Index analysis of unsteady-state chemical process systems—II. Strategies for determining the overall flowsheet index

Abstract Strategies are presented for predicting the overall index of dynamic flowsheet models given the indices of single units, or groups of units, and the topology of the flowsheet. As a result, the task of estimating the entire flowsheet index becomes more manageable since it can be dealt with by solving a number of smaller index identification problems. If this cannot be done at the individual unit level, the algorithm given here determines the groups of units that must be considered together for index identification purposes. A number of test problems representing relatively complex flowsheets are used to demonstrate the use of these techniques.