On-line calculation and self-adaptation nonlinear prediction control method of catalytic cracking reaction depth

Abstract

The invention relates to an on-line calculation and self-adaptation nonlinear prediction control method of a catalytic cracking reaction depth, belonging to the technical field of automatic control of industrial processes. The method is characterized by comprising the following steps of: correcting the parameter of a regeneration valve flow characteristic model on line by utilizing a relatively accurate catalyst circulating amount obtained by calculating the heat balance of a regenerator; then finishing the real-time calculation of the catalyst circulating amount based on the corrected regeneration valve flow characteristic model; and on that basis, calculating the catalytic cracking reaction heat on line based on a riser dynamic mathematical model and realizing the self-adaptation nonlinear prediction control of the riser reaction depth.

Description

technical field [0001] The invention relates to an on-line calculation of catalytic cracking reaction depth and an adaptive nonlinear predictive control method, which belongs to the field of soft measurement and automatic control of catalytic cracking production process in petrochemical industry. Background technique [0002] Catalytic cracking unit is one of the most important heavy oil conversion units in petroleum refineries. Under the action of heat and catalyst, the raw oil will crack the heavy oil and transform it into high-value products such as rich gas, gasoline and diesel. In terms of economic benefits, more than half of the benefits of oil refineries are obtained by catalytic cracking. Therefore, the application of advanced optimization control technology to realize the stable operation of the device and provide conditions for online optimization undoubtedly has important practical significance and obvious economic benefits. [0003] Most of the existing catalyt...

AI Technical Summary

Problems solved by technology

[0006] 1. Calculation of catalyst circulation by regenerator heat balance has high accuracy, but there is a certain time lag due to the measurement of flue gas oxygen content; the raw catalyst flows from the riser to the regenerator through the stripping section, and its temperature and coke content are relatively large. All regenerators have a time lag of 1-2 minutes, and the real-time performance of the calculation cannot meet the requirements for advanced control of the riser

[0007] 2. The carbon determination of the unborn catalyst and the regenerated catalyst can only be obtained through offline testing, which has a considerable time lag. Therefore, the use of carbon balance method to calculate the catalyst circulation amount cannot meet the real-time requirements of production monitoring and control

When the opening of the regeneration valve changes greatly or the fluidization state of the catalyst changes, if a fixed regeneration valve characteristic model is used for calculation, its accuracy will not be guaranteed

Images