| Calciner as a core device of NSP kiln, its main function is to undertake the task ofCaCO3decomposition and its coal consumption accounts for about60%of cement clinkeringprocess. In the domestic, traditional control methods and foreign advanced control system cannot achieve a desired effect in domestic cement companies caused by frequent changes inproduction conditions, less monitoring and control point and the characteristics of calciner,such as non-linear, large time delay, time-varying. So most of domestic cement using manualcontrol for calciner, but manual control method exiting a lot of programs such as calcinertemperature fluctuations, low yield, poor quality of clinker and large energy consumption.Automatic control for calciner in cement enterprise has not been widely promotion, andoptimal control is less involved. Therefore, from domestic cement calciner control presentsituation, using the advanced control technology to realize the optimal control for cementcalciner optimization has a great significance for the cement clinker normal production andcement enterprises to realize saving energy and reducing consumption. This paper based onNatural Science Fund projects in Shandong province and a domestic cement company5000t/d of clinker line DCS system as the application background, to complete the cement calcineroptimal control system design and software development. In this paper the main researchresults obtained as follows:(1) The calciner optimal control system is divided into two parts including calcinertemperature optimal setting system and calciner temperature automatic control system.Calciner optimal setting system gives the current optimal value under the current condition.Calciner temperature automatic control system uses multi-model intelligent control to stablethe calciner temperature on the optimal value. Through above method make calciner operationin low coal consumption status.(2) Calciner temperature optimal setting system. Based on the cement technology, thecalciner temperature optimal setting model is set up. The model consists of the calcinertemperature presetting model based on LS-SVM, calciner temperature setting compensationmodel based on experts system and calciner temperature setting correction model based onFuzzy system. Meet the technological requirements in cement, calciner temperature presetting model based on LS-SVM given the current presetting value under the current condition, thenthrough the calciner temperature setting compensation model based on experts system andcalciner temperature setting correction model based on Fuzzy system compensation andcorrection the presetting value, draw the calciner temperature is the optimal value undercurrent conditions.(3) Calciner temperature automatic control system. In order to overcome the controldifficulties result from the characteristics of calciner, such as non-linear, time-varying, largetime delay, a multi-mode intelligent control method is proposed in the paper by thecombination of Fuzzy control, Bang-Bang control, feed-forward control, expert control andvariable integral PID control. This control method through a multi-mode intelligent controlrules automatically identify the different modes and select a appropriate control algorithm tocorrect variable integral PID control to stable the calciner temperature on the optimal value.(4) Based on the control scheme, from industrial application actual conditions, developedcalciner optimization system software. Software consists of OPC Client software, operatorsstand configuration software interface and cement calciner optimal control algorithm software.The system using the OPC realized the communication with DCS.Field application prove, optimal system improved the decomposition rate, reduced laborintensity, stabled calciner temperature, reduced the coal consumption, realized the high quality,high yield and clinker low coal production, brought huge economic effect to the enterprise,complied with the state’s saving energy and reducing consumption policy. |
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