【作者】 徐智迅；

【导师】 周国发；

【作者基本信息】 南昌大学 ， 化工过程机械， 2012， 硕士

【摘要】 在化工行业中,我国单位产值的能源消耗量比发达国家要高很多,其主要原因就在于分离过程的能耗远高于发达国家。蒸发操作即为分离过程,其耗能大,并伴随着二次蒸汽的产出,所以自上世纪70年代的能源危机以来,对蒸发操作中节能优化和有效控制的研究成为重中之重。本文基于Aspen Plus软件对蒸发系统进行了数值模拟研究。分别分析进口流量、各效压力和温度等参数的变化对蒸发性能的影响,在其他参数一定的条件下,模拟出操作参数变化对系统性能影响的变化规律。同时,建立了三种不同结构的三效蒸发系统模型,研究比较不同工况下每种工艺的能耗大小,得出带预热的多入口结构蒸发系统比基本蒸发系统节能约9.3%,而带预热的单入口结构蒸发系统比基本蒸发系统节能达到约12%。为了满足出口完成液浓度达到工艺要求,分别在不同体积分数的条件下对系统进行模拟,得出最佳体积分数值,基于此体积分数下对各效温度、压力参数进行优化,最终计算得出系统能耗最小时各参数的设定情况,为实际生产中蒸发系统的设计提供了一定参考。基于动力学模拟,本文以海水淡化多效蒸发过程为工业背景,对三效蒸发分离过程操作变量变化影响进行了灵敏度分析,明确了其主要控制参数,通过这些参数控制来实现对产品品质参数浓盐水的浓度和产水量的间接控制。通过控制效果和干扰影响的仿真模拟研究,证明了本文提出的控制结构和控制策略符合工艺控制要求,且具有良好的抗外界干扰能力,通过控制蒸发罐的TBT、压力和液位能精确有效的间接控制蒸发分离过程的浓度等过程生产品质指标。更多还原

【Abstract】 In the chemical industry, the energy consumption per unit of output in our country is much higher than in developed countries, the main reason is that the energy consumption of the separation process is far higher than the developed countries. The operation of evaporation, which is energy intensive together with the secondary steam production, is the separation process, so since the energy crisis in the1970s, it is the top priority that is the research on the energy optimizing and effective control of the operation of evaporation.In this paper, the evaporation system is simulated based on the Aspen Plus software. Results the influence of flow rate, temperature, pressures of the evaporating performance, under the condition of the constant other parameters, the change rules on the influence of the operation parameters changes are simulated. At the same time, it sets up three system models of three effect evaporation with different structure, and contrast the energy consumption of each configuration in the different working conditions, this paper concluded that multiple entry preheated systems can be energy-efficient than the evaporation system in general about9.3%, and the single entry preheated could save12%. In order to meet the technological requirements of the consistence of accomplished liquid, the paper obtain the best value of volume fraction through the simulation model with different concentrations, then each effect temperature and pressure parameter has been optimized, finally each parameter is worked out when the energy consumption is minima, the results provides some references for the evaporation system designed in practical production.Based on the dynamics simulation, in the industry background of seawater desalination multi-effect evaporation process, a sensitivity analysis the effects of various operating variables on three effect evaporation separation processes were made in this paper, and the main control parameters are definite, through these parameters, it could realize that the indirect control of product quality parameters of the concentrated brine concentration and the water production are controlled. Through the simulation research of the control effect and the interference, it is proved that the control structure and control strategy meet the requirement of technology control, and it has the good function of anti-interference, the indirect control of the quality index on evaporation of the separation process concentration under the controlled the evaporated pot TBT, pressure and liquid level is accurate and effective.更多还原