|
|
This section describes the differences that you might encounter between Aspen Plus V12.1 and Aspen Plus V11. In most cases, previous Aspen Plus input files and backup files are completely compatible with Aspen Plus V12.1.
When you open a file from a previous version, Aspen Plus displays the Upward Compatibility dialog box. If you select Maintain Upward Compatibility for Features Listed Below then Aspen Plus ignores the new features in all the areas mentioned on the dialog box (which may include new pure component databanks, property methods, built-in parameters, ADA/PCS procedures, calculated molecular weights obtained from formulas, and checking of user-specified sequence, depending on the version of Aspen Plus used to create the file).
Costing results from Exchanger Design & Rating or Economic Evaluation may change from one version to the next due to updated cost data.
Data for components in the NIST database can change from one database version to another, as NIST acquires and analyzes more data for those components. In the other databanks, specific changes may occur as noted below. If you have other versions installed, you can register another version of NIST in Aspen Properties Database Manager and on the Components | Specifications | Enterprise Database sheet specify to use that version instead of NISTV121.
New features in other areas, as noted below, may still cause different results in the new version. Flowsheet convergence may follow a different path in some cases, and flowsheets which converge only with difficulty in one version are especially likely to converge differently or fail to converge. These changes may have greater impact in flowsheets with loose tolerances due to convergence paths being different. AspenTech makes every effort to avoid making changes that result in incompatibilities with previous versions. The changes discussed in this section were necessary to correct problems (such as wrong results), to implement new features, or to improve ease-of-use.
The most important areas where you might encounter differences between Aspen Plus V12.1 and earlier versions are:
Fortran Compiler
Aspen Plus V12.1 was compiled with the Intel Fortran compiler 2017 and Microsoft Visual Studio 2017 as a 64-bit program. User Fortran models compiled with different compilers or compiler versions may not work, or may run but not be able to write to the history file, report file, and control panel. Only user models compiled with 64-bit compilers will work.
Convergence Monitor
In version V12, the Raw Value check box was missing, and it behaved as if the box was unchecked, showing the base 10 logarithm of the error criterion. The box has been restored for V12.1
Operating Year in Plant Data
In previous versions of Aspen Plus, the units involving the operating year were not converted correctly. Starting in V12.1 they are converted using the length of operating year specified on the Setup | Specifications | Global sheet when Plant Data was started.
Safety Analysis
Unwetted Fire Scenarios
In V12.1, you may notice a change in results for Unwetted Fire cases that use the Ref Stream Equation of State option for calculating relief temperature where the temperature and pressure of the scenario reference stream differ from the PRD system operating conditions.
Line Sizing
As a result of a fix to the problem where PSV line sizing failed to solve when the inclined or vertical method was Beggs & Brill, the inlet pressure drop calculated for PSVs may be reduced in some cases in V12.1 compared to earlier versions.
V12 included inaccurate results for the inlet line for cases with adiabatic gas or isothermal gas for the line sizing method. In V12.1, this issue was fixed.
Flash Subroutines
There are some changes in the interpretation of KRESLT in the flash subroutines. For details, see chapter 2 of Aspen Plus User Models.
Electrolyte-Polymer NRTL
The electrolyte-polymer NRTL model EPNRTL was meant to reduce to the electrolyte NRTL model in the absence of polymers and to the polymer NRTL model in the absence of electrolytes, but there were errors in its implementation, and the latter was not true. The model has been updated, and the density, enthalpy, Gibbs free energy, and entropy of mixtures calculated by the model has changed. It should now provide better predictions in general and more closely match the ideal of behaving the same way as polymer NRTL when there are polymers and are no electrolytes.
|
|
发表于 2022-10-16 14:04:38
显示全部楼层
IP卡
狗仔卡
楼主
提升卡
置顶卡
喧嚣卡
变色卡
千斤顶
显身卡