While the method of lagrange was used to optimize the system , the optimized flow was gained . the flow was appended jet pump behind the first effect and the second effect . by this means , the second - degree vapor was improved and internal losing exergy caused by the difference in temperature of heat conduction and concentrated heat was reduced 采用拉格朗日乘子法对氯化铵回收的三效降膜蒸发系统进行经济优化，得出三效降膜蒸发系统优化流程，即采用在第一、二效后增加热泵和真空蒸发的方法，提高了二次蒸汽的品位能，减少了由于传热温差和浓缩热引起内部(火用)损。
In order to improve the utilization efficiency of energy and equipment , a general steady simulation model of complex cross - feed multi - effect evaporation was established for the purpose of in - depth research on rule of multi - effect evaporation . in this model , the energy - saving measures , including extra steam being led off to preheat material liquid , the condensation water flash and solution flash , were adopted , and the solid separation was also considered in the process of evaporation 为了提高多效蒸发系统能量与设备的利用效率以及深入研究多效蒸发过程的规律,建立了带有冷凝水闪蒸、溶液闪蒸和引出额外蒸汽预热原料液等节能措施并考虑蒸发过程有固相析出的复杂错流多效蒸发稳态模拟通用模型。
Hydraulic ejectors , made of cast iron or stainless steel , are widely used in vacuum and evaporation system to carry out vacuum evaporation , vacuum pumping , vacuum filtering , vacuum crystallizing , drying and deodorization etc . in the areas of sugar refinery , pharmaceutical , chemical , foodstuff , salt , monosodium glutamate , dairy , ferment , brewing , light industry and national defense 水力喷射器分铸铁和不锈钢两种材质，应用极为广泛，主要适用于真空与蒸发系统，进行真空蒸发、真空抽水、真空过滤、真空结晶、干燥、脱臭等工艺，是制糖、制药、化工、食品、制盐、味精、牛奶、发酵、酿造、轻工、国防部门广泛需要的设备。
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。
