Design And Implementation Of Control System Of Coal-fired Power Boiler Ash Pneumatic Removing System

Ash handling system, chemical water system, coal conveying system arethree auxiliary systems of the coal-fired power plant. The role of ash handlingsystem is to transport a large amount of the fly ash，which is produced in theprocess of power generation.Not only ensuring the efficiency of coal-fired units,but also protecting the environment and making comprehensive utilization of flyash.Currently pneumatic ash handling system is the commonly used methods ofash in thermal power plant.The practical application of fluidized technology usesthe kinetic energy of the fluid, transporting the particulate material along the flowdirection in a sealed passage.Pneumatic conveying equipment has advantage ofthe simple structure and easy operation. In addition, it can handle the materials bythe mean of heating, cooling, drying, grading the airflow and the operation ofphysical or chemical in the process of transportation.In this paper, we take the engineering construction of ash handling system,which is used to3X626MWCoal-fired power plants, as the research background.We analyzes the whole process of the pneumatic ash handling system, theworking process of each subsystem and factors which influence the effect.Gasification blower system is mainly studied. The conclusion is that heater outlettemperature is a big delay of the object and the temperature control is particularlyimportant to the stability of the pneumatic ash handling system in the economicoperation.Through a large number of relevant literature and field actual research,the dynamic matrix control algorithm (DMC) is designed, which to control thetemperature, according to the size deviation, the influence of the precision ofcontrol system. Through the analysis of system structure and system reliability, hardwaresystem is designed by the controller ofRX7i, RX3i, which are from the GEcompany of America.Selecting GE’s IFIX4.0configuration software to thereal-time monitoring and control the ash removal equipment.Through the actualoperation proves that the design of ash control system is reliable operation, goodman-machine interaction, easy to operate, and improve the automation level ofthe whole plantmachine in this paper.In order to achieve control functions completely and control of temperatureprecisely, this paper combines the simulation and actual operation of the system,the temperature control system is designed based on PLC, dynamic matrix controlalgorithm (DMC) implemented in the PLC. Through the tests show that thesystem meets the expectations of the technical requirements, the temperaturecontrol system control the electric heater outlet temperature quickly andaccurately. The result of simulation experiment and debugging operation showthat the control effect of the whole control system of pneumatic ash reachedexpectations, the system can achieve stable operation.