Concentration soft measurement method of dividing wall rectifying tower

Abstract

The invention relates to a concentration soft measurement method of a dividing wall rectifying tower, and belongs to soft measurement methods in the chemical process. According to the concentration soft measurement method integrated with the data driving model, concentration soft measurement is added on the basis of cascade control of the temperature and the concentration of the dividing wall rectifying tower so that the prediction of the product concentration is realized by detecting easily detected variables. The inner layer in cascade control adopts proportional integral control to controlthe temperature of the sensitive plate of the dividing wall rectifying tower; and the outer layer adopts model prediction control to control the product concentration. With application of the method,the product concentration is predicted by fully utilizing auxiliary variables which are easy to detect so that high price and long time delay of real-time online concentration detection are avoided; and proportional integral control and model predictive control are fully combined to realize rapid error-free control of the dividing wall rectifying tower.

Description

technical field [0001] The invention relates to a product concentration control method of a partition wall rectification tower, in particular to a concentration soft measurement method integrated with a data-driven model, which belongs to the soft measurement method of chemical process. Background technique [0002] The dividing wall rectification tower is a thermally coupled rectification tower that integrates two (or more) rectification towers into one tower shell to realize the separation of ternary (and above) systems. Compared with the traditional rectification column system, the dividing wall distillation column can usually save about 30% of energy consumption, save about 30% of equipment investment, and save space. Among them, the four-component Kaibel dividing wall distillation column is an important type of dividing wall distillation column. It is composed of a pre-fractionation column and a main column. to connect to each other. Four products are extracted from t...

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Problems solved by technology

However, pure temperature control has a steady-state residual error of product concentration, so it is also necessary to control the product concentration

Conventional concentration detection is prolonged, expensive, and continuous measurement cannot be achieved. However, according to the MESH equation of the rectification tower (each component's material balance equation, phase balance equation, normalization equation and heat balance equation at each balance stage), The variables (concentration, temperature, pressure and flow) in the rectification column are interrelated, therefore, the product concentration can be predicted by the easily detectable auxiliary variables (temperature, pressure and flow), and the product concentration of the dividing wall distillation column can be realized. soft measurement

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