多变量预测控制软件包APC-Hiecon在液化气回收装置上的应用

针对扬子石化公司芳烃厂液化气回收装置脱丁烷塔存在的进料波动大,操作变量多,关联性强等控制难点,使用多变量预测控制软件包APC－Hiecon设计多变量预测控制器来实现对脱丁烷塔的平稳控制并提高分离效果,取得了很好的控制效果和显著的经济效益。     

二甲苯精馏装置先进控制与节能优化应用

以预测控制和实时优化为代表的先进控制技术可以保证产品质量、提高产率、降低能耗,已经越来越多地应用到石油化工装置上。二甲苯精馏是芳烃生产中的重要单元,具有很大的控制难度,且塔底重沸炉耗能巨大,具有较高的节能空间。针对二甲苯精馏单元的精馏塔和塔底重沸炉在操作和控制中存在的一些问题,根据机理与实际装置数据,建立了该单元的状态空间模型,基于多变量状态反馈预测控制技术开发了该单元的先进控制系统,使装置运行平稳性得到显著改善,提高了精馏塔的分离效果,通过优化促进了装置节能减排。该先进控制系统在两个实际装置应用中都取得了很好的控制和优化效果。     

PTA溶剂脱水塔先进控制与在线优化

从PTA溶剂脱水塔的工艺操作特点出发，运用RMPCT多变量预测控制软件，建立以塔顶与塔釜组分为被控变量，以塔釜温度回路设定值和回流量为操纵变量的溶剂脱水塔先进控制与在线优化系统．稳定溶剂脱水塔的操作，综合降低塔的酸耗和蒸汽消耗，取得满意的控制效果。     

重整C+9重芳烃高效分离技术研究

中国石化某分公司45万t/a芳烃抽提装置投产后,由于上游原料调整,造成二甲苯塔塔底组分终馏点一直较高,汽油调和组分发生变化,导致全厂汽油干点超标,为此,拟将C⁺₉重芳烃送至歧化与烷基转移单元生产二甲苯。目前,C⁺₉重芳烃无法满足进料要求,因此提出新增重芳烃塔、二甲苯塔新增侧线和二甲苯塔改造为分壁精馏塔3种解决方案。通过对C⁺₉重芳烃分离进行模拟,对比分离能耗和产品质量,确定二甲苯塔改造为分壁精馏塔作为C⁺₉重芳烃高效分离方案,同时进行单因变量优化研究。结果表明,回流比为4.4、隔板位置为隔板上方39层塔板处、侧线采出位置为32层塔板、气相分配比为1.024、液相分配比为0.313、进料位置为44层塔板时,C⁺₉重芳烃确定满足歧化与烷基转移单元进料要求,同时分离能耗最低。     

重芳烃塔停运期间国Ⅵ汽油生产对策

某石化公司二甲苯装置停工检修,1#芳烃抽提装置随后停工,新建2#芳烃抽提装置开工运行,承担起重整生成油的分馏和芳烃抽提任务.正常生产期间,二甲苯装置内设置的重芳烃塔将C9+芳烃分离为C9芳烃和重芳烃两股物料,C9芳烃用于调合汽油,重芳烃经1#催化分馏塔分离后进入柴油池.二甲苯装置停工后,重芳烃塔停运,2#芳烃抽提装置生产的C9+芳烃无法进一步分离.而C9+芳烃终馏点相对较高,调合汽油使用比例受限,国Ⅵ汽油生产困难.针对此难题,生产运行上通过组织S_zorb装置回炼化工轻油,提高汽油调合组分整体占比等手段,成功将C9+芳烃资源全部调合进入汽油池,并有效降低了柴汽比,提升了经济效益.     

PRO／Ⅱ模拟软件在重芳烃分离装置开车中的应用

通过应用PRO/Ⅱ模拟软件,模拟锦州石化精细化工有限公司重芳烃分离装置的预分馏塔、偏三甲苯塔、富集均三塔,与实际生产数据进行比较分析后,指导装置开车,取得了较好的效果。     

重芳烃分离装置开车运行总结

以含有30％以上的偏三甲苯的重芳烃为原料成功采用两塔分离的方法用规整填料进行工业化分离同分异构体。经过技术改造后装置的处理量、偏三甲苯的收率及装置其它各项指标均达到了设计要求，取得了令人满意的效果。     

氯乙烯精馏过程的先进控制系统

针对氯乙烯精馏过程存在的控制难点，使用多变量预测控制软件包APC-Hiecon设计了两个多变量预测控制器，并在低沸塔和高沸塔上应用，大大提高了生产操作平稳度和氯乙烯单体的纯度，取得良好的控制效果和显的经济效益。     

重芳烃分离装置开车运行总结

以含有30％以上的偏三甲苯的重芳烃为原料成功采用两塔分离的方法用规整填料进行工业化分离同分异构体。经过技术改造后装置的处理量、偏三甲苯的收率及装置其它各项指标均达到了设计要求，取得了令人满意的效果。     

隔壁塔在芳烃生产预分离中的应用及模拟

芳烃的传统生产过程具有流程长,循环物流多,原料预处理能耗大,污染严重等特点。传统预处理具有设备投资高,能耗大,萃取剂用量多等缺点。采用隔壁塔对芳烃生产原料重整汽油进行预分离的方案,能耗低,绿色化,经济性强。对传统的分离序列进行了详尽的模拟,得出了各种方案的具体能耗对比。对该结构中的隔壁塔的塔板数、回流比、侧线采出流量等进行了单塔模型稳态模拟优化。将隔壁塔的能耗与传统分离序列进行对比,最高可节省能耗45.7%。     

Kaibel分壁精馏塔分离芳烃的稳态和动态模拟

Kaibel分壁精馏塔(Kaibel divided-wall column,KDWC)可在一个塔内实现四组分混合物的高纯度分离。本文以分离苯、甲苯、二甲苯和均三甲苯为研究对象,建立了KDWC严格稳态模型,获得了优化的塔体结构。通过研究KDWC分离17组进料组成的基础上,获得了KDWC的稳态分离的初步规律:实现KDWC的高纯度分离,既需要通过分液比控制预分馏段顶部馏出气相中的二甲苯含量,又需要通过分气比控制预分馏底部馏出液相中甲苯含量;两个侧线的组成中,重组分杂质的含量要远多于轻组分杂质的含量;中间组分甲苯在预分馏段仍有返混。随后,在Aspen Dynamic环境下建立了KDWC的组分控制模型,控制结果表明该模型可以应对±10%的流量和进料组成波动,但二甲苯产品纯度会出现少量偏差。     

自动重质油组分分离装置的研制

介绍一种用于测定原油及渣油组分的自动重质油组分分离的装置,该自动重质油组分分离装置按照SH/T0509-2010标准,采用洗脱色谱柱法测量原油及渣油中各组分的含量。应用视觉识别技术和计算机控制,实现原油及渣油组分分离过程中溶剂自动计量、溶剂自动注入色谱层析柱,分离组分自动收集,从而实现原油及渣油组分分离自动操作,提高工作效率和数据检测的准确性,避免有机溶剂对操作者产生危害及环境污染。     

An Analytical Study of Separation Efficiency on the Enrichment of Heavy Water in Double-Flow Thermal-Diffusion Columns with Flow-Rate Fraction Variations

Considerable improvement in heavy water separation efficiency in a thermal diffusion column is obtainable by inserting an impermeable sheet or permeable barrier in parallel to divide an open duct into two subchannels for double-flow operations. The analytical results developed and investigated using an orthogonal expansion technique are represented graphically and compared with that in a Clusius-Dickel column of the same size. The impermeable-sheet or permeable-barrier location effect on heavy water separation efficiency enhancement is also discussed.     

An Analytical Study of Separation Efficiency on the Enrichment of Heavy Water in Double-Flow Thermal-Diffusion Columns with Flow-Rate Fraction Variations

Considerable improvement in heavy water separation efficiency in a thermal diffusion column is obtainable by inserting an impermeable sheet or permeable barrier in parallel to divide an open duct into two subchannels for double-flow operations. The analytical results developed and investigated using an orthogonal expansion technique are represented graphically and compared with that in a Clusius-Dickel column of the same size. The impermeable-sheet or permeable-barrier location effect on heavy water separation efficiency enhancement is also discussed.     

乙烯精馏塔异常工况在线侦测与控制

精馏塔是化工过程经常用到的一种分离设备,操作条件不当,易使精馏塔进入异常工况.正常工况时,出料温度随回流量增大而降低,模型增益为负;回流量继续增大,导致板效率下降,出料温度开始上升,模型增益变为正,精馏塔进入异常工况.针对此情况提出一种基于最小二乘法的乙烯精馏塔模型增益在线辨识方法,在线实时辨识出模型增益符号,根据辨识结果,判断乙烯精馏塔是否进入异常工况.建立正常与异常工况的乙烯精馏塔控制系统,根据模型增益辨识结果,由负反馈原理确定正常与异常工况中控制器正反作用,使得回流量和出料温度均控制在正常工况允许范围内,保证乙烯精馏塔在正常工况工作,实现乙烯精馏塔正常与异常工况控制.     

Enrichment of heavy water in flat-plate thermal diffusion columns inclined for improved performance

The optimum angles of inclination for maximum separation, maximum production rate and minimum column length in a flat-plate thermal-diffusion column for enrichment of heavy water have been determined. Essential improvement in performance is obtainable if the column is tilted at the optimum angle, instead of being placed vertically, so that the convection strength can be properly reduced and controlled, resulting in suppressing the undesirable remixing effect while still preserving the desirable cascading effect. Accordingly, considerable saving in fixed and operating charges can be achieved, particularly for lower production rate operations, or for smaller degree of separation.     

ENRICHMENT OF HEAVY WATER BY THERMAL DIFFUSION

Equations of the best wire angle of inclination for the maximum separation, maximum output and minimum column height for enrichment of heavy water in a concentric-tube wired thermal diffusion column have been derived. Considerable improvements in performance were obtained by employing the wired column instead of using the open column (without wire). It was also found that the wire inclination for maximum separation is also the wire inclination required to obtain the maximum production rate, or minimum column height, for a specified degree of separation.     

全回热反应蒸馏塔的动态特性研究

摘要全回热反应蒸馏塔的反应操作和分离操作过程具有特殊的欠阻尼特性，而通过严格的再沸器液位控制可以使欠阻尼效果基本消除。以A和B反应生成C来说明了理想全回热反应蒸馏塔的这种动态特性。     

The Enrichment of Heavy Water in a Continuous-Type Inclined Thermal Diffusion Column

Abstract

Equations of the best angle of inclination and the maximum separation for the enrichment of heavy water in a continuous-type inclined thermal diffusion column have been derived. Considerable improvement in separation was obtained by employing the inclined column instead of using the Clusius-Dickel column.     

Optimal operation and tracking control of vapor-recompressed batch distillation

Vapor recompressed batch distillation (VRBD) is an energy-integrated configuration which works on the principle of a heat pump. Operation of such a column is challenging due to unsteady, nonlinear dynamics and strong interplay between separation and energy efficiency. In this paper, a two-step approach is proposed for optimal operation and control of such a column. Initially, an openloop optimal operation policy is generated for maximization of an overall performance index using offline optimization. To this end, three performance indices are proposed to capture interplay between separation and energy efficiency. Subsequently, a model-based output feedback controller is designed to track this optimal performance trajectory. The effectiveness of the proposed approach is demonstrated using a benzene-toluene separation case study wherein it is shown that the proposed approach helps to achieve optimal operation in the presence of operational disturbances.