An object oriented framework for developing dynamic models of a paper machine

An object oriented component library is being built for the dynamic simulation of systems in a paper mill. Ever increasing demands for quality require better performance in all areas of paper making. In order to improve these complex systems it is necessary to have a testbed on which to learn about the system, and evaluate performance of new ideas (like control strategies). Modelling of a paper machine approach system is used as the basis for developing a structure that will be expanded to include blocks for simulation of all parts of the paper mill. The simulation components are being built in the modelling language OMOLA for use with the dynamic simulation tool, OmSim. This is an object oriented environment which uses true differential equations and noncausal modelling together with a simultaneous system simulation package. The design attempts to take full advantage of the object oriented and modular features of OmSim, in order to create a class library that can easily be expanded to encompass new components of the mill, and to allow for easy selection of varying submodel complexity. This paper introduces some fundamentals of the OMOLA modelling language, discusses the main features, key to the flexibility of the design, and demonstrates the use of the blocks to simulate the pulp flows from the machine chest to the headbox of a high speed newsprint machine.