A MILP algorithm for utilities pre-design based on the Pinch Analysis and an exergy criterion

• We develop an algorithm for utilities preselection.
• Exergy minimization identifies best heat recovery technologies.
• Speed calculation and results accuracy are guaranteed for large number of heat flows.
• Utilities are defined by both temperature levels and heat loads.
• Local utility retrofit leads to energy penalty in global energy integration studies.

Designing Heat Exchangers Network for heat recovery is a challenge currently solved with optimization algorithms. However, making a tradeoff between HEN and utilities rely on how relevant are the proposed utilities. In this paper we propose a preselection algorithm for utilities, focused on chillers, heat pumps, Organic Rankine Cycles (ORC) units and Combined Heat & Power (CHP) units. The Pinch Analysis is used to provide input data such as the Grand Composite Curve (GCC). A MILP algorithm based on an exergy criterion automatically preselects and predesigns utilities from the GCC. The formulation of the optimization problem is described, and so the degrees of freedom for the user. Finally, an example from Food & Drink industry shows the performance of this algorithm. Fast and accurate, this algorithm has been implemented in a software named CERES to prepare the results for the HEN design, which is not described in this article.