ASPEN的一个奇怪问题？ 文件太大，先发个摘要，看看是否需要（另请告知如何发pdf的附件，版权问题如何弄？—— 严禁发布有版权争议的内容、如有争议追究发贴人。 ） abstract interest in discovering multiple steady-state solutions for reaction and separation processes has grown exponentially in the 1990s. existing process simulators like aspen plus and speedup are designed to obtain at best one solution. the user can use simulation programs to find multiple solutions only by the expenditure of much effort. of all current commercial process simulators only aspen plus allows the user to easily add user defined fortran subroutines that can be linked to the existing main program. in order to integrate aspen plus with a bifurcation program. one requires the jacobian matrix to detect turning points and bifurcation points and to enable branch switching. since aspen plus does not allow the user to access the jacobian rnatris. an alternative method based on process characteristics is developed. here. a bifurcation technique based on the use of arclength continuation is presented. which can be incorporated as an add-in subroutine to aspen plus. to automatically trace a solution path. including turning points. to obtain multiple solutions with respect to a user-selected parameter. the algorithms are based on a predictor-corrector implementation where the predictor pzns reside in add-in fortran blocks and the existing nonlinear equation solvers in aspen plus serve as the correctors. the advantage of this approach is that the robust nonlinear equation solvers already available in aspen plus are likely to perform better than the traditional newton solver present in all bihrcation packages for solving the chemical processes considered. furthermore, the existing physical property packages in aspen plus are also utilized. results are shown for an adiabatic cstr using the aspen rcstr model. and homogeneous azeotropic. heterogeneous azeotropic. and reactive distillation examples using the aspen plus radfrac model. in all four cases. the range of the selected bifurcation parameter covers a region containing three multiple solutions and provides a better understanding of the processes.查看更多
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