An Equation-Based Approach to Transition Specifications in Material Flow Networks

Material flow analysis (MFA) describes a class of methods that allow analysing and designing material and energy flow systems like supply chains, eco-industrial parks or production sites. Material flow networks are one of the methods in the field of MFA. Based on the Petri nets, the material flow network make it possible to conduct static MFA (steady-state modelling) as well as dynamic MFA (continuous and discrete-event simulation). In this contribution focus will be on the important building blocks of material flow networks: transitions. Transition specifications can be regarded as parameterized sub-models, which may exhibit nonlinear behaviour. Linear transition specifications that consist of fixed production coefficients are always not adequate to represent the sub-models. In the following a more powerful equation-based approach to process flowsheeting is discussed. The equation-based approach makes it possible to specify a transition with aid of a system of non-linear algebraic equation including parameters, design specifications and loops.