Circulating fluidized bed flue gas desulfurization(CFB-FGD)process has been widely applied in recent years.However,high cost caused by the use of high-quality slaked lime and difficult operation due to the complex flo...Circulating fluidized bed flue gas desulfurization(CFB-FGD)process has been widely applied in recent years.However,high cost caused by the use of high-quality slaked lime and difficult operation due to the complex flow field are two issues which have received great attention.Accordingly,a laboratoryscale fluidized bed reactor was constructed to investigate the effects of physical properties and external conditions on desulfurization performance of slaked lime,and the conclusions were tried out in an industrial-scale CFB-FGD tower.After that,a numerical model of the tower was established based on computational particle fluid dynamics(CPFD)and two-film theory.After comparison and validation with actual operation data,the effects of operating parameters on gasesolid distribution and desulfurization characteristics were investigated.The results of experiments and industrial trials showed that the use of slaked lime with a calcium hydroxide content of approximately 80%and particle size greater than 40 mm could significantly reduce the cost of desulfurizer.Simulation results showed that the flow field in the desulfurization tower was skewed under the influence of circulating ash.We obtained optimal operating conditions of 7.5 kg·s^(-1)for the atomized water flow,70 kg·s^(-1)for circulating ash flow,and 0.56 kg·s^(-1)for slaked lime flow,with desulfurization efficiency reaching 98.19%and the exit flue gas meeting the ultraclean emission and safety requirements.All parameters selected in the simulation were based on engineering examples and had certain application reference significance.展开更多
基金supported by National Natural Science Foundation of China(52336005 and 52106133).
文摘Circulating fluidized bed flue gas desulfurization(CFB-FGD)process has been widely applied in recent years.However,high cost caused by the use of high-quality slaked lime and difficult operation due to the complex flow field are two issues which have received great attention.Accordingly,a laboratoryscale fluidized bed reactor was constructed to investigate the effects of physical properties and external conditions on desulfurization performance of slaked lime,and the conclusions were tried out in an industrial-scale CFB-FGD tower.After that,a numerical model of the tower was established based on computational particle fluid dynamics(CPFD)and two-film theory.After comparison and validation with actual operation data,the effects of operating parameters on gasesolid distribution and desulfurization characteristics were investigated.The results of experiments and industrial trials showed that the use of slaked lime with a calcium hydroxide content of approximately 80%and particle size greater than 40 mm could significantly reduce the cost of desulfurizer.Simulation results showed that the flow field in the desulfurization tower was skewed under the influence of circulating ash.We obtained optimal operating conditions of 7.5 kg·s^(-1)for the atomized water flow,70 kg·s^(-1)for circulating ash flow,and 0.56 kg·s^(-1)for slaked lime flow,with desulfurization efficiency reaching 98.19%and the exit flue gas meeting the ultraclean emission and safety requirements.All parameters selected in the simulation were based on engineering examples and had certain application reference significance.
