Study On Control Mode Of Dust Removal System In Power Plant

The dust removal system of thermal power plant is an important part of the production process,which can control the concentration of industrial dust emission and meet the requirements of environmental assessment.With people’s attention to environmental protection,bag type dust collector has been widely used by virtue of its high dust removal efficiency,and the dust collected by the dust collector can be uniformly transported by the subsequent dry dust removal method.However,the coal quality,load and filter bag conditions are changing in actual production and operation,so further research is needed to make the dust removal stable and safe.This thesis takes a 350 MW unit as the research object and studies it according to the actual demand of dust removal.The dust removal system belongs to the auxiliary control network of the power plant.It is controlled by PLC and controlled by the centralized control room operator station finally through the Ethernet composed of optical fibers.The bag type dust collector uses pulse solenoid valve to blow compressed air and shake off dust,and the way of dust removal is pneumatic dust removal.This thesis analyses the main on-site dust control equipment,makes the two work in different stages in the bag filter and dust removal control through the number of steps,the study uses Allen Bradley’s Logix5000 controller series and selects the appropriate component module,the program of dust removal control is completed by ladder diagram,mainly using differential pressure mode and time mode dust removal.According to the actual operation data,the wear condition of filter bag is analyzed,and the limit of mixing ratio is drawn up,so that the dust removal equipment runs stably and each monitoring value is in a reasonable range.In view of the current application environment in which a large number of coal blending is used in thermal power plants,this thesis completes the research from the perspective of thermal engineering in power plants.Through a series of practical operation observations,the dust removal system can work stably:With the step number,the differential pressure can be stabilized below the design value,the dust collected can be transported in time,the overall control is simple and intuitive,but also easy to maintain and repair,with a certain economy.In view of some special circumstances: after the filter bag aging,the mixing proportion should be controlled,the mixing amount should be controlled reasonably,and the filter bag should be replaced in time.