Financial Risk Management in Heat Exchanger Networks Considering Multiple Utility Sources with Uncertain Costs

In a plant, different utilities may be produced from different sources whose costs vary singularly. Therefore, evaluating the financial risk associated with heat exchanger networks (HEN) with multiple utilities is essential. This work aims to address the HEN synthesis under uncertainty by presenting several optimization models for managing financial risk. To this end, three different risk metrics are employed: variability index, downside risk, and risk area ratio. The resulting models are based on an enhanced version of the stage-wise superstructure, which incorporates the potential to place utilities at all HEN stages. The study considers fixed utility sources as well as the possibility to vary those yearly. Furthermore, we propose a novel “pseudointersection” calculation scheme for the risk area ratio metric, which proves efficient in assessing how risks can be reduced at minimal opportunity loss. The proposed models are able to efficiently identify solutions appealing to different investor profiles.