| As China develops,traditional coal-fired industrial boilers are no longer suitable for its development in a new era.In recent years,China has further strengthened the treatment of coal-fired industrial boilers;not only higher standards for boiler pollution emissions are set,but also requirements for the capacity of coal-fired industrial boilers are made.In order to adapt to the trend of coal-fired industrial boilers with high efficiency,low emission and large capacity,the research group and the enterprise have cooperated to research and develop a 35t/h high-efficiency and low-NOx double-furnace pulverized coal fired industrial boiler on the basis of present accumulation of technology and experience.In order to combine the needs of the enterprise itself and for a better adaptation to industrial production,this pulverized coal fired industrial boiler was designed as a double furnace structure.The furnace is arranged in parallel on the left and right,sharing a water wall in the middle.In order to be more suitable for industrial production,it is designed as a double furnace structure.The furnace is arranged in parallel on the left and right,sharing a water wall in the middle.The left and right furnaces are respectively equipped with a 20t/h and15t/h burner.Each hearth forms two independent combustion and heat exchange systems with the corresponding burners and heat exchange surfaces,numbered as furnace A and furnace B.Furnaces A and B can be operated independently,giving them a strong load regulation capability.This newly-built boiler marks the first application of such type of machine in China,relevant reports and materials are lack.This article analyzed and discussed the boiler`s structure,debugging process,operation status and fractions to be improved.Firstly,this article introduced the main structural features of the boiler and the boiler system composition;the layout of the its structure,dual furnace structure,boiler steam and water circulation and main design parameters were introduced and explained.The boiler system’s pulverized coal fired supply system,low NOx burner,boiler air flue gas water vapor system,desulfurization system and ash slag system were introduced.Secondly,the technical essentials and specifications of the pulverized coal fired supply system debugging,boiler auxiliary equipment debugging,burner ignition debugging,oven,boiler,boiler tightness test,safety valve setting,and boiler trial operation were introduced.Through debugging,the problems left in the installation and manufacturing process of the boiler could be found,and the problems in the debugging process could be analyzed and solved to ensure safe and stable operation of the boiler and meet the industrial production.Then,its operating conditions during the commercial operation of the boiler were analyzed.The operating data of the boiler showed that the boiler has strong load regulation capability and flexible load distribution between the two furnaces.Through optimized air distribution test,the relationship between NOx and CO emissions and flue gas oxygen content was studied and analyzed.The test results showed that the best boiler operating conditions occurred when the flue gas oxygen content was controlled at 2% to 4%.By observing the slagging situation of the boiler,the slagging situation of the boiler is mainly divided into five kinds,the reasons for the formation of these five kinds of slag are analyzed,and the influence of the coal quality and the operating conditions of the burner on the slagging of the boiler is also analyzed.Measures to prevent slagging of the burner are given.Through the energy efficiency test,the output and heat loss of the boiler under the rated working condition are obtained.The test results showed that the boiler reached90.88%.Finally,according to the research and analysis of the negative pressure imbalance of the double furnace during the operation of the boiler,it is concluded that its single flue exhaust system is the main cause of the negative pressure imbalance of the double furnace.When the load and heating of the two furnaces and the area-dust level differentiate,the flue gas flow rate and the flue gas flow resistance change respectively,so that the energy of the two furnaces at the flue confluence is not equal to the two furnaces,which results in the difference in the negative pressure of the two furnaces.balance.At the same time,based on the above reasons,the improvement measures of the boiler smoke exhaust system are given.The single flue structure is changed to an independent double flue structure,so that the negative pressure adjustments of the two furnaces are independent of each other,and the negative pressure balance of the double furnaces is realized. |
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