Research On The Control Of Calcining And Cooling Processes In The NSP Cement Production

Calcining and cooling processes of clinker of the Cement production line, whose working-status determines the quality and output of cement clinker directly, play an extremely important role in NSP cement production. However, these processes have the multivariable, the Strong coupling, the big time lag and so on the characteristics , so that these processes have long been the focus and difficult of the cement production process control. At present, the control software for the cement clinker calcining and cooling system is still at exploration and simulation stage, whose field application is not ideal, only a small number of simple control methods such as PID control, are successfully applied to the field of cement production line. Abroad control software often results in "acclimatized", because the measurement points are less, the condition is complex and other characteristic in the domestic cement industry. Therefore, it is an urgent problem that how to realize the automatic control of the calcining and cooling processes of clinker, to improve the level of automatic control of cement production and reduce labor intensity.Through analysis of the characteristics about calcining and cooling processes of clinker, and in-depth analysis of influence factors of calcining and cooling processes of clinker by the actual situation, thus summarized expert experience to select process parameters and control points reasonably. Finally, control scheme was proposed which contrapose the abnormal and abnormal working-status of cement calcining and cooling of clinker processes. The control scheme was successfully applied to the company production site.Five parameters, which include kiln main motor current, decomposing furnace outlet temperature, the first room pressure of cooler, the second and the third pressure of cooler grate bed, are chose to be input parameters according to the caft and working-status of cement production. After data preprocessing, these key parameters are identified for the special conditions, in order to facilitate the control for the different working conditions respectively.Calcining and cooling of clinker processes control scheme was proposed according to the operators control thought. Fuzzy-PID compound algorithm is control real-time speed of grate cooler in the normal working-status, which according to the pressure in the grate cooler. Fuzzy-PID compound algorithm control uses fuzzy control when the deviation is larger and uses PID control when the deviation is small ,in order to improve the response speed and the dynamic characteristics of the adjustment process; Expert experience is used to control speed of rotary kiln and kiln head pulverized coal in the abnormal working-status to improve kiln-status. Meanwhile, the output of fuzzy-PID control need to be modified through expert experience to reduce influence for cooling system from abnormal working-status.The software of this system of calcining and cooling of clinker processes control scheme is realized using C++.Based on OPC technology to read the site engineers stood real-time data, and can set control goal and output range according to the situation. The proposed control scheme can better finish the the automatic control for calcining and cooling of clinker processes. Compared to manual operation, this operation results demonstrate the effectiveness and practicality of this solution.