The energy saving technology of countercurrent multi - effect evaporation for light alkali concentration 逆流多效蒸發淡堿濃縮工藝節能技術研究
The multi - effect evaporation system ca n ' t be designed in order that both total area of heat conduction and consumption of vapor were least 不可設計一個多效蒸發系統,使總傳熱面積和加熱蒸汽消耗量同時為最小,只能求得相對有效解。
A new design program for three - effect evaporation system of interleaving flow was educed . it provided a preferable base for the design of multi - effect evaporation system 本文編制了一套三效錯流蒸發系統設計計算程序,對于多效錯流蒸發系統的設計計算提供了較好的基礎。
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 為了提高多效蒸發系統能量與設備的利用效率以及深入研究多效蒸發過程的規律,建立了帶有冷凝水閃蒸、溶液閃蒸和引出額外蒸汽預熱原料液等節能措施并考慮蒸發過程有固相析出的復雜錯流多效蒸發穩態模擬通用模型。
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 該模型利用矩陣方程具有結構清晰和高度模塊化的特點,將復雜多效蒸發系統的物料及熱量衡算方程組以矩陣形式表達,通過保留或舍棄矩陣中特定功能模塊,模型就能代表有或無固相析出、有或無引出額外蒸汽預熱原料液、有或無冷凝水閃蒸、有或無溶液閃蒸等不同情況以及各種情況任意組合的并流、逆流、錯流多效蒸發過程,從而實現模型的通用性。
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 操作型模型分別以t _ 0 、 t _ k 、處理量f _ 0 、出料濃度x _ ( az )等不同控制變量為未知變量并采用矩陣法結合迭代法進行操作模擬計算;在操作模擬計算的基礎上,建立了復雜多效蒸發系統操作優化模型,該模型以濃縮成本最小為優化目標,以t _ k和f _ 0為決策變量,采用遺傳算法結合矩陣法求解。