Research Of Monitoring And Controlling For Pneumatic Ash-Removing System In Plant

Ash-Removing system is the auxiliary treatment facilities of coal-fired power plant, and is used to clear away the large quantities of industrial waste produced in the power generation. Compressed air and fly ash are mixed under a certain proportion, then they are transported out along the pipeline. The performance of pneumatic ash-removing control system should meet the entire coal-fired unit's rapidity, high precision and high automation requirements.This paper discusses and studies the monitoring and controlling of pneumatic ash removing system in the power plant. In order to achieve processing automation and information management automation, the design idea of constituting a two-layer distributed monitor-control system structured is proposed, in which industrial computer and programmable logical controller are used. The total plan and designation are introduced of the control system, applied the theory of sequential control to the PLC program. The paper analyzes the main technical parameters about the conveying system in order to achieve the optimal results, and establishes mathematical model of the conveying system. In order to resolve the problem of materials can not be conveyed smoothly caused by the amount of ash changed in the pipe leading to changes of the motor load, incremental PID controller was applicable to the pneumatic ash control system. Variable integral incremental PID controller was designed because of the effects of deviation of size to control system.Through research the ash process, at the same time, based on the needs of the system functions and system reliability, this paper analysis and designs hardware system by using Siemens S7-300PLC as the controller. Siemens WinCC flexible2008 configuration software is selected to Monitor and control Ash handling equipment in the field.The simulation of speed-time response curve of drive motor indicates that variable integral incremental PID controller is superior to traditional PID controller and the control precision and response speed can be ensured. Experiments proved that this pneumatic ash removing system is safe, easy to control, and good human-computer interaction, which improved the automation and control level.