Optimal Control Method Of Sustainable Energy Saving And Slow-release Margin For Heat Exchanger Networks

In the heat exchanger network,the application of control strategy can realize the online control of the system,but during the life cycle of the heat exchanger network,with the increasingly serious problems such as scaling of the heat exchanger,the operating point of the system will deviate from the original design point.At this time,in order to achieve the original control objectives,it is necessary to introduce utilities for adjustment,but the operating costs will be increased.On the other hand,the margin design for heat exchanger network can increase the operability in the control process,but it will lead to a significant increase in the investment cost.However,in the current research scheme,the optimal control scheme for the heat exchanger network is often to meet the control objectives and improve the control performance,which does not involve the utilization degree of the given design margin.Therefore,in order to optimize and control the whole life cycle of the heat exchanger network,it is necessary to consider the utilization and release degree of margin and control performance to ensure the continuous energy saving and effective operation of the heat exchanger network.In this paper,the relationship between control and continuous energy saving is analyzed,and a dynamic economic performance analysis method is proposed to analyze the system.A “fat” system structure involving control and optimization is proposed to solve the problem of margin release of heat exchanger network.In order to reduce the change of control variables,a control method of sustainable energy saving and slow-release margin optimization for heat exchanger networks is proposed.The switching point of the method is solved by using the principle of phase trajectory.On the premise of considering the control performance,the control system structure of heat exchanger network is designed by using the method of REGA(Relative Energy Gain Array)pairing.In the heat exchanger network with multi-bypasses,the bypasses are divided into the regulation bypasses for control and the optimization bypasses for optimization.Finally,the optimal control method of continuous energy saving and margin release for long-term process system is studied,and the simulation results are analyzed by using the dynamic economic performance index.