(236e) Software and Advanced Solution Methods for Flexibility Analysis

The importance of designing systems that can operate reliably and efficiently over a wide range of conditions has been growing rapidly. For example, power plants must be able to operate efficiently over a wide range of power outputs to effectively participate in the electric market, and the transmission system must satisfy demands with growing variability in generation sources such as renewables. However, analyzing flexibility remains a computationally challenging problem.

We present an open-source package for flexibility analysis as part of the IDAES ecosystem [1]. The package both streamlines the development of models for flexibility analysis and provides several advanced solution approaches, including vertex enumeration [2], the active constraint method [3], and machine-learning (ML) based decision rules. We demonstrate improved scalability through custom solution strategies which exploit the structure of the feasibility test problem and investigate the benefit of ML-based decision rules for nonconvex problems.

Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525. This work was funded by the Institute for the Design of Advanced Energy Systems (IDAES) with funding from the Office of Fossil Energy, Cross-Cutting Research, U.S. Department of Energy.

Works Cited

1. [1] A. Lee, J. Ghouse, J. Eslick, C. Laird, J. Siirola, M. Zamarripa, D. Gunter, J. Shinn, A. Dowling, D. Bhattacharyya, L. Biegler, A. Burgard and D. Miller, "The IDAES process modeling framework and model library - Flexibility for process simulation and optimization," Journal of Advanced Manufacturing and Processing, vol. 3, no. 3, p. e10095, 2021.

2. [2] R. Swaney and I. Grossmann, "An index for operational flexibility in chemical process design. Part I: Formulation and Theory," AIChE Journal, vol. 31, no. 4, pp. 621-630, 1985.

3. [3] I. Grossmann and C. Floudas, "Active constraint strategy for flexibility analysis in chemical processes," Computers & Chemical Engineering, vol. 11, no. 6, pp. 675-693, 1987.