An approach for hybrid simulation of batch processes

The paper proposes a method to simulate chemical batch processes. Simulation is a commonly used tool in the phase of planning and during operation of batch processes. Batch processes are discontinuous processes. They have characteristics of both worlds, discrete and continuous, what usually leads to a recipe-based process controller design. The control structures are modular and hierarchic. An one-to-one mapping of control structures and model modules has to be achieved. For this purpose a modeling formalism is used which the authors call net condition/event systems (NCES). Using this discrete-event system, we abstract the discrete characteristics of the batch process. Modeling the continuous behavior of the batch process leads to a system of time dependent algebraic and differential equations. For solving the equation system, the authors use a widely recognized commercial simulation package. Embedding NCES in a continuous simulation environment via a state and time event interface enables us to introduce states and conditions for state transitions necessary for batch process simulation.