Coal-fired Boiler Flue Dust Removal Design And Economic Analysis

Taking an urban coal-fired heat-supply boiler as the research object,this study aims to have the boiler satisfy the state's emission standards after flue gas dedusting treatment.By means of studies on boiler body,main dedusting equipment,and duct dedusting design,in addition to monitoring on dust concentration varying with heating load during operation,this paper presents a reference as to future development of flue gas dedusting for coal-fired heat-supply boilers.Firstly,studies were conducted in terms of the heat source.The amounts of gas volume of different types of coal-fired boilers were calculated theoretically and compared with the parameter in actual production.The advantages and disadvantages of different types of boilers were given on the bases of their combustion efficiency,coal type applied,capital cost,operation expenditure,etc.Secondly,studies were conducted in terms of the main equipment of flue gas dedusting.The dedusting effect,operation expenditure,capital cost,and engineering limitation of dust collectors with different mechanisms were analyzed and compared.In addition,complementary comments were given towards the data in an actual project.Thirdly,studies on flue duct dedusting were conducted as a preliminary dedusting means during flue gas transportation.Dust particles are separated taking advantage of inertial separation and filtering mechanism,which are realized through duct design.A duct design that is favorable for dust collecting was determined,and the increased flue gas resistance and the resultant additional operation expenditure were calculated and analyzed.In an actual project,retrofit was conducted in a local duct section,and the gas detections and operation expenditures before and after retrofit were compared.Based on the flue gas detection and data collection in some heat source plants during heat supply,this paper summarizes the operation mode favorable for reducing flue gas emission concentration in heating seasons by data analyses of emission with heating load as well as theory studies.