About ThisManualAbout This ManualTheAspenPlus User Guide consists of three volumes that provide step-by-stepinstructions for using Aspen Plusto build and use a process simulation modelVolume1describes theAspenPlus user interfaceand explains howtoperformthe basic tasks for creating and running simulations. Topics include:Creating a simulation modelDefining theflowsheetEntering the required information, such as components, streams and physicalpropertydataRunning the simulationExamining resultsVolume 2 contains procedures for using additional Aspen Plus capabilities:ConvergenceSensitivityDesignspecificationsOptimizationProperty analysisData regressionVolume3contains informationabout:Pressure relief calculationsStream librariesWorkingwithotherWindowsprogramsTheAspenPlusActivexautomation interfaceAspen PlusUser GuideVersion 10.1-0
Aspen PlusUser Guide i Version 10.1-0 About This Manual About This Manual The Aspen Plus User Guide consists of three volumes that provide step-by-step instructions for using Aspen Plus® to build and use a process simulation model. Volume 1 describes the Aspen Plus user interface and explains how to perform the basic tasks for creating and running simulations. Topics include: • Creating a simulation model • Defining the flowsheet • Entering the required information, such as components, streams and physical property data • Running the simulation • Examining results Volume 2 contains procedures for using additional Aspen Plus capabilities: • Convergence • Sensitivity • Design specifications • Optimization • Property analysis • Data regression Volume 3 contains information about: • Pressure relief calculations • Stream libraries • Working with other Windows™ programs • The Aspen Plus ActiveX® automation interface
About ThisManualFor More InformationOnline HelpAspen Plus has a complete system of online help andcontext-sensitive prompts.The help system contains both context-sensitive helpand reference information.Formore information about using Aspen Plus help,seethe AspenPlus User Guide, Chapter 3.Aspen Plus Getting Started Building and Running a Process Model Thistutorialincludes severalhands-onsessionstofamiliarizeyouwithAspenPlus.The guide takes you step-by-step to learn the full power and scope of Aspen Plus.Aspen Plus Getting Started Modeling Processes with Electrolytes Thistutorial includes several hands-on sessions to familiarize you with simulatingelectrolytesystemswithAspenPlus.Aspen Plus Getting Started Modeling Petroleum Processes This tutorialincludes several hands-on sessions to familiarize you with simulating petroleumprocesses with Aspen Plus.AspenPlus Getting Started Customizing Unit Operation Models Thistutorial includes several hands-on sessions to familiarize you with thecustomization of unit operation models with Aspen Plus.Aspen Plus User Guide The three-volume Aspen Plus User Guide providesstep-by-step procedures for developing and using an Aspen Plus processsimulation model. The guide is task-oriented to help you accomplish theengineering work you need to do,using the powerful capabilities of Aspen Plus.AspenPlusreferencemanual seriesAspenPlus referencemanualsprovidedetailed technical reference information.These manuals include backgroundinformation abouttheunit operationmodels and thephysical properties methodsand models available in Aspen Plus,tables of Aspen Plus databank parameters,group contribution method functional groups,and a widerangeof otherreferenceinformation.Theset comprises:UnitOperationModelsPhysicalPropertyMethodsand ModelsPhysical PropertyDataUserModelsSystem ManagementSystem AdministrationSummary File ToolkitAspenPlus application examples A suite of sample online Aspen Plussimulations illustrating specific processes is delivered with Aspen Plus.iiAspen Plus User GuideVersion 10.1-0
ii Aspen Plus User Guide Version 10.1-0 About This Manual For More Information Online Help Aspen Plus has a complete system of online help and context-sensitive prompts. The help system contains both context-sensitive help and reference information. For more information about using Aspen Plus help, see the Aspen Plus User Guide, Chapter 3. Aspen Plus Getting Started Building and Running a Process Model This tutorial includes several hands-on sessions to familiarize you with Aspen Plus. The guide takes you step-by-step to learn the full power and scope of Aspen Plus. Aspen Plus Getting Started Modeling Processes with Electrolytes This tutorial includes several hands-on sessions to familiarize you with simulating electrolyte systems with Aspen Plus. Aspen Plus Getting Started Modeling Petroleum Processes This tutorial includes several hands-on sessions to familiarize you with simulating petroleum processes with Aspen Plus. Aspen Plus Getting Started Customizing Unit Operation Models This tutorial includes several hands-on sessions to familiarize you with the customization of unit operation models with Aspen Plus. Aspen Plus User Guide The three-volume Aspen Plus User Guide provides step-by-step procedures for developing and using an Aspen Plus process simulation model. The guide is task-oriented to help you accomplish the engineering work you need to do, using the powerful capabilities of Aspen Plus. Aspen Plus reference manual series Aspen Plus reference manuals provide detailed technical reference information. These manuals include background information about the unit operation models and the physical properties methods and models available in Aspen Plus, tables of Aspen Plus databank parameters, group contribution method functional groups, and a wide range of other reference information. The set comprises: • Unit Operation Models • Physical Property Methods and Models • Physical Property Data • User Models • System Management • System Administration • Summary File Toolkit Aspen Plus application examples A suite of sample online Aspen Plus simulations illustrating specific processes is delivered with Aspen Plus
About ThisManualAspenPlus InstallationGuidesTheseguides provideinstructions onplatform and network installation of Aspen Plus.The set comprises:AspenPlusInstallationGuideforWindowsAspenPlus Installation GuideforOpenVMSAspenPlus InstallationGuideforUNIXTheAspenPlusmanualsaredeliveredinAdobeportabledocumentformat(PDF)on theAspenPlusDocumentation CDTechnical SupportWorld Wide Web For additional information about AspenTech products andservices, check the AspenTech World Wide Web home page on the Internet at:http://www.aspentech.com/Technical resources To obtain in-depth technical support information on theInternet,visittheTechnical Supporthomepage.Registerat:http://www.aspentech.com/ts/Approximately three days after registering, you will receive a confirmation e-mailand you will then be able to access this information.The most current Hotline contact information is listed.Other informationincludes:Frequently asked questionsProducttraining coursesTechnicaltipsAspenPlusUserGuideiliVersion 10.1-0
Aspen PlusUser Guide iii Version 10.1-0 About This Manual Aspen Plus Installation Guides These guides provide instructions on platform and network installation of Aspen Plus. The set comprises: • Aspen Plus Installation Guide for Windows • Aspen Plus Installation Guide for OpenVMS • Aspen Plus Installation Guide for UNIX The Aspen Plus manuals are delivered in Adobe portable document format (PDF) on the Aspen Plus Documentation CD. Technical Support World Wide Web For additional information about AspenTech products and services, check the AspenTech World Wide Web home page on the Internet at: http://www.aspentech.com/ Technical resources To obtain in-depth technical support information on the Internet, visit the Technical Support homepage. Register at: http://www.aspentech.com/ts/ Approximately three days after registering, you will receive a confirmation e-mail and you will then be able to access this information. The most current Hotline contact information is listed. Other information includes: • Frequently asked questions • Product training courses • Technical tips
About ThisManualAspenTech HotlineIf you need help from an AspenTech Customer Supportengineer, contact our Hotline for any of the following locations:If you are located in:Phone NumberFax NumberE-Mail AddressNorth America & the+1-617/949-1021+1-617/949-1724support@aspentech.comCaribbean+1-888/996-7001(oll ree)South America(Argentina office)+54-11/4393-5308+54-11/4394-8621tecnoba@aspentech.com(Brazil office)+55-11/5506-0756+55-11/5506-0567tecnosp@aspentech.comEurope, Gulf Region, Africaatesupport@aspentech.com+32-2/724-0100(Brussels office)+32-2/705-4034(UK ofice)+44-1223/312220+44-1223/366980Japan+81-3/3262-1743+81-3/3262-1744atjsupport@aspentech.comAsia & Australiaatasupport@aspentech.com(Hong Kong office)+85-2/2838-6077+85-2/2833-5642(Korea office)+82-2/761-5800+82-2/761-5803+X&ivAspen Plus User GuideVersion 10.1-0
iv Aspen Plus User Guide Version 10.1-0 About This Manual AspenTech Hotline If you need help from an AspenTech Customer Support engineer, contact our Hotline for any of the following locations: If you are located in: Phone Number Fax Number E-Mail Address North America & the Caribbean +1-617/949-1021 +1-888/996-7001 (toll free) +1-617/949-1724 support@aspentech.com South America (Argentina office) (Brazil office) +54-11/4393-5308 +55-11/5506-0756 +54-11/4394-8621 +55-11/5506-0567 tecnoba@aspentech.com tecnosp@aspentech.com Europe, Gulf Region, & Africa (Brussels office) (UK office) +32-2/724-0100 +44-1223/312220 +32-2/705-4034 +44-1223/366980 atesupport@aspentech.com Japan +81-3/3262-1743 +81-3/3262-1744 atjsupport@aspentech.com Asia & Australia (Hong Kong office) (Korea office) +85-2/2838-6077 +82-2/761-5800 +85-2/2833-5642 +82-2/761-5803 atasupport@aspentech.com ❖ ❖ ❖ ❖
Chapter1717ConvergenceThis chapter includes the following topics about convergence:Flowsheetrecycles and design specificationsConvergence OptionsSpecifyingtearstreamsUser-defined convergence blocksConvergence MethodsUser-defined convergence orderSpecifyingthecalculation sequenceInitialguessesFlowsheet sequencingChecking resultsControl panel messagesStrategies for flowsheet convergenceFlowsheet Recycles and DesignSpecificationsAspen Plus performs flowsheet calculations using the sequential modular methodEach unit operation block is executed in sequence.Thecalculated output streamsofeachblockareusedasfeedtothenextblock.Flowsheetswithrecycleloops,design specifications,oroptimizationproblemsmust be solved iteratively.Execution requires that:Tear streams are chosen.Atear stream is a recycle stream with componentflows, total mole flow, pressure, and enthalpy all determined by iteration.Itcanbeanystreaminaloop17-1AspenPlusUserGuideVersion 10.1-0
Aspen Plus User Guide 17-1 Version 10.1-0 Chapter 17 17 Convergence This chapter includes the following topics about convergence: • Flowsheet recycles and design specifications • Convergence Options • Specifying tear streams • User-defined convergence blocks • Convergence Methods • User-defined convergence order • Specifying the calculation sequence • Initial guesses • Flowsheet sequencing • Checking results • Control panel messages • Strategies for flowsheet convergence Flowsheet Recycles and Design Specifications Aspen Plus performs flowsheet calculations using the sequential modular method. Each unit operation block is executed in sequence. The calculated output streams of each block are used as feed to the next block. Flowsheets with recycle loops, design specifications, or optimization problems must be solved iteratively. Execution requires that: • Tear streams are chosen. A tear stream is a recycle stream with component flows, total mole flow, pressure, and enthalpy all determined by iteration. It can be any stream in a loop