Material balance and energy balance equations of complex multi - effect evaporation system were expressed in matrix equation , which has the advantages of clear structure and high modularization . by holding or omitting correlation block - matrix in matrix equation , matrix equation could be used to describe the difference of forward - feed , back - feed and cross - reed multi - evaporation system with or without solid separation , extra steam being led off to preheat material liquid , condensation water flash , or solution flash . the models include design and operation 该模型利用矩阵方程具有结构清晰和高度模块化的特点,将复杂多效蒸发系统的物料及热量衡算方程组以矩阵形式表达,通过保留或舍弃矩阵中特定功能模块,模型就能代表有或无固相析出、有或无引出额外蒸汽预热原料液、有或无冷凝水闪蒸、有或无溶液闪蒸等不同情况以及各种情况任意组合的并流、逆流、错流多效蒸发过程,从而实现模型的通用性。
The effective heat - transfer temperature difference ( t _ i ) of every effect of multi - effect evaporation subsystem and the preheat temperature rise ( t _ ( p , j ) ) of every level of multi - level preheat subsystem of the design model were distributed by equal heating area , equal heat - transfer temperature difference , and free proration methods . the simulation of design has been conducted by matrix method combined with iterative method . the free proration method transformed the decision variables from t _ i and t _ ( p , j ) with complex restriction into _ i 、 _ p , jwith the value range of 0 1 , and provided a simple and convenient method for optimum design 操作型模型分别以t _ 0 、 t _ k 、处理量f _ 0 、出料浓度x _ ( az )等不同控制变量为未知变量并采用矩阵法结合迭代法进行操作模拟计算;在操作模拟计算的基础上,建立了复杂多效蒸发系统操作优化模型,该模型以浓缩成本最小为优化目标,以t _ k和f _ 0为决策变量,采用遗传算法结合矩阵法求解。
