the minimum annual cost model of the batch n-effect drying process could be expressed as a mixed-integer non-linear programming (MINLP)problem, which could be solved by the GAMS software. An example of slit drying process (effect from 1 to 5) was analyzed with the model. The results indicated that the 4-effect drying was the optimal, and it could save 26% of the cost each year compared to the 1-effect drying. Optimal Gantt chart of scheduled process was also presented. According to the Gantt chart, the least period and the optimal operation process could be determined. It indicated that the batch multi-effect drying process could achieve continuous production.

Key words: multi-effect drying, batch process, plan and scheduling, optimization, MINLP

摘要： 针对干燥过程是一个高能耗的间歇单元操作，对多效干燥过程进行了排产调度研究。根据干燥速率曲线，将各效干燥过程设计为等操作时间，建立了多效干燥过程排产调度的优化模型。以效数和干燥器干燥时间为决策变量，以年费用最小为目标表达为一个混合整数非线性规划（MINLP）的数学模型，利用GAMS进行求解。以淤泥1～5效干燥为算例进行了优化调度分析，结果表明：在4效时年费用最小；与1效干燥相比，在最优条件下年生产费用可节约26%。同时获得了最优排产调度的Gantt图，从而可以得出干燥设备的最小操作周期，据此对多效干燥过程进行排产，使间歇多效干燥过程可以实现连续化生产，对多效干燥的工业化具有一定的意义。

关键词: 多效干燥, 间歇过程, 排产调度, 优化, MINLP