Design And Implementation Of Circulating Fluidized Bed Boiler Denitration System In Shanghai Petrochemical Company

China Shanghai petrochemical Limited by Share Ltd (hereinafter referred to as spc), is located Jinshan District in Shanghai, area covered about nine point four square kilometer, and it is one of the largest enterprises which is refining chemical integration, highly integrated petrochemical in current china, and it is an important base for developing modern petrochemical industry in china.7# furnace in SPC thermal power plant is a 620t/h circulating fluidized bed (CFB) boiler, which is a natural circulation boiler developed and designed by shanghai boiler factory. The amount of flue gas is 590000 NM3/h (Dry basis、6%O2), the initial emission concentration for NOx is 250mg/Nm3(accounted by NO2、Dry basis、6%O2). However, based on《The standard of atmospheric pollutant discharge in thermal power plant》 (GB 13223-2011):from July 1st in 2014, the discharge limit value for Circulating fluidized bed coal-fired boiler nowadays is 100mg/Nm3 (Key areas). Emission concentration of NOx for 7# furnace has exceed the 100 mg / Nm3, it faces the expressure of flue gas denitrification, so it needs to do the government of furnace flue gas denitrification so that it can satisfy the more strict environmental protection and enterprise development requirement, and make sure The nitrogen oxide in furnace emission of flue gas can be Standard in discharge.In this paper, from the performance unstardard of 620t"h-l circulating fluidized bed boiler efficiency and NOx emission concentration, it analysis furnace heat loss and the law from emission concentration and average bed temperature parameters, and obtain that the main factors for exceeding the NOx emission concentration and low furnace effiency is the heat loss of exhaust gas and solid incomplete combustion loss too large、the high average bed temperature、fluidization quality decrease which caused by hood abrasion.Based on above viewport, it propose the improvement thinking of how to increase the air preheater heat absorption, how to descrease the bed temperature, how to improve the fluidization quality, from the analysis of thing improvement, it obtained the detail improvement measures-rotary air preheater retrofit、extended water screen、screen type superheater and hood retrofit. From analysis the improvement parameter, it obtained the possibility of encounter problem which caused by hot air pipe wear and the movement of dense phase zone.Finally it realize the target of NOx emission reduction and boiler efficiency using the improvement denitration system of circulating fluidized bed boiler exchanger in SPC thermal power plant。...