A binary distillation tower temperature control system and method

Abstract

The invention discloses a temperature control system and method of a binary distillation tower, and relates to the synthesis and design of the temperature inference control system of the binary distillation tower with low, medium and high product concentrations. For the binary distillation column with medium and high product concentration, neither the method of sensitivity nor the method of minimum steady-state deviation can give a temperature inference control system with good performance. The invention proposes a new method in which the sensitivity and the minimum steady-state deviation are compromised in the rectifying section, and the temperature difference is selected as the controlled variable in the stripping section. The former helps to achieve the balance between the steady-state characteristics and dynamic characteristics of the controlled tray, and the latter can avoid the adverse effects of pressure changes in the stripping section. It is very effective for neutralizing binary distillation towers with high product concentrations; it is also superior to methods with minimum sensitivity and steady-state deviation for low product concentration binary distillation towers. Not only the steady-state deviation decreased more, but also the dynamic deviation of the controlled product concentration decreased.

Description

technical field [0001] The invention relates to the synthesis and design technology of a distillation tower temperature control system, which belongs to the operation and control of chemical process. Background technique [0002] Due to the strong internal coupling, complex dynamic characteristics and long lag time of the distillation tower, the synthesis and design of its control system are highly complex, which has seriously affected the control effect of product quality. Therefore, the research on the operation and Optimal control has always been a research hotspot. Although the concentration control can realize the unbiased control of the purity of the controlled product, the use of the concentration measurement device will lead to the disadvantages of high investment cost, high maintenance cost and long adjustment time of the control system, which greatly limits its industrial application. On the contrary, temperature control is widely favored in the process industry d...

AI Technical Summary

Problems solved by technology

Although these methods are usually effective in determining the position of the controlled tray, they also often make it difficult for the temperature inference control system to give the best control quality

These deficiencies not only limit the effective application of temperature inferential control systems but also hinder the development of new distillation systems

Although the determination of controlled trays is an old subject in the field of distillation operations, it is still an important issue worthy of further study

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