Multivariable Control Structure Design of Heat Exchange Networks Based on Mixed-Integer Quadratic Programming

LAUTARO BRACCIA; DAVID ZUMOFFEN; PATRICIO LUPPI; PABLO MARCHETTI

13th INTERNATIONAL SYMPOSIUM ON PROCESS SYSTEMS ENGINEERING (PSE 2018)

ELSEVIER

Lugar: Amsterdam; Año: 2018; p. 601 - 606

In this work, a new systematic methodology toaddress multivariable control structure (MCS) design for heat exchange networks(HENs) is proposed. This methodology is based on recent developments presentedby Braccia et al. (2017) where the MCS design for medium/large-scale processes isperformed based on a mixed-integer quadratic programming (MIQP) formulation. Thismethodology is based on an equation-oriented superstructure which addressessimultaneously: the selection of controlled variables (CVs) and manipulatedvariables (MVs), the input-output pairing definition, the controller topology,the initial heuristics considerations, and the stability test by usingsteady-state information only. Usually, in the HENs cases, all the outputsvariables need to be controlled, i.e. there are no uncontrolled variables. Inthis context, the MCS design procedure presented in Braccia et al. (2017)requires a reformulation to quantify the manipulated variables instead of the uncontrolledvariables. Furthermore, some modifications of the original MIQP algorithmrelated to the augmented functional cost are analyzed. The performance of differentcontroller topologies, i.e. decentralized, sparse, and full, are evaluated. Twoexamples are given in this work to illustrate the potential of the proposedmethodology and to support the final conclusions.