Study On Application Of High Efficiency Desulfurization Technology Of300MW CFB Boiler

Circulating fluidized bed （CFB） boiler furnace is widely due to good performance ofthe economy and fuel desulfurization adaptability advantages are widely used. Due to thepresence of limestone injection desulfurization material cycle low magnification，high bedtemperature，low sorbent utilization（usually within the range of20%-45%），limestoneconsumption and other shortcomings，leading to its desulfurization efficiency is not high. It isnecessary to have the domestic CFB boiler power plant and take technology reasonable,economically feasible, suitable for the actual conditions of power plant desulfurizationprocess, the research on how to improve the method of CFB boiler calcium utilization,reduction of pollutant generation and discharge to a large extent, effectively reduce emissionsof sulfur dioxide and soot, on Protect environment to ensure the realization of ‘the12th FiveYear Plan’, the goal of energy saving and emission reduction, the promotion of resourceconservation, the environment friendly society construction, have very important sense.In this paper, in order to determine300MW CFB boiler furnace spraying calciumdesulfurization desulfurization efficiency, actual effect on the actual operation of a ganguepower plant of CFB boiler were tested and analyzed, the results show that the desulfurizationefficiency is not high, and the concentration of sulfur dioxide emissions fluctuation is biggeralso, even more limestone powder can not meet the require ments of the latest environmentalprotection standard.Based on the300MW CFB boiler furnace calcium injection desulfurization efficiencyresearch, theory is generally believed that, in the furnace temperature of850℃-900℃, Ca/Smolar ratio in the1.5-3.0range, limestone powder particle size is smaller than2mm （usually 0.15mm-0.5mm）, up to85%-90%in the furnace desulfurization rate. But found in the actualtest, due to low circulation ratio, bed temperature is higher, lime particle pore blockage, sothat the desulfurization efficiency of the furnace and is not too high, Even for modification ofthe desulfurization system, concentration of sulfur dioxide emissions could not reach therequirements of the latest environmental protection. therefore, only using the furnace calciuminjection desulfurization is difficult to meet the requirements of the latest environmentalemission standards.The gambit numerical simulation software of CFB boiler flue at the tail of theestablished physical model, using FLUENT software, simulation of gas-liquid two-phaseflow in the flue at the tail of the flow, spray gun in three kinds of pressure of0.1MPa,0.15Mpa,0.2MPa atomized water sprayed into, bending the tail flue gas liquid two phaseflow in a mixed state, track and atomized water droplets in the flue distribution characteristicsare analyzed. Research shows that in the CFB boiler flue gas sprayed into a certain amount ofatomized water, the nozzle inlet pressure0.2MPa, in the region of water atomization, themixing state of the flue gas and the atomization water better, to extend the effective and fluegas and fly ash calcium oxide hybrid collision time, can fly ash, unreacted calcium oxidespray water humidification activation, the distribution of flow field on the desulfurizationefficiency is improved, reducing desulfurization cost and operation cost are significant.Therefore, this paper chooses a method to make full use of flue ga s, unreacteddesulfurizer-300MW CFB boiler furnace high temperature desulfurization and flue at thetail of the low temperature spray humidification desulphurization method combining highdesulfurization technology for CFB Boiler in a more cost-effective way of desulfurizationoperation. Test data show that in230MW to load and265MW range, through to in the flue atthe tail of the direct water spray humidification activation desulfurization, nozzle pressure inthree cases of0.1MPa,0.15Mpa,0.2MPa, flue gas emission concentration can meet therequirements of the latest environmental standards, which with the atomizing nozzle of thesimulation have great relationship, with the increase of nozzle pressure, good atomization state, droplet diameter, and the inner part of a flue residence time is relatively extended,which are conducive to the mixture of reaction, a full description of the the technology isfeasible, and then verify the accuracy of the numerical simulation of CFB boiler tail flue.The research results show that300MW CFB boiler furnace spraying calciumdesulfurization and tail flue of spray water combined desulfurization technology is feasible, isto meet strict environmental standards and effective way in the future. Through the analysisof the research on the subject for the future of large CFB boiler desulfurization solutionformulation and implementation has important guiding significance.