内部热耦合精馏塔的初步设计(I) 模型化和操作分析

引　言将热量从精馏段传到提馏段来实现节能是精馏过程节能的一种有效方法 ,即二次回流和蒸发[1](ＳＲＶ) .内部热耦合精馏塔 (ＩＴＣＤＩＣ)的热耦合机理仍是ＳＲＶ方法 ,但去掉了再沸器和冷凝器 ,具有较大的节能潜力 .它的研究只有近 1 0年的历史[2 ,3],目前 ,还没有见到详细的操作分析和设计优化的文献报道 ,只有一些较为相关的文献[4 ,5 ].本文对理想热耦合精馏塔进行了建模和操作分析 .1　模型化图 1是ＩＴＣＤＩＣ的示意图 .精馏段和提馏段被分为两个塔 .热耦合通过两段之间的热交换器来实现 .为了提供传热必须的推动力 ,精馏段将在较…     

激光散射法测定草酸结晶介稳区

引　言草酸 (ＯＡ)作为重要有机化工原料广泛应用于医药、染料中间体 ,稀有金属的提炼 ,以及原子能工业 .其典型生产方法有 :甲酸钠脱氢法、淀粉硝酸氧化法、乙二醇氧化法和丙烯氧化法[1,2 ].本研究采用由ＣＯ气相偶联制草酸酯 (ＤＥＯＡ)再水解制取ＯＡ .此工艺先进 ,无污染 .ＯＡ晶体的粒度分布 (ＣＳＤ)要控制在 2～ 3ｍｍ均匀粒度范围内 ,结晶介稳区宽度的数据对产品的ＣＳＤ影响很大 .近年来许多研究者提出了不少测定介稳区的方法[3,4].大致分为 3类 :第 1类是间接法 ,由测定折射率、电导率、浊度、溶液体积与温度的变化等来测定介稳区…     

位于Alberta的大型石化公司零排污水处理系统的开车和运行

道化学加拿大有限责任公司在Ａｌｂｅｒｔａ的一套大型石化联合体含有一大型冷却塔、许多蒸汽发生器、一台四床脱盐器、冷凝液精制器和其它一些水处理设备,通过努力实现了零排污。文章中作者回顾了该系统的工艺设计、讨论了水系统的运行情况。(参5,图4)(李绍全供稿)循环冷却水系统微生物诱导腐蚀(ＭＩＣ)的监测———ＲＯＤＮＥＹＤＯＮＬＡＮ,ＲＡＹＭＯＮＤＪＳＩＭＭＥＮ,ＡＬＡＮＬＳＭＩＴＨ,ＣＨＲＩＳＴＯＰＨＥＲＬＷＩＡＴＲ,ＩＷＣ—96—69　　通过对微生物腐蚀的三种诊断特征:(1)检查与ＭＩＣ的有关的细菌;(2)检查微生物代谢产物…     

多种有机氯农药残留量的测定方法

目前 ,世界各国对水果、蔬菜中有机氯农药残留量都作了严格的限量要求。有机氯类农药急性毒性虽小 ,但性质稳定 ,容易造成残留。水果、蔬菜中六六六、ＤＤＴ或其它单个残留有机氯农药的测定 ,国内已建立了方法 ,但对多种 (13种以上 )有机氯农药残留量检测的研究甚少。采用混合溶剂提取 ,柱层析技术净化方式结合ＧＣ -ＥＣＤ方法成功地分离、检测了水果、蔬菜中 16种农药残留量 ,该方法简便快速 ,准确灵敏。1　实验部分1 1　主要仪器和试剂仪器 :ＨＰ6 890ＧＣ仪配ＥＣＤ检测器 ;ＨＰ3396色谱数据处理机 ;ＨＩＴＡＣＨＩＣＴ6Ｄ高速离心机 ;…     

国际水会议(IWC)论文摘要

冷却水系统的严重有机污染 :成功的消除实例和技术途径———ＣＬＡＵＤＩＯＬ .Ｖ .ＤａＣＯＳＴＡ ,等 ＩＷＣ - 2 0 0 1- 11　　来自于换热器的有机污染导致了冷却水侧面出现了严重的污垢沉积。采取了几项措施 ,包括使用新型分散剂和杀菌剂以及监测手段和过滤设备 ,取得了明显效果且成本较低ＭＩＣ指数 (模型 )的评述和比较———ＲＩＣＨＡＲＤＷ .ＬＵＴＥＹ ,等 .ＩＷＣ - 2 0 0 1- 0 4　　在冷却水和相关的工艺水系统中 ,当微生物、生态学和冶金学因素以特定的组合存在于特定的微观环境中时 ,就会发生ＭＩＣ(微生物引起的腐蚀 )。本…     

我厂合成氨装置电动机的控制系统简介

我厂合成氨装置电动机的控制系统简介中原化肥厂王鸿义中原化肥厂主要生产过程的调节和指示，采用集散型ＤＣＳ系统（数字控制系统ＤＩＧＩＴＡＬＣＯＮＴＲＯＬＳＹＳＴＥＭ），而联锁保护和程序控制，则采用ＰＬＣ系统（可编程逻辑控制器ＰＲＯＧＲＡＭＬＯＧＩＣＣＯＮ...     

国际会讯

20 0 1年国际会议(1)焚化及热处理工艺国际大会 [ＩｎｔｅｒｎａｔｉｏｎａｌＣｏｎｆｅｒ ｅｎｃｅｏｎＩｎｃｉｎｅｒａｔｉｏｎａｎｄＴｈｅｒｍａｌＴｒｅａｔｍｅｎｔＴｅｃｈｎｏｌｏｇｉｅｓ (ＩＴ3) ]于 2 0 0 1年 5月 14～ 18日在美国宾夕法尼亚州费城举行。联系地址 :ＴｉｎａＨａｄｄｅｄ ,Ｃｏｎｆｅｒｅｎｃｅａｓｓｉｓｔａｎｔ (949/ 82 4 70 6 6 ;ｆａｘ :949/ 82 4 190 0 ;ｅ ｍａｉｌ:ｔａｈａｄｄａｄ @ｕｃｉ.ｅｄｕ .;ｈｔｔｐ :/ /ｗｗｗ .ｅｈｓ.ｕｃｉ.ｅｄｕ .)。(2 )ＩＣＭＦ 2 0 0 1,第 4届国际多相流大会 (ＩＣ…     

国际水会议(IWC)论文摘要

全有机化学处理 ,特别是高磷酸盐和高钙容忍度处理方案的开发———ＳＥＲＧＩＯＣＡＳＴＲＯ ,ＩＮＳＴＲＯ ,ＩＮＳＴＩＴＵＴＯＭＥＸＩ ＣＡＮＯＤＥＬＰＥＴＲＯＬＥＯ(ＩＷＰ) ,ＭＥＸＩＣＯ ,Ｄ .Ｆ .,ＭＥＸＩＣＯ .ＩＷＣ— 1999— 49　　作者评述了一种高磷酸盐含量的“全有机”配方的开发。该配方可在比较温和的 ｐＨ下运行 ,运行安全可靠 ,腐蚀率在 0 .0 2 5ｍｍ/ａ以下 ,配方组成是环境友好的。Ｃｏｎｅｍａｕｇｈ电厂凝结水精处理器的升级———ＧＥＲＡＬＤＧＡＬＬ ,ＧＰＵ/ＧＥＮＣＯ ,ＮＥＷＦＬＯＲＥＮＣＥ ,ＰＡ .ＩＷ…     

抽提腐植酸后的风化煤残渣对Cr^6＋,Zn^2＋离子的吸附研究

抽提腐植酸后的风化煤残渣对Ｃｒ６＋、Ｚｎ２＋离子的吸附研究ＳＴＵＯＹＯＮＡＤＳＯＲＰＴＩＯＮＯＦＣｒ６＋、Ｚｎ２＋ＴＯＲＥＳＩＤＵＥＯＦＬＥＯＮＡＲＤＩＴＥＥＸＴＲＡＣＴＥＤＨＵＭＩＣＡＣＩＤ崔强宁晓军甄捷１前言工业污水的处理与人类的生存相关。随着工...     

SOPDT模型不确定性界及其在内模控制器设计中的应用

引　言内模控制 (ＩＭＣ)是一种在化工过程中有广泛应用前景的鲁棒控制 ,由于这一先进控制能保证系统的鲁棒稳定性和鲁棒性能 ,从而在过程控制界引起了极大的兴趣[1～ 8] .鲁棒控制器设计的必要条件之一 ,是首先要有实际过程的不确定信息 ,即模型 (或过程 )的不确定性界[7] .对于在过程控制中经常采用的一阶加纯滞后过程 (ＦＯＰＤＴ) ,其模型不确定性界的计算方法已有报道[5～ 7,9] .然而 ,过程控制中常常会遇到二阶加纯滞后过程 (ＳＯＰＤＴ) ,有时更高阶的过程采用ＦＯＰＤＴ模型来近似往往不能保证闭环系统的性能 ,需要采用ＳＯＰＤＴ模…     

内部热耦合精馏塔的初步设计(II) 控制分析和参数优化

Based on the previous design model, degrees of freedom analysis and transient analysis are carried out. A PID control model is proposed. The results show that ITCDIC is a self-regulating process, and could be operated smoothly with two PID controllers; the steady state design could be disassociate with the dynamic design. An optimization model of ITCDIC design parameters is derived, which can directly achieve the optimal design parameters providing the maximum energy savings and the product quality simultaneously. Benzene-toluene system is studied as an illustrative example.     

Thermodynamic analysis, simulationand optimization on energy savings of ideal internal thermally coupleddistillation columns

Internal thermally coupled distillation columns (ITCDIC) are the frontier of distillation energy saving research. In this paper, a novel energy saving model of ideal ITCDIC and a simulation algorithm are presented,upon which a series of comparative studies on energy savings with conventional distillation columns are carried out. Furthermore, we present an optimization model of ideal ITCDIC, which can be used to achieve the maximum energy saving and find the optimal design parameters directly. The binary system of benzene-toluene is adopted for the illustrative example of simulation and optimization. The results show that the maximum energy saving of ITCDIC is 52.25% (compared with energy consumption of conventional distillation under the minimum reflux ratio operation); the optimal design parameters are obtained, where the rectifying section pressure and the feed thermal condition are Pr=0.3006 MPa and q=0.5107 respectively.     

Adaptive Robust Generic Model Control of High‐Purity Internal Thermally Coupled Distillation Column

The internal thermally coupled distillation column (ITCDIC) is a frontier in energy‐saving distillation research. The process inside a high‐purity ITCDIC is of great nonlinear dynamics, which trouble the conventional control schemes. A multivariable adaptive robust generic model control (ARGMC) is presented to solve the difficulties, where an ARX model is derived and a recursive least squares estimation (RLSE) method is introduced. The benzene/toluene system is studied as an illustrative example. The results of ARGMC are compared with the robust generic model control (RGMC) and traditional PID control in detail. The performances in both servo control and regulatory control confirm the accuracy and validity of ARGMC for the high‐purity ITCDIC process.     

Adaptive generalised predictive control of high purity internal thermally coupled distillation column

Internal thermally coupled distillation column (ITCDIC) is a frontier in the energy‐saving distillation researches. One of the bottlenecks to prevent the column from being commercialised is the difficulty in control design due to the high sensitivity to disturbances, strong asymmetric nonlinearity and inverse response especially under high purity. An adaptive multivariable generalised predictive control (AM‐GPC) strategy of ITCDIC process is proposed to solve the difficulties in high purity. The simulation results of AM‐GPC are compared with single input and single output GPC (S‐GPC), multivariable GPC (M‐GPC), modified IMC (M‐IMC) and traditional PID control in detail. The performances confirm the accuracy and validity of AM‐GPC for the high‐purity ITCDIC process. © 2011 Canadian Society for Chemical Engineering     

基于一般模型控制的高纯内部热耦合精馏策略

内部热耦合精馏塔（ITCDIC）是精馏节能控制的一个前沿。本文提出了一种基于一般模型控制（GMC）的内部热耦合精馏塔的先控策略,以解决导致传统线性控制策略难以得到较好控制效果的高纯下内部热耦合精馏塔的非线性。以苯-甲苯物系作为研究实例,对所提出的高纯ITCDIC控制策略进行了详细研究。设定值改变和过程扰动下的控制品质表明了所提出的高纯ITCDIC的GMC控制策略的切实有效性。     

Nonlinear wave modeling and dynamic analysis of internal thermally coupled distillation columns

Internal thermally coupled distillation column (ITCDIC) is a frontier in the energy saving distillation research. It is well known for the complex dynamics, which challenge the establishment of an excellent reduced model for further control strategy design greatly. In this article, a physical approach of the ITCDIC process based on nonlinear wave theory is explored, where it is first discovered that traditional wave theory in conventional distillation columns (CDIC) could not be directly applied in ITCDIC, due to: First, the internal thermal coupling results in mole flow rates varying evidently over each stage, which not only makes the wave modeling of the wave phenomenon in ITCDIC more difficult but also makes wave dynamics greatly different between ITCDIC and CDIC; Second, an interesting wave phenomenon of ITCDIC is discovered that waves located in the rectifying section and stripping section travel under opposite tendencies when the steady state is disturbed by the step change of thermal condition q, one sharpens and the other is likely to spread synchronously, it means the movement of wave profiles in ITCDIC could not be simply described by shock wave velocity, which is usually used in wave modeling of CDIC; more seriously, shapes of the self‐sharpening wave profiles in ITCDIC change obviously during the traveling processes, which further reveals that shape influence on wave velocity has to be considered in the wave modeling of ITCDIC. A rigorous wave velocity and a natural wave velocity are derived, respectively, based on which, the detailed analyses of traveling wave characteristics are carried out. A novel wave velocity, based on the profile trial function which has been well developed by Marquardt, is further derived to consider the obvious change of profile shape. And a completed nonlinear wave model of ITCDIC is thereby established by combining the proposed wave velocity with thermal coupling relations and material balance relations. The benzene‐toluene system is illustrated as an example, where component concentration prediction and distinct dynamic characteristics are carried out in detail based on the proposed nonlinear wave models. The research results reveal the accuracy and validity of the proposed nonlinear wave model of ITCDIC. © 2011 American Institute of Chemical Engineers AIChE J, 2012     

Investigating Control Schemes for an Ideal Thermally Coupled Distillation Column (ITCDIC)

The control schemes of an ITCDIC are addressed. A modified IMC scheme (M‐IMC) is proposed to overcome model/plant mismatch of the Internal Model Control scheme (IMC). Predictive PID control (P‐PID) and Adaptive Predictive control (AP‐PID) schemes are also presented to improve effectively the response speed of the multi‐loop PID control (M‐PID) and eliminate its residual error. A detailed comparative investigation on the above five control schemes was performed. Simulation results demonstrate all the schemes are able to keep two end products within their specifications. M‐IMC is the best one with the fastest response speed. AP‐PID is the second choice since it is better at dealing with sudden set‐point transitions and complex external disturbances than P‐PID. M‐PID cannot compete with AP‐PID and P‐PID due to its slow servo response speed and large residual error. IMC ranks last as it is extremely sensitive to changes in the operating conditions.     

内部热耦合精馏塔基于非理想物系的最优评价

Internal thermally coupled distillation column(ITCDIC) is a frontier in energy saving distillation research. In this paper, the optimal assessment on the energy saving and the operating cost for ITCDIC of nonideal mixture is explored. An evaluating method is proposed, and the pertinent optimization model is then derived. The ethanol-water system is studied as an illustrative example. The optimization results show that the maximum energy saving in ITCDIC process is about 35% and the maximum operating cost saving in ITCDIC process is about 30%,as compared with a conventional distillation column(CDIC) under the minimum reflux ratio operating; the optimal operating pressure of the rectifying section is found to be around 0.25 MPa; the effects of the feed composition,operating pressure and the heat transfer rate on operation are also found and analyzed. It is revealed that ITCDIC process possesses high energy saving potential and promising economical prospect.     

基于内部热耦合精馏塔非线性wave模型的高纯控制

首先建立内部热耦合精馏塔（ITCDIC）的非线性波动降阶模型,并将非线性波动理论（wave）应用到ITCDIC控制问题中,实现一般模型控制（GMC）方案.与传统控制方案相比,基于波动理论的一般模型控制（waveGMC）不再采用ITCDIC的近似线性模型,更好地解决了高纯控制过程中的非线性问题,通过对波形的速度和位置控制能够在短时间内使系统达到稳定.苯-甲苯物系的实例研究表明,ITCDIC波动模型在高纯控制过程中能够精确反映ITCDIC的动态特征,waveGMC控制方案较传统控制方案更加稳定可靠.