Andreas Kvarnström, Erik Dahlquist

Process optimization utilizing an external simulation model

Optimization of industrial processes is traditionally performed using personal knowledge and experience. Thanks to the recent years rapid computer development, optimization of industrial processes using computers and mathematical optimization algorithms have become possible and an excellent tool in the aspiration of more efficient processes. When performing computer-based optimization of processes it is often required to build a model of the process in the environment of the optimization software. Many companies have already made large investments in powerful simulation software for their specific processes and to rebuild the model in the optimization software environment adds more costs and may result in a less accurate simulation of the process. For that reason, it would be preferable to be able to use the already existing and better tuned simulator model of the specific process in the optimization. This paper describes a method of performing computer-based optimization of industrial processes using external simulation models. This approach is accomplished by establishing communication and interoperability between the optimization software and the simulation software using component-based software technology as Microsofts COM technology. In addition to the obvious benefit of not having to rebuild an already powerful and well tuned simulator model, is the easier maintenance and ability to change the process model using the graphical user interface often included in the simulation software. When using an external and a more process-specific simulation model there is also the advantage of having more functionality and process dynamics incorporated into the optimization, such as the mass and energy balances of the process and the quality characteristics of the product produced in the process. Using a more accurate process model also gives the possibility to check the feasibility of the optimization results where a larger scope of the process is simulated than is directly included into the objective function and constraints of the optimization.