## Project Details

### Description

Flowsheet decomposition and equation ordering

Solution of flowsheet simulation problems with the modular approach requires flowsheet decomposition techniques so that the appropriate calculation order can be specified to the solver. The same problem when solved with the equation oriented approach, needs the equations to be ordered (if possible) in a particular manner so that the solution efficiency can be improved. In an integrated approach to process simulation, design and control, the simulation engine needs to be flexible so that it is possible to move from one mode of simulation to another without much extra work. Also, if simulation engine is provided from two different sources employing two different solution approaches, they may need to interact through a common set of variables. It may also be that in the same process flowsheet, one part is suitable for solution with the modular approach while another part may be suitable for the equation oriented approach. The same may be true for dynamic simulation of a process flowsheet containing dynamic and non-dynamic units. The objective of this project is to determine appropriate simulation strategies for the simulation engine so that mixed mode (steady state/dynamic, equation oriented/modular, ODE/DAE) simulation is possible with increased solution efficiency and robustness. Since all simulation problems need the same flowsheet topology information, this information may also be used to link flowsheet decomposition and equation ordering.

ICAS (see program E) has a built-in feature for defining any problem specific simulation strategy. Current and future work will take these ideas further with a view to the development of generalized strategies of wide application range.

Solution of flowsheet simulation problems with the modular approach requires flowsheet decomposition techniques so that the appropriate calculation order can be specified to the solver. The same problem when solved with the equation oriented approach, needs the equations to be ordered (if possible) in a particular manner so that the solution efficiency can be improved. In an integrated approach to process simulation, design and control, the simulation engine needs to be flexible so that it is possible to move from one mode of simulation to another without much extra work. Also, if simulation engine is provided from two different sources employing two different solution approaches, they may need to interact through a common set of variables. It may also be that in the same process flowsheet, one part is suitable for solution with the modular approach while another part may be suitable for the equation oriented approach. The same may be true for dynamic simulation of a process flowsheet containing dynamic and non-dynamic units. The objective of this project is to determine appropriate simulation strategies for the simulation engine so that mixed mode (steady state/dynamic, equation oriented/modular, ODE/DAE) simulation is possible with increased solution efficiency and robustness. Since all simulation problems need the same flowsheet topology information, this information may also be used to link flowsheet decomposition and equation ordering.

ICAS (see program E) has a built-in feature for defining any problem specific simulation strategy. Current and future work will take these ideas further with a view to the development of generalized strategies of wide application range.

Status | Active |
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Effective start/end date | 01/05/1997 → … |