Production Analysis And Abnormality Diagnosis Research Of Intermittent Coal Gasification System Based On Data Mining

With the development of chemical technology,chemical industry has made rapid process in recent years.As the main consumption force of non-renewable energy in chemical industry,the automatic control of the production process of synthetic ammonia has been the key research in the field of chemical industry.At the same time,in the production process of ammonia synthesis,the energy consumption of the intermittent coal gas-generating section is the highest.Therefor the research on the craft and automatic control of the intermittent coal gas-generating section will improve the production efficiency,reduce the energy waste and promote the development of the synthetic ammonia industry.The difficulty of the research in the chemical production control process of the intermittent gas-generating section mainly owes to the complicated gas-making process and constantly changed real-time data and data relationship,which will increase the difficulty of the establishment of the suitable real-time control transfer function and control model.At present,the research of this field is not enough.Technical operators always take control operation based on their own experience.Even in some small and medium-sized chemical enterprises,they all use manual remote controller to go on the control work which makes it difficult for chemical operators to make timely and accurate treatment to the abnormality in the coal gas-generating section,resulting in serious waste of raw materials,low production capacity and serious environmental pollution.Therefore,if the historical production data can be well analyzed and studied,and the results can be used to guide the actual automated control production,the control accuracy and the control intelligence will be greatly improved,which will enhance the chemical production efficiency and reduce the energy consumption and promote the development of chemical enterprises greatly.Based on the low automatic control level faced with by small and medium-sized chemical enterprises,this paper will take the automatic control rectification project of the intermittent coal gasification section of the synthetic ammonia industry in Shunchang Fu Bao Industrial Co.Ltd as the research object and take the historical production data of the intermittent coal gasification as the original data,make analysis and research to the control process of the intermittent coal gasification to provide guidance for the automatic control rectification project which will based on the original production process.In summary,the main contents are as follows:(1)Go on the data missing research,data exception research and data denoising research to the historical production data.(2)Go on production formula clustering analysis to the intermittent coal gasification furnace based on the fuzzy C-means clustering to get the best production formula and the best production status data to provide data reference for the PID automatic controller and the research of abnormality diagnosis and recognition.(3)Go on factor analysis to the production environment monitoring indicators of the intermittent coal gasification section to get the abstract production environment monitoring factors.(4)Go on the research of production abnormality diagnosis and identification based on PCA and KPCA,and get the appropriate abnormality diagnosis and identification solution to the intermittent coal gasification section.(5)Construct a multiple regression model to find the key control indicator of the yield of goal gas,and propose a better scheme to optimize the location of control indicators based on the design of the actual gasification furnace.The results are as follows:(1)The three-layer wavelet soft-threshold denoising method which takes 1.4556,1.823 and 2.768 as the three thresholds can get rid of the most white noise contained in the historical production data and keep the spikes and feature points of the original data as much as possible.(2)The optimum production formula of the intermittent coal gasification furnace is as follows:289 units of the top temperature of the furnace,218 units of the bottom temperature of the furnace,118 units of the blowing cycle time,1.4863 units of the idle height,18 units of insulation liquid level,218 units of the grate slagging speed.This production formula can be taken as the best production status to guide the parameter setting of the PID automatic controller and the data in this class which contains this production formula will be the optimal historical production data.(3)Among the obtained abstract factors,factor Y1 can be used to measure whether the outcome of all the production stages conforms to the requirements of the production process,factor Y2 can be used to measure whether the temperature of intermittent coal gasification furnace conforms to the requirements of the production process,factor Y3 can be used to measure whether the gasification results conforms to the requirements of the next production section,factor Y4 can be used to measure the control sensitivity of each valve,factor Y5 can be used to measure the yield and the use situation of the half water coal gas in the next section.The operators can make a wide range monitoring and judgment to the intermittent coal gasification furnace according to these abstract indicators.(4)As a linear production system,the intermittent coal gasification control system can use the method of PCA to go on the abnormality monitoring and diagnosis.(5)Adding thermometers on the upper and lower delivery tubes respectively and adding pressure gauges and control valves on the upper and lower intake tubes respectively can make the two types of chemical reaction in the furnace monitored separately,and achieve the goal to control the final yield of the half water coal gas accurately.