【作者】 孙晓静；

【导师】 王克峰；

【作者基本信息】 大连理工大学 ， 化学工程， 2005， 硕士

【摘要】 能量集成是以合理利用能量为目标的全过程系统综合问题,它最大程度利用工艺流股间的热交换,减少外加公用工程负荷,从总体上考虑过程中能量的供求关系以及过程结构、操作参数的调优处理,达到全过程系统能量的优化综合。 夹点技术和化工软件AspenPlus在化工能量集成中应用广泛,但夹点技术实现的优化目标是能耗最小,而不能实现费用最小的真正最优化。为此,本文提出了将AspenPlus的工程分析方法与遗传算法(Genetic Algorithm以下简称GA)及模式搜索(Pattern Search以下简称PS)的软计算相结合,以过程费用函数为优化目标的能量集成新方法,并以工业实例证明了该方法的有效性。本文主要研究内容如下: (1)利用以夹点技术为基础的针对大型复杂过程系统用能的诊断和调优策略,对全过程进行用能分析,分析判断出用能欠佳的流股及用能设备,根据“过程用能一致性”原则提出改变塔压或加设中间再沸器的改造方案; (2)应用AspenPlus的灵敏度分析得到精馏塔操作各参数之间的数学拟合方程,并在随机搜索算法——遗传算法(Genetic Algorithm)及模式搜索(Pattern Search)中设计费用函数,提出了将Aspen技术与随机搜索算法相结合的,以过程费用函数为优化目标的能量集成新方法; (3)通过提高塔压实现了利用塔顶冷凝热负荷作为塔底再沸器热源的能量集成,并应用于工业实例——气体分馏装置,证明了该集成方案的有效性。在优化过程中分别应用了由工程可行性分析角度出发的AspenPlus和软计算数学建模非线性随机搜索方法(GA,PS),两种方法均实现了能量集成,并取得了较一致的优化结果; (4)建立了以AspenPlus为平台的精馏模拟环境,采用塔顶冷凝热负荷作为中间再沸器热源的方案实现能量集成,应用于工业实例——干气制乙苯分离装置,取得了比较理想的优化结果。其中,详细分析了AspenPlus中各模块及物性方法的选用,以及中间再沸器热负荷和位置的确定。更多还原

【Abstract】 Energy integration is one of the whole process system synthesis problems which targets appropriate energy utilization; it maximizes the heat exchanges between streams and minimizes the hot and cold utilities required in the processes. Energy integration deals with the supply and demand relations, by adjusting process structure, operation parameters.Pinch Analysis technology for energy integration has seen widespread applications throughout the process industries, however it targets the energy cost minimization rather than total cost function minimization (including investment cost and utility cost). In this case , this paper presents a study on energy integration of chemical process, which is based onincorporated applications of Stochastic Methods--Genetic Algorithm (GA) and PatternSearch (PS), and the widely applied commercial industrial software- AspenPlus.Firstly, stream data can be generated automatically via the interface between AspenPlus and AspenPinch, and Heating and cooling curves can be drawn by AspenPinch, via which ways of debottlenecking for energy integration can be better guided.Secondly, Gain mathematical fitting equations of main distillation column parameters (such as the operation pressure, reflux ration, temperature at the top of the column, etc.) using sensitivity analysis of ApenPlus. Then Appropriate Cost Function of chemical process can be easily embedded in GA or PS which helps target the cost function minimization in chemical process. An example of petrochemical plant energy integration is presented, which showed the validity of this method.Besides, this paper offers two strategies for realizing energy integration of chemical processes which, are both based on the Consistancy Unit Energy Consumption: Raising column operation pressure so that consequently raises the temperature of condensers and reboilers; Using the condenser as a mid-reboiler for another column.更多还原