Passivity Based Control Of Heat Exchanger Networks With Application To Nuclear Heating

Due to the common existence of heat exchanger networks (HENs) in fossil, nuclear and chemical plants, the synthesis and control of HENs play a key role in guaranteeing the plant operation performance. With comparison to the HEN synthesis (HES) that optimizes the topology and steady operation point of a HEN, the control of HEN provides satisfactory transient performance under load variations as well as interior and exterior disturbances. Without a properly designed control law, the optimized operation point of HEN cannot be maintained stably, which shows the importance of HEN control. In this paper, a dynamic model of HEN is first given based on the thermodynamics of a single heat exchanger and the directed graph describing the interconnection amongst multiple heat exchangers as well as heat sources and sinks. By adopting the total entransy as the corresponding storage function, it is also shown that the dynamics of HEN is strictly passive. Then, a passivity-based control of HEN is newly proposed, which can provide globally asymptotic stability while taking a simple form. Finally, the designed HEN control law is applied to the regulation of a HEN for nuclear district heating, and numerical simulation results not only verifies the theoretical results but also shows the satisfactory control performance.(c) 2021 Elsevier Ltd. All rights reserved.