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Based On The Operating Conditions To Determine The Coke Oven Flue Temperature Integrated Intelligent Control Method

Posted on:2009-09-06Degree:MasterType:Thesis
Country:ChinaCandidate:P LiFull Text:PDF
GTID:2191360245982471Subject:Control Science and Engineering
Abstract/Summary:PDF Full Text Request
The combustion heating process of coke oven is a very complex industrial process. The features of multi-variable, nonlinearity, time-large -lag, complex operative-modes, and hard in modeling are the major control challenges in the combustion heating process of coke oven. Flue temperature is a key factor affecting the combustion process. Therefore, how to determine the right gas flowing rate and flue suction to stabilize the flue temperature and make the coke oven burning in the optimal status is the most critical problem for the tracking control of the flue temperature.It is difficult to control the flue temperature owing to the complexity of the operative modes. In this thesis, the mechanism of coking process is analized and the method in which, the raw gas temperature is used to identify the operative mode based on the information fusion in decision level is presented. At first, trend analysis method is adopted to judge if the temperature sensors in the rising pipes can be used to judge operative modes. Then, the operative mode in single coking chamber is identified with expert rules. At last, information is fusioned with the weighted Least Squares Support Vector Machines (WLS-SVM) to get the operative mode of the coke oven. Through the operative modes judegement, a new method for data analysis in slow industrial process is offered as well as the control problem in each operative mode is relatively simple.An intelligent integrated control's structure in which the control system is devided into 2 loops for the flue temperature of coke oven is set up for the flue temperature's control in different operative modes. The major loop is for the temperature intelligent control, which builds a multi-state-model based fuzzy expert control model based on the weighting efficient through analyzing the combustion heating process of coke oven. At the same time, a soft-switch control strategy is established, which can switch the controller's states depending on the result of the operative mode judgment module such that the complexity of the control for the flue temperature of coke oven is brought down. On the other hand, the thesis builds a model based on the relationship between the flue suction and the gas flowing rate, and the gas flux and the air suction are regulated to sustain the flue temperature stable. The minor loop for the valve control, which designs a valve controller with intelligent control method, can keep the flue suction and the gas flowing rate stable and exact.In this thesis, the intelligent integrates control of flue temperature is implemented with VC++ as its development tool and with OPC as its communication method on the platform of WinCC. The result of real-time control proves that the algorithm is high-performance. The control system can reduce fluctuate of the flue temperature and ensure the optimal combustion in the coke oven. Meanwhile, it also lessens the labour intensity. In a word, it provides an efficient method for the intelligent control in the coke oven's combustion heating process.
Keywords/Search Tags:coke oven, flue temperature, gas flowing rate, Support Vector Machines, Operative mode judgment, multi-state-model based fuzzy control, Intelligent integrates control
PDF Full Text Request
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