Dynamic Control Of Conventional Vapor Recompression Assisted Dividing Wall Column

Distillation is the most widely used but higher energy-consuming and lower heat efficient unit operation process.As an implementation form of complete thermal coupling distillation,the distillation column(DWC)has obvious energy-saving effect,and the conventional vapor recompression assisted dividing wall column(VRC-DWC)can further improve its energy-saving effect which refers to the process that the vapor recompression system located between the overhead and the bottom of the DWC.However,the realization of the energy-saving effect of this complex process is based on the effective control.There are many variables and they affect each other in this type of process.Therefore,it is necessary to study the dynamic control of the VRC-DWC process.In this paper,we studied the effective control structure of the VRC-DWC process in detail.Firstly,we concluded the development and research status of this field,and then studied the dynamic control of the conventional DWC.The control structure of fixed liquid split and active vapor split were determined.Next,we proposed three types of steady-state simulation processes of VRC-DWC.In the three types of processes,the partitions are located at the upper middle,the right middle and the lower middle part of DWC.Based on the steady-state results,we studied the dynamic control structures of three types of VRC-DWC.The results showed that the control structure of controlling the bottom product purity by manipulating the compression work of the compressor and controlling the outlet temperature of the heat stream from the bottom heat exchanger by manipulating the bottom liquid flowrate can well control the VRC-DWC effectively.Finally,the important content of this article is summarized.