基于邻域-克隆选择学习算法的分馏装置负荷优化

在免疫克隆选择和人工免疫网络算法基础上,采用了Agent的思想,提出了一种邻域-克隆选择学习全局优化算法(N-Clonalg)。不同于其他人工免疫算法,N-Clonalg定义了网格化的邻域操作环境,其主要搜索算子有N-克隆选择、N-竞争和自学习算子,能有机结合全局与局部搜索,多峰测试函数表明能较好地克服克隆选择算法(Clonalg)的早熟及人工免疫网络算法(Opt-aiNet)收敛速度慢问题。分馏装置负荷优化实例应用表明,算法具有较好的最优解搜索性能,能较好地实现化工中的寻优问题。     

柴油加氢装置分馏系统的Aspen建模与优化

为了改进柴油加氢装置的生产操作,提高装置经济效益,满足今后改造的需要,文章利用Aspen流程模拟软件对装置的分馏部分的汽提塔和分馏塔进行建模和优化,通过模型模拟值和装置数据的对比,确定了该模型的准确性。在模型的基础上利用灵敏度分析功能找到该装置的可调节变量,对分馏部分进行多个优化点进行讨论并对装置进行了实际的优化。结果表明:增加汽提塔塔底蒸汽用量,可减少塔底油中硫化氢含量;通过调整重沸炉燃料气用量,控制分馏塔塔底温度,研究分馏塔塔底温度对石脑油收率和石脑油/柴油重叠度的影响。寻找一平衡点,增产石脑油或柴油。     

蒽醌法过氧化氢萃取塔板效率计算及改进研究

应用两相互不溶逆流萃取模型,对蒽醌法过氧化氢萃取塔板效率(Murphree级效率和总塔效率)和萃取过程进行计算,并与实验结果比较;对萃取塔板进行了改进研究。结果表明:萃取过程的模型计算结果与实验结果一致。与改前萃取塔板相比,改进后塔板Murphree级效率提高49%、总塔效率提高65%;在总板数44块、氧化效率7.0g/L时,可直接制备质量分数35%过氧化氢产品。     

催化裂化装置分馏塔的Aspen模拟优化

为了改进催化裂化装置的生产操作,提高经济效益,本文利用Aspen plus流程模拟软件对装置的分馏塔进行建模和优化,通过模型模拟值和装置数据的对比,验证了该模型的准确性。在模型的基础上利用灵敏度分析功能找到该装置的可调节变量,对分馏部分多个优化点进行讨论分析,通过对分馏塔顶部循环流量、第一中段流量和顶循返塔温度的调节,可以提高粗气油干点,减小汽油/柴油重叠度,最大限度的增产汽油。     

帽罩式气液并流接触塔板的板效率——传质池与混合池双池模型

对以VST为代表的帽罩式气液并流接触塔板的的板效率,提出了传质池与混合池定数双池模型,推导出液相Murphree板效率数学模型,用文献中的实验数据进行验算,所得计算值与实验值基本符合,并分析了各种因素对塔板效率的影响关系。     

催化裂化装置主分馏塔的过程模拟研究

综合现有相关文献的方法和模拟经验,采用Aspen Hysys 9.0对某石化220万吨/年催化裂化装置主分馏塔进行建模研究,逐步分析建模过程中的关键点。采用PR物性方法,采用Aspen Hysys的Petroleum Assay Manager功能建立组分列表和蒸馏数据,采用"反推合成法"进行进料表征,采用单个带冷凝器的精馏塔模型,脱过热段的人字板用两块塔板模拟。通过模型调整,综合对比全塔温度分布、产品蒸馏数据以及中段取热数据,使模拟结果与实际标定数据吻合。     

背包式反应器与精馏塔耦合合成醋酸甲酯的模拟

针对背包式反应器与精馏塔耦合过程循环流股多,模拟计算收敛难度大的缺点,在Aspen P lus的RadFrac模型中引入Murphree板效率,仅用一个精馏塔模型就描述了这个复杂耦合过程的模拟模型。在固定精馏塔塔板数的情况下,讨论了背包反应器个数和间隔位置、进料位置、回流比和催化剂量等因素对醋酸甲酯合成的影响。初步探索了反应能力和分离能力的匹配问题。模拟结果表明,当采用5个背包反应器,反应器之间间隔4块分离塔板的配置时,在适宜条件下醋酸总转化率可达到96.3%。     

溶剂油生产两塔分馏单元的建模与应用

本文以溶剂油生产装置的两塔分馏单元为研究对象,针对两塔分馏单元的实际情况,分析其生产工艺特点,如产品模式切换频繁、产品更新换代快、装置运行负荷变化幅度大等,在结合分馏单元实际生产数据的基础上,以化工工艺过程模拟软件Aspen HYSYS V7.1为工具,选用Aspen HYSYS V7.1软件提供的成熟的分馏塔严格计算模块,并对Peng-Robinson、Chao-Seader、Grayson Streed状态方程进行了模拟比较,根据比较结果选择Peng-Robinson为模型的状态方程,最终建立了两塔分馏单元的过程模型。通过对所建立的模型进行验证与应用,数据证明所建立的模型是可行、有效的,能够满足指导实际生产的需要,用于分析产品模式切换动态过程、预测产品性能、预测分馏塔运行状态、降低生产能耗等等,使企业实际生产做到低能耗、高效率,提高企业的市场竞争力。     

流程模拟在柴油加氢装置中的应用

应用PRO/Ⅱ软件,对某厂3. 0 Mt/a的柴油加氢装置分馏部分进行流程模拟,热力学方法采用BK10,得到了与装置实际工况相吻合的稳态模型。通过对模型进行综合分析,并与装置实际生产数据进行比较,取得了较好的吻合效果。同时通过调整脱硫化氢汽提塔的汽提蒸汽量及产品分馏塔塔顶回流比等优化手段来实现装置节能优化和经济效益的最大化,从而为装置优化操作、节能降耗和找生产瓶颈提供理论依据。     

柴油加氢改质装置的优化设计分析

针对2.3 Mt/a柴油加氢改质装置,对分馏系统及换热方案进行优化分析,分馏系统采用较优的汽提加分馏双塔流程,换热方案采用分馏塔底循环油与反应流出物进行换热,换热网络合理。并在多工况流程模拟的基础上对热高分温度、低分压力进行优化设计,从而降低了装置投资,减少了装置能耗。     

基于多智体免疫网络算法的精馏装置板效率估计(英文)

Based on the immune mechanics and multi-agent technology, a multi-agent artificial immune network (Maopt-aiNet) algorithm is introduced. Maopt-aiNet makes use of the agent ability of sensing and acting to overcome premature problem, and combines the global and local search in the searching process. The performance of the proposed method is examined with 6 benchmark problems and compared with other well-known intelligent algorithms. The experiments show that Maopt-aiNet outperforms the other algorithms in these benchmark functions. Furthermore, Maopt-aiNet is applied to determine the Murphree efficiency of distillation column and satisfactory results are obtained.     

Effect of two-pass trays on distillation efficiencies

Two important structural factors that affect distillation efficiencies, the outlet weir heigh and the liquid flowpath length, are investigated. Performance and efficiency data of an industrial scale i-butane/n-butane distillation column equipped with two-pass trays are used as a basis for the calculations. A mathematical development for a new method for predicting the numbers of vapor and liquid phase transfer units is given. This method together with some other NTU calculation methods is used to assess the effect of the outlet weir height on efficiencies. The effect of outlet weir height on the Murphree tray efficiencies is investigated using the observed point efficiencies and different point efficiency to the Murphree tray efficiency relation methods. The effect of varying liquid flowpath lengths on efficiencies is studied by calculating the Murphree tray efficiencies for one-pass and two-pass trays. The results obtained using the NTU calculation method presented in this study show that a certain outlet weir height point efficiency reaches its maximum. Most of the other methods give opposite results giving a minimum for point efficiency at a certain outlet weir length. The results also show that the Murphree tray efficiencies for one-pass trays are higher than for two-pass trays. Obviously, this is caused by the longer liquid flowpath length of one-pass trays. The Murphree tray efficiencies are also calculated for an industrial-scale MTBE purification column. The column is equipped with two-pass trays in the stripping section and with one-pass trays in the rectifying section. The Murphree tray efficiencies of one-pass trays are considerably higher than the two-pass tray Murphree tray efficiencies.     

PTA装置溶剂脱水塔模拟及塔板效率分析

精对苯二甲酸装置溶剂脱水塔在去除氧化反应生成水,保持整个氧化单元水含量稳定,减少醋酸消耗中起到核心作用。基于ASPEN PLUS流程模拟软件,以模型计算偏差最小为目标,通过调整板效率,实现溶剂脱水塔的模拟,为溶剂脱水塔的优化调整提供了基础。同时,分析主要参数之间的相关性,以及对各塔板成分板效率的影响,结果表明:塔负荷与塔压降之间存在线性相关;塔压降对夹带剂醋酸正丙酯的板效率影响较大,对水、对二甲苯、醋酸和醋酸甲酯的影响很小。     

Simulation and analysis of dehydration distillation column based on distillation mechanism integrated with neural network

In an industrial solvent dehydration distillation column (SDDC) model, the Murphree efficiency represents the separation ability of a distillation tray and the SDDC model’s performance depends on the value accuracy of the Murphree efficiency. Because there are many operation conditions having nonlinear effect on Murphree efficiency, it is difficult to determine its value. To develop a precise and robust SDDC model, a novel hybrid model combining distillation mechanism with neural network is proposed. In the SDDC hybrid model, the neural network is employed to model the nonlinear relationship between the operation conditions and Murphree efficiency, which is embedded into the SDDC mechanistic model. The results showed a good predicting and robust performance of the hybrid model under different operation conditions. Based on the hybrid model, the effect of the operation conditions on SDDC was analyzed to obtain some useful guiding rules for the SDDC operation.     

多组分物系精馏过程级效率的研究

提出一个适用于多组分理想或非理想物系以及伴随反应的精馏过程级效率的新定义式.该式克服了Murphree定义式当物系为非理想性很强的多组分时各组分的级效率值所表现的奇异性.本文还推导出计算级效率的方程,并用文献数据和作者所测得的反应精馏过程的实验数据验证了所得的理论方程.     

A SIMPLE APPLICATION OF MURPHREE TRAY EFFICIENCY TO SEPARATION PROCESSES

Vapor-liquid equilibrium is predicted by using the Soave modification of the Redlich-Kwong equation of state (EOSrpar;. The concept of equal fugacities is used to calculate the equilibrium constant, K₁ = y₁/x₀, then, it is shown how the Murphree tray efficiency can be applied on the liquid or the vapor phases to modify that constant. The derivatives needed are calculated numerically, and it is shown that for absorbers and distillation columns, Murphree tray efficiency applied this way can be used to simulate the actual number of stages

Murphree tray efficiency values can be specified for one, several or all of the components on any stages of a column

A dehydration example is shown, the dew point depression values of a mixture of water-gas, using a triethylene glycol solution for dehydration purposes, are calculated by incorporating the method into a process simulator program called PROSIM® and compared with the values reported in the literature.     

Modeling and Modernization of Tray Towers for Reactive Distillation Processes

The velocity, temperature, and concentration fields on a bubble tray were numerically modeled for a reactive distillation process using a two-dimensional mathematical model of momentum, mass, and heat transfer phenomena as a basis. The Murphree mass transfer efficiency matrix has been obtained. Some engineering solutions for modernizing an industrial plant for separating a ternary mixture with the possibility of increasing the initial mixture processing capacity by 25% and improving the efficiency of the reactive distillation process have been considered.     

A computer-controlled pilot-plant distillation unit and studies on multicomponent distillation

A pilot-plant unit for distillation studies consists of a tray column, an on-stream process analyzer and a process computer. The analyzer system is based upon a quadrupole mass spectrometer, and provides means for on-line concentration measurements of both liquid and vapor samples with multicomponent mixtures. A study of multicomponent plate efficiencies is presented. Experimental results with water/ethanol/n-butanol mixture show that the Murphree vapor phase efficiencies of the components differ markedly.     

计算传质法预测精馏塔效率(英文)

A computational mass transfer model is proposed for predicting the concentration profile and Murphree efficiency of sieve tray distillation column. The proposed model is based on using modified two equations formulation for closing the differential turbulent mass transfer equation with improvement by considering the vapor injected from the sieve hole to be three dimensional. The predicted concentration distributions by using proposed model were checked by experimental work conducted on a sieve tray simulator of 1.2 meters in diameter for de-sorbing the dissolved oxygen in the feed water by blowing air. The model predictions were confirmed by the ex-perimental measurement. The validation of the proposed model was further tested by comparing the simulated re-sult with the performance of an industrial scale sieve tray distillation column reported by Kunesh et al. for the strip-ping of toluene from its water solution. The predicted outlet concentration of each tray and the Murphree tray effi-ciencies under different operating conditions were in agreement with the published data. The simulated turbulent mass transfer diffusivity on each tray was within the range of the experimental result in the same sieve column re-ported by Cai et al. In addition, the prediction of the influence of sieve tray structure on the tray efficiency by using the proposed model was demonstrated.