热集成复杂精馏流程综合的随机最优化方法

This paper addresses the application of stochastic optimization approaches to the synthesis of heat integrated complex distillation system, which is characterized by large-scale combinatorial feature. Conventional and complex columns, thermally coupled (linked) side strippers and side rectifiers as well as heat integration between the different columns axe simultaneously considered. The problem is formulated as an MINLP (mixed-integer nonlinear programming) problem. A simulated annealing algorithm is proposed to deal with the MINLP problem and a shortcut method is applied to evaluate all required design paxameters as well as the total cost function. Two illustrating examples are presented.     

基于乙醇压缩的超重力热泵精馏热集成系统性能分析

将超重力精馏塔、单螺杆压缩机与新型热泵工艺技术创新性地相结合,提出超重力热泵精馏的概念。设计并搭建一套处理量为300 kg·h^-1的超重力热泵精馏热集成系统。以乙醇-水溶液为研究对象,使用单螺杆压缩机直接压缩乙醇蒸气。通过对超重力精馏塔不同转动频率的全回流实验和工业条件下系统的不同进料位置、不同回流比实验的研究,综合分析系统各影响参数的变化情况、节能特性和经济效益。结果表明,f_HG在40 Hz下运转时系统性能最佳;进料位置下移或增加回流比,都可提高y_D;如果仅从y_D值大小考虑,F_L03位置最佳;相比于低浓度乙醇-水溶液,处理高浓度优势更大;系统节能及经济效益显著,可为超重力热泵精馏在乙醇精馏的工艺流程选择、设计和应用方面提供理论指导。     

基于MVR热泵精馏的混合醇热集成分离工艺

机械蒸汽再压缩(MVR)热泵技术是把低品位的蒸汽通过压缩转变为高品位的蒸汽,循环用于热源的供热以减少能耗。而热集成技术则是合理的匹配冷热物流的换热,以提高物流的有效能利用率。鉴于精馏过程的高能耗和低热力学效率,本文以四元混合醇的分离为研究对象,把基于MVR热泵技术的热集成精馏工艺应用于该体系的分离,提出并研究了该体系带热集成与不带热集成各种MVR精馏工艺;以能耗和年总费用(TAC)为评价指标,采用Aspen Plus 软件对各分离工艺进行模拟与优化,确定各分离工艺的操作参数与设备参数。研究结果表明,与常规顺序分离工艺相比,MVR精馏工艺节约能耗50%以上,节约年总费用约61%。带热集成MVR精馏工艺与不带热集成MVR精馏工艺相比,在能耗和年总费用方面,优势相当,但前者热力学效率提高了约9.5%。     

热集成复杂精馏系统综合的研究

将夹点分析法应用于热集成复杂精馏系统综合的换热网络设计中,避免了以换热网络结构作为独立变量,建立了一个以预分馏塔组分回收率、回流比及操作压力为连续变量,以分离序列和热耦合方式为离散变量的混合整数非线性规划(MINLP)模型。该模型用改进的模拟退火算法求解,可同时得到优化的流程结构和操作参数。对多个五组分混合物分离问题进行了求解,并对不同优化方案的优化结果及其经济性作了比较和分析,结果表明采用热集成复杂精馏塔流程可以显著地降低系统的总费用,还表明该方法是求解热集成复杂精馏系统综合问题的有效方法。     

用于热集成精馏序列综合的改进模拟退火算法

提出一个用于多组分热集成精馏系统综合问题的改进模拟退火算法.将优化问题表示为混合整数非线性规划（MINLP）问题,将算法设计同研究问题的特征相结合,运用本文方法可在同一退火策略下实现流程结构和操作参数的同步优化,并能达到计算精度和计算速度的更好均衡.通过对大规模算例（产品数≥10）的计算表明,该方法对求解此类问题非常有效.     

TCS-S热偶精馏过程的优化设计

建立了TCS－S热偶精馏过程优化设计的数学模型，给出非精晰分割精馏塔最小回流比的求解方法，并给出简捷计算和严格计算的求解过程，编制了计算机程序。用苯－甲苯－乙苯物系为例进行考核计算，与普通塔的两个分离序列进行比较，节能效果十分显著。     

具有热集成和水集成的甲醇精馏新工艺及其模拟

提出了一种新的三塔精馏工艺用于合成甲醇的精制过程.在采用差压双效精馏实现系统内的热集成方案中,新工艺从加压精馏塔进料板上部的侧线采出中等甲醇浓度的物料作为常压精馏塔的进料,有效地平衡了两塔的分离负荷,进一步降低了双效精馏的总能耗,同时,将预精馏塔产生的盐碱类物质浓缩分离到加压塔底采出,使常压塔底出料为高纯度软水,将其循环复用为预塔萃取水,实现了系统内的工艺软水集成,不但降低了新鲜工艺软水的消耗,而且还减少了系统的废水排放量.运用计算机稳态模拟方法对传统的两塔工艺、现有的三塔双效精馏工艺和本文提出的新工艺进行了对比研究,研究结果表明：新工艺可以比两塔工艺节能49.2%,节水38.0%;比现有三塔工艺节能24.7%,节水38.0%.     

分割式热泵精馏流程的优化设计及运行调优

从系统能量平衡的角度,提出了适合于分割式热泵精馏优化设计和运行调优的系统参数———压缩机进气量,建立了以年总费用最小为目标函数的优化设计数学模型和以年操作费用最小为目标函数的优化运行数学模型。以酒精精馏为例,利用Aspenplus模拟软件对此流程进行了优化计算。与常规精馏相比,此流程节能效果和经济效益非常显著。文中还分析了优化结果的运行调优问题。     

热泵精馏与常规精馏的热力学分析比较

以实际运行装置的丙烯精馏塔为例,采用PROII 9.4软件对丙烯—丙烷分离过程中常规精馏和热泵精馏分别进行模拟,通过分析模拟结果,对比两种精馏方式的公用工程消耗、能耗及其经济性。     

热泵精馏与常规精馏的热力学分析比较

以实际运行装置的丙烯精馏塔为例,采用PROⅡ 9.4软件对丙烯—丙烷分离过程中常规精馏和热泵精馏分别进行模拟,通过分析模拟结果,对比两种精馏方式的公用工程消耗、能耗及其经济性.     

热泵精馏技术进展介绍

简要介绍了热泵精馏技术在国内外的发展情况,并对精馏技术的发展进行了讨论。     

压缩式热泵精馏中的工质选择

热泵精馏是一项高效节能技术。本文分析了压缩式热泵精馏中不同类型工质应用的特点,比较了它们的实际适用条件,这埘推广热泵精馏的工业应用有一定的指导意义。     

Split Heat Pump Distillation Based on Two-Stage Compression for Separating an Acetone-Water Mixture

There is a constant concentration zone for acetone-water mixtures, and the average relative volatility of the two components in the constant concentration zone is only 1.41, so the energy consumption of the conventional distillation process is high. Two kinds of split mechanical vapor recompression (MVR) heat pump distillation processes, i.e., single-stage and two-stage compression processes, were proposed to separate acetone-water mixtures. The thermodynamic data of the mixture were calculated and modules of Aspen Plus were used to simulate the distillation column and steam compressor. Taking the minimum total annual cost as the objective function, the conventional MVR and the two split MVR heat pump distillation processes were simulated and optimized. Compared with the conventional process, the MVR heat pump distillation process had greater economic advantages, and the split heat pump distillation (SHPD) with two-stage compression was superior to the other MVR heat pump distillation processes.     

Optimal Design and Optimal Operation of Separate Heat Pump Distillation

For a distillation system, in which relative volatility is large in low composition range and small in high composition range, using separate heat pump distillation (SHPD) can markedly save energy. In this paper, vapour flow rate to compressor is proposed as a parameter for system optimization, from the viewpoint of system energy balance. This parameter can be used for both optimal design and optimal operation of SHPD. Mathematical models for optimal design and optimal operation are formulated to minimize total annual cost and annual operating cost respectively. Optimal design of SHPD is performed and evaluated through process simulation, for a typical case study for the distillation of ethanol‐water system. The results show that SHPD has notable energy saving and economic benefit when compared with conventional distillation. Optimal operation of SHPD is also evaluated for changes in feed composition which is an operating variable.     

热泵精馏的控制研究

通过对精馏塔的系统特性进行分析,确定了适宜的控制方案,采用稳态模拟技术确定了灵敏板,并进行稳态闭环测试,在此基础上确定了闭式热泵精馏系统的控制方案.文中运用动态模拟技术对确定的热泵精馏控制系统的动态特性进行分析.结果表明,当系统出现扰动时,本文提出的热泵精馏控制方案能够使系统快速达到新的稳态,方案可行,且具有较强的抗扰动能力.     

Synthesis of Heat Integrated Complex Distillation Systems via Stochastic Optimization Approaches

This paper addresses the application of stochastic optimization approaches to the synthesis of heat integrated complex distillation system, which is characterized by large-scale combinatorial feature. Conventional and complex columns, thermally coupled (linked) side strippers and side rectifiers as well as heat integration between the different columns are simultaneously considered. The problem is formulated as an MINLP (mixed-integer nonlinear programming) problem. A simulated annealing algorithm is proposed to deal with the MINLP problem and a shortcut method is applied to evaluate all required design parameters as well as the total cost function. Two illustrating examples are presented.     

压缩式热泵在醋酸丁酯酯化工艺中的应用探讨

本文对压缩式热泵在醋酸丁酯酯化工艺中的应用进行的探讨,分别就系统的热力性能和经济性进行了分析。计算表明,使用热泵可提高系统经济性,节能效果显著。     

常压塔回流取热流程的讨论

根据一套500万t/a常减压蒸馏装置的数据,采用ASPEN PLUS软件对目前常减压蒸馏装置设计中采用的3种常压塔回流取热流程进行了模拟计算,并从产品分离精度、对换热网络终温的影响等方面进行了对比.对比结果认为流程1和流程3产品的分离精度比较好,流程2的换热网络终温较高、但产品的分离精度和常压塔的操作弹性较差.     

热泵在乙烯精馏工艺中的运用

常规精馏塔需从塔顶冷凝器取出热量,从塔釜再沸器加入热量,其消耗的能量为精馏塔的主要操作费用。热泵利用机械能或电能将低温位热能提高到高温位热能,在精馏中将塔顶气相加压冷凝后作为塔底再沸器的热源,特别是在乙烯装置乙烯精馏中运用热泵,将乙烯冷剂的循环和乙烯精馏结合为一体,利用乙烯冰机将开式热泵用在乙烯精馏中,可节约能耗,降低生产成本。