多效精馏回收DMF工艺的研究

针对传统的DMF回收工艺的高能耗,本文提出多效精馏回收DMF的双塔、三塔和四塔工艺流程.利用ASPEN PLUS 化工模拟软件中的RADFRAC模块和NRTL热力学计算模型,系统模拟了多效顺流、多效逆流回收工艺,以处理不同浓度的DMF废水工况.并以能耗最低为目标函数、各塔顶废水蒸出量为决策变量,确定各种回收工艺的最佳条件(包括塔压分布).利用ASPEN PLUS软件中的流体力学计算模块,算出各塔的设备参数,包括各附属冷换设备的面积.并以多效精馏与单塔精馏总费用的相对值最低为目标,确定的最佳DMF回收分离方案为三塔逆流精馏工艺,模拟计算出该工艺各效最佳工艺操作条件.研究结果表明,处理浓度分别为10%、20%和25%的DMF废水时,与单塔精馏工艺相比,三塔逆流精馏工艺节能分别为78%、79%和87%.     

复杂平流多效精馏系统能量集成模型及过程模拟

为了更合理利用能量,将平流多效精馏系统中各效塔底产品、第1效至第n-1效塔顶产品及首效再沸器中加热生蒸汽的冷凝液用于预热原料液,建立由多效精馏及多级预热2个子系统构成的复杂平流多效精馏系统的能量集成模型。用于模拟具有切点系统的高度非理想溶液的平流多效精馏过程,用迭代法结合矩阵法求解。结果表明:用系统余热预热原料液可节省加热生蒸汽消耗量25%～35%,是1种非常有效的节能措施;各效精馏塔回流比及再沸器的有效传热温差、首效塔底再沸器中加热生蒸汽压力(或温度)、末效塔顶压力(或温度)、原料液的预热温度等参数,对平流多效精馏系统的操作费用及设备费用影响很大。     

化工精馏高效节能技术开发及应用

高效节能精馏流程通过优化构造流程结构,合理利用精馏塔顶蒸汽的冷凝潜热,可以大幅度降低精馏过程的能耗.本文系统研究各种节能型精馏流程,重点分析3种热泵精馏、4种多效精馏和4种热偶精馏的流程特点,建立节能型精馏流程优化模拟及分析系统,将模拟优化计算的结果与普通精馏流程对比.结果表明,热泵精馏节能率可达80%以上,多效精馏40%以上,热偶精馏20%以上,为工业化应用提供设计依据和友好的平台.     

热集成变压精馏分离乙二胺水溶液的模拟

基于乙二胺和水物系共沸组成随压力变化显著的特点,采用变压精馏工艺分离乙二胺和水物系:为了降低变压精馏工艺的能耗,提出了热集成变压精馏新工艺。使用ChemCAD软件,对变压精馏工艺和热集成变压精馏工艺进行了模拟。结果表明:采用变压精馏工艺和热集成变压精馏工艺都能实现乙二胺和水共沸物的高纯度分离,每个产品的纯度都可以达到99%;与变压精馏工艺相比,采用热集成变压精馏工艺,加热公用工程可节能33.91%;冷却公用工程可以节能34.94%。     

热集成精馏序列综合的MINLP模型

将夹点分析法应用于热集成精馏序列综合的换热网络设计中,建立一个以分离序列和操作压力为变量的混合整数非线性规划模型,然后运用改进模拟退火算法进行求解,避免了以换热网络结构作为独立变量,提高了用随机搜索方法获得最优解的可能性,同时提高了计算速度。该模型既允许一个塔的冷凝器和多个塔的再沸器进行热匹配,以及一个塔的再沸器和多个塔的冷凝器进行热匹配,还允许一个塔的冷凝器和再沸器同时与其它塔进行热匹配,使可回收利用的能量大大增加。算例的计算结果表明该方法是求解多组分热集成精馏序列综合问题的有效方法。     

基于AFSA-BP算法的模糊PID控制器在DMF回收系统中的应用

针对DMF(N,N-二甲基甲酰胺)回收系统存在时滞性、难以确定温度控制的数学模型等问题,提出了用人工鱼群算法(AFSA)优化BP神经网络,设计了基于AFSA-BP算法的模糊PID控制器。对模糊BP神经网络各层之间的连接权值以及隶属函数相关参数进行训练,克服了反向传播过程中最速下降法易陷入局部最优解的缺点,能够得到PID参数的最优解。研究结果表明,采用AFSA-BP算法的迭代次数少并且能接近给定值,在DMF回收系统中应用相关的PID参数,精馏塔的温度保持稳定,液位高度保持动态稳定且误差更小。     

热集成变压精馏分离甲缩醛和甲醇工艺模拟及优化

在分析甲缩醛和甲醇二元体系共沸特性基础上,提出热集成变压精馏分离甲缩醛和甲醇共沸体系的工艺方法。利用AspenPlus软件对该分离过程进行模拟计算,采用NRTL方程作为物性计算模型,其二元交互作用参数由汽液相平衡数据回归,详细分析了加压塔和常压塔的理论板数、进料位置和回流比对分离过程的影响,并进行能耗比较。结果表明,采用热集成变压精馏分离工艺,可很好地实现甲缩醛与甲醇的分离,较佳的操作条件为:加压塔操作压力1.0MPa,理论板数28,第18块板进料,回流比3.2,塔釜甲缩醛含量可达99.9%;常压塔操作压力0.1 MPa,理论板数24,第14块板进料,回流比2.6,塔釜甲醇含量可达99.5%。与常规变压精馏相比较,热集成变压精馏可节省能耗达35.5%,为共沸物分离过程的设计和改造提供依据。     

多装置热集成的热出料温度优化研究

本文采用(火用)用经济学模型来描述跨装置热集成问题,该模型以集成的换热网络和长距离换热匹配费用最小为目标.通过适当提高中间物流进料温度,不仪可避免该物流"在上游装置冷却,下游装置重复加热"的能量利用现状,还可节省一组换热设备投资.若允许物流跨装置热匹配,长距离换热匹配的管线投资会增加,但可获得全局最大能量优化.本模型通...     

煤制乙炔的热集成设计和动态性能分析

等离子裂解煤制乙炔工艺是一种处于试验阶段的新型煤化工路线。系统的节能、平稳运行对新工艺的经济性和可行性至关重要。本文基于夹点技术对煤制乙炔全流程进行了用能分析和诊断,得出了最优的能量利用目标;在考虑实际约束的情况下提出2套换热方案。进一步,利用路径法得出两套换热方案的传递函数,由此建立了动态仿真模型,进而得到2套换热方案对扰动的动态响应特性;在对传递函数进行分析的基础上,发现影响换热网络动态性能的公用工程位置和单个换热器换热充分度2个因素。结果表明,方案1和方案2均具有较好的动态性能,能够保障节能方案的平稳运行。     

城市污水处理厂自动控制系统的设计与实现

城市污水处理厂自动控制系统是集控制功能、管理功能和数据处理功能于一体的DCS控制系统。在遵守行业规范，满足行业特点要求基础上，论证了城市污水处理厂自动控制系统的结构设计要点和功能设计要点及实现方法，并给出了一个设计应用实例。     

1种新型废液处理过程仿真培训系统的开发

使用典型的通用监控和数据采集组态软件作为图形用户界面开发平台,应用动态补偿建模法建立过程动态工况模型,提出了1种新的基于单台计算机的智能控制(industrial personal computer and intelligent process controller, IPC)仿真模式,开发了1种废液处理过程操作培训仿真器。通过设计1种动态链接库函数,经过监控组态软件的数据库将动态模型计算程序和仿真图形用户界面相连,成功地实现了整套仿真软件的集成开发。废液处理过程操作培训实践表明,该仿真器具有良好性能,能较好地满足废液处理过程操作培训需要,对提高操作技能,减少污水排放具有良好效果。     

An integrated method for predicting damage and residual tensile strength of composite laminates under low velocity impact

An integrated approach is presented to analyze the whole process of damage initiation and development for composite laminates under impact loading as well as tensile loading after impact using the 3D progressive damage theory. The real impact damage status of composite laminates is employed to analyze the residual tensile strength instead of the artificial premises adopted by traditional methods. This integrated approach can not only improve the prediction accuracy of the ultimate strength but also avoid large numbers of experiments for obtaining the impact damage parameters. A parametric modeling program package based on the analytical method has been developed.     

A fuzzy neural network approach for online fault detection in waste water treatment process

In this paper, an effective strategy for fault detection of sludge volume index (SVI) sensor is proposed and tested on an experimental hardware setup in waste water treatment process (WWTP). The main objective of this fault detection strategy is to design a system which consists of the online sensors, the SVI predicting plant and fault diagnosis method. The SVI predicting plant is designed utilizing a fuzzy neural network (FNN), which is trained by a historical set of data collected during fault-free operation of WWTP. The fault diagnosis method, based on the difference between the measured concentration values and FNN predictions, allows a quick revealing of the faults. Then this proposed fault detection method is applied to a real WWTP and compared with other approaches. Experimental results show that the proposed fault detection strategy can obtain the fault signals of the SVI sensor online.     

间位TDA回收工艺优化的研究

向含有间位TDA的焦油加入邻位TDA,通过闪蒸,间位TDA减少,邻位增加,而焦油浓度不变,部分间位得到回收.通过模拟计算,找出温度、邻位配比对回收效果的影响规律,发现邻位配比越大则回收率越高,而温度对回收效果的影响很小.以年效益为目标,设备和操作费用同时考虑,以邻位配比为变量,求得它们之间的关系曲线,最后得到较优的邻位配比范围2-3,当取2时,年经济效益为536万元.     

Synergetic fusion of energy optimization and waste heat reutilization using nature-inspired algorithms: a case study of Kraft recovery process

Neural Computing and Applications - This article presents a novel energy management strategy of multiple-stage evaporator (MSE). The maximum efficiency of MSE is achieved by optimum selection of...     

The effects of strength testing schedules on muscle strength recovery following static work

In order to measure the recovery of muscle strength after static contractions, strength tests must be performed at various times recovery. This is shown to be an invasive procedure, particularly at typically-recommended schedules of one measurement every 30 s or every 60 s, as the measurement interferes with the recovery process. A predictive equation is given to correct recovery data for this invasiveness.     

Satellite remote sensing of waste water reservoirs

SPOT multi-spectral images of nearly 100 water reservoirs were analysed. The image analysis was supported by ground measurements which included water sampling and detailed laboratory analysis of the water constituents and concentration. The analysed reservoirs covered a wide range, from open drinking water reservoirs to polluted hypertrophic ones. Classification of reservoirs by their water quality is achieved by the study of the spectral distribution of the reflected solar radiation, taking into account the atmospheric effects. The techniques included chromatic coordinates analysis and principal component analysis. An optical model of the volume reflectance of the water body was constructed, based on the radiative transfer equation which includes the scattering properties of the main water constituents. Numerical simulations, based on the model, support the experimental findings regarding the reservoir c1assilication according to water quality and composition.