具烟气再热器的FGD系统初投资、运行、维护费用高昂,取消烟气再热器,采用湿烟囱排放,虽然具有最低总费用优势,但是会带来烟气扩散和烟羽不透明,防腐材料要求高、易损坏,烟囱积水等问题,介绍了2种新的排烟方法,提高了FGD运行的安全性和经济性。“,”Flue gas desulfur（FGD） systems with flue gas reheater have high cost in early investment,operation,maintenance.Although canceling the flue gas reheater and using wet chimney emissions had the lowest total costs,but would bring some problems,such as the flue gas diffusion,plume opacity,using high cost anti-corrosion materials,the equipments easily damaged,waterlogging in chimneys and so on.To introduce two kinds of new extraction methods which can improve the safety and economy of FGD.