氧化铝生产多效蒸发器建模仿真

作为氧化铝生产过程的关键工序，多效蒸发工序的设备较多、操作复杂，蒸发过程涉及到的变量众多、变量之间的耦合关系很复杂，给现场操作带来了一定挑战。蒸发器蒸水量和汽水比(新蒸汽用量与蒸水量比值)是蒸发工序考核的重要指标，其数值大小直接影响到蒸发工序操作成本。尤其在蒸汽不足时，蒸发效果直接影响到母液浓度，甚至影响整个生产流程及产能，最终影响到企业的竞争力。调查发现，现场操作基本以经验为主，调整工艺参数未能到达预期目的，有时甚至出现相反效果，致使蒸发器潜能未能充分发挥，生产条件未能达到最优。基于物料衡算、能量衡算，借助流程模拟软件，搭建氧化铝生产逆流多效蒸发工艺等效物理模型，对拜尔法氧化铝生产多效蒸发工序工艺参数进行分析，探究不同工艺参数对蒸水量(汽耗)的影响规律，为蒸发工序实际操作提供理论指导，进而实现氧化铝生产节能、减排目的，助力氧化铝企业绿色低碳可持续发展。

Model and Simulation for Multi-effect Evaporator in Bayer Process

As one of the most important sections in Bayer process, the multi-effect evaporation process has more equipment and complex operation, and the evaporation process involves numerous variables, whose coupled relations are complicated, which brings certain challenges to the field operation. Water evaporating value and steam to water ratio (ratio of fresh steam to water evaporating value) are the important assessment indicators of evaporation process, which values directly affect the operational cost. Especially when the steam in insufficient, the evaporation effect directly affects the concentration of mother liquor, even affects the entire production process and capacity, and ultimately affects the competitiveness of the enterprise. In the real refinery, workers manage process parameters according to practice experience, which sometime cannot achieve expected goal and even arise reverse effect, restricting evaporators potential performance, and process parameters are not optimal. Based on material balance and energy balance, the equivalent physical modules of countercurrent multi-effect evaporation process for alumina production were modeled with the help of process simulation software, and the process parameters of the multi-effect evaporation process for alumina production by Bayer process were analyzed. The influences of different process parameters on the evaporation water amount (steam consumption) were explored to provide theoretical guidance for the actual operation of the evaporation process, which can achieve the purpose of energy saving and emission reduction in alumina production, and help the green and low-carbon sustainable development of alumina enterprises.