Full Cycle Optimal Control Due to Slow Time-varying Fouling Characteristics for Heat Exchanger Networks with Slow-Release Margin

Considering the full cycle running of heat exchanger networks, operating margin and control performance are necessary to ensure a sustainable, profitable, and safe operation. An approach for operating online and saving energy continuously in the heat exchanger networks (HENs) is presented. In this work, the relationships between the design margin and the control system are analyzed by the whole cycle running simulation. A new full cycle optimal control due to slow time-varying fouling characteristics control framework is proposed to satisfy control performance and slow-release margin. The control performance is calculated in the dynamic process. The available margin of the heat exchangers is considered once the control performance is satisfied. The switching point of optimization method is solved by phase trajectory. Margin slow released full cycle optimization is established. Results show that the proposed method can enhance the control performance and release the margin to achieve energy conservation.