Research Of Cement Grate Cooler Optimal Control

Grate Cooler is an important device of NSP cement production. It can reduce thetemperature of clinker rapidly, improve clinker quality and grinding ability, and recycle heat.In the domestic, traditional control methods and foreign advanced control system can notachieve a desired effect in domestic cement companies caused by frequent changes inproduction conditions, less monitoring and control point and the characteristics of grate cooler,such as non-linear, large time delay, time-varying. So, foreign advanced control system cannot achieve a desired effect in domestic cement companies.Therefore, from domestic cementgrate cooler control present situation, using the advanced multimodal control technology torealize the optimal control for cement grate cooler optimization has a great significance.This paper based on Natural Science Fund projects in Shandong province and adomestic cement company5000t/d of clinker line DCS system as the application background,to complete the cement grate cooler optimal control system design and software development.In this paper the main research results obtained as follows:(1) The grate cooler optimal control system is divided into two parts including gratecooler pressure optimal setting system and grate cooler pressure automatic control system.grate cooler optimal setting system gives the current optimal value under the current condition.Grate cooler pressure automatic control system uses multi-model intelligent control to stablethe grate cooler pressure on the optimal value.(2) Grate cooler pressure optimal setting system. Based on the cement technology, thegrate cooler pressure optimal setting model is set up. The model consists of the grate coolerpressure presetting model based on LS-SVM, and grate cooler pressure setting correctionmodel based on Fuzzy system. Meet the technological requirements in cement, grate coolerpressure presetting model based on LS-SVM given the current presetting value under thecurrent condition, then through the grate cooler pressure setting correction model based onFuzzy system compensation and correction the presetting value, draw the grate coolerpressure is the optimal value under current conditions.(3) Grate cooler automatic control system. In order to overcome the control difficultiesresult from the characteristics of grate cooler, such as non-linear, time-varying, large time delay, a multi-mode intelligent control method is proposed in the paper by the combination ofFuzzy control, Bang-Bang control, expert control and variable integral PID control. Thiscontrol method through a multi-mode intelligent control rules automatically identify thedifferent modes and select a appropriate control algorithm to correct variable integral PIDcontrol to stable the grate cooler pressure on the optimal value.(4) Based on the control scheme, developed grate cooler optimization system software.Software consists of OPC Client software, operators stand configuration software interfaceand grate cooler optimal control algorithm software.