Proactive Optimization and Control of Heat-Exchanger Super Networks

This paper presents an integrated approach for the optimization and control of heat-exchanger networks (HENs) that are managed proactively, where both renewable energy generation and time-varying electricity pricing are considered in calculating the utility cost and revenues. A real-time optimization strategy is carried out to deal with the resulting variability in energy resource availability and costs. The heat-exchanger super structures are first defined where transitions between the included HEN sub structures are assumed to be instantaneous. The optimal configurations are sent to the local controllers as structural set points to be implemented. The explicit nonlinear models of heat exchangers built in Aspen Plus® are adopted to describe the dynamic behaviors of the HENs. The dynamic models are incorporated not only for simulating the local control scheme but also the supervisory level to account for the structural transitions that incur operational and possibly capital costs.