| In the current cement industry automation control system,the application of DCS is becoming more and more mature.For the large-scale New Suspension Preheater dry process cement production line((NSP cement production line or New Dry Process Cement Production Line),the distributed control system(DCS)based on programmable logic controller(PLC)is the most widely used in terms of cost and practical application.By consulting and analyzing the relevant literature of the cement process and DCS control system,combined with the requirements of the new high solid-gas ratio cement production process for the DCS control system,according to the actual situation of the project,this paper completed the 2X6500t/d NSP cement production line The hardware configuration and software design of the DCS control system.According to the process and production links of the 2X6500t/d clinker new dry-process cement production line,it is divided into Local Control Stations and Remote Control Stations,and the DCS system structure is determined.Through the analysis of the electrical equipment and measuring points of instruments in each process of the 2X6500t/d NSP cement production line,the number of control points required for each process section was calculated,and the total number of control points for the whole plant was finally determined.From the three aspects of Local Control Stations,the Communication Network,the Central Control Room Operating Station,the requirements were analyzed.According to the statistics,the Unity Quantum series control platform of Schneider was used for hardware configuration.Using Schneider’s Unity Pro 7.0 programming software,combined with the analysis of the NSP cement production process,the program structure was built,and the programming strategy of each program and important equipment was analyzed.Based on the program structure,define various data types and write subprogram codes.When the program of the lower computer is completed,use the Vijeo Citect V7.2 software of Schneider to design the picture of the upper computer according to the process flow,and then read the required data from the lower computer through Modbus Plus(MB+)and link to the corresponding picture.Finally complete the entire software design work of the cement plant.In current industrial automation control systems such as cement production line and slag production line,according to the priority of control authority,two motor control methods are often used: the machine-side priority control method(or the local priority control method)and the central control room priority control method(or the remote priority control method).For the former,it has been familiar and widely used.For the latter,many electricians are very unfamiliar,but there are more and more applications.Based on the author’s application and experience in practical projects,this paper focuses on the specific implementation methods and characteristics of the central control priority control method,and gives suggestions for suitable places according to the differences between them.Based on the analysis of the production process requirements of the large-scale NSP cement production line,the electrical control requirements of imported equipment,and the instrument testing requirements,this paper determines the DCS system structure and configuration,and realizes the automatic control function through software programming and configuration..The optimization of the electrical control system and the DCS system makes the equipment and personnel safer,ensuring the reliable operation of the large-scale new dry cement production line process equipment,stabilizing the process parameters,ensuring product quality,saving energy,and improving the operation rate of the production line.According to the design scheme and ideas proposed in this paper,an automated control system for a cement production line has been successfully realized. |
