Design Of Intelligent Measurement And Control System For Coking Tower Top Corrosion

Refining enterprises are an important part of the national energy strategy.In recent years,with the deterioration of crude oil and the corrosion of equipment in refining and chemical enterprises,the loss of equipment is incalculable,which will not only cause economic losses of enterprises,but also cause serious environmental pollution and even accidents.Aiming at the problem of low temperature corrosion of coking tower top system in refining and chemical enterprises.This thesis designs an intelligent measurement and control system for coking tower top corrosion.This system can predict the corrosion rate of coking tower top based on real-time data,realize the automatic and accurate filling of water injection agent in tower top system,complete the calculation and real-time early warning of tower top environment and corrosion state,and effectively alleviate the corrosion of tower top.The specific research contents are as follows :(1)A corrosion rate prediction algorithm based on KPCA-DE-BP model is proposed.On the basis of clarifying the corrosion mechanism of the coking tower top system and determining the main factors affecting the corrosion of the tower top,the corrosion rate of the coking tower top is analyzed,and a corrosion prediction algorithm based on KPCA-DE-BP model is proposed.Firstly,KPCA algorithm is used to reduce the dimension of data,and then differential evolution algorithm,genetic algorithm and particle swarm optimization algorithm are introduced to optimize BP neural network model,which can avoid the simple BP neural network model falling into local optimal value.The results show that the proposed KPCA-DE-BP model algorithm has the best prediction accuracy and speed,and is more robust.(2)The three-phase flash calculation model is used to realize the accurate calculation of tower top water injection and injection system.Based on the gas-liquid equilibrium and thermodynamic model in the flash calculation model and the material composition of the coking tower top system,a flash calculation model of gashydrocarbon-water three-phase equilibrium was established.The composition and flow rate of each phase were calculated by using the algorithm based on free-water assumption and MRR(Modified Rachford-Rice)equation.Then,based on the established model,the saturated water injection and the amount of corrosion inhibitor are calculated,and the corrosion risk of the tower top system is judged.The results show that the three-phase flash model has high accuracy and reliability.(3)A set of coking tower top corrosion monitoring system was designed and developed.According to the actual industrial production needs and system functions,the overall architecture design is carried out.Adhering to the modular design scheme,the development and design of the coking tower top corrosion monitoring system is completed by using Win CC configuration design software,C language script and database,and the communication connection test with the lower computer controller S7-300 PLC is carried out.The final test results show that the functions of system login,main interface of process flow,parameter setting,corrosion prediction and alarm recording can be realized,which meets the automation requirements of coking tower top corrosion monitoring and control,thus verifying the feasibility of the system.