The status quo of abolishing by-pass flue duct in wet flue gas desulphurization(FGD) system at home and abroad has been described

the factors affecting the abolishing by-pass flue duct in wet FGD system being analysed

and a technical scheme of abolishing by-pass flue duct in wet FGD system being put forward.The economic efficiency analysis of desulphurization for 2×300 MW units

2×600 MW units

and 2×1 000 MW units shows that the abolishment of by-pass flue duct in single tower technology and in double tower technology for GFD will increase capital investment by 3%~10% and 10%~15% respectively.The capital investment for double tower technology is about 5% more than that in single tower scheme.After abolishing the by-pass flue duct in three power plants

the electricity consumption in operation can be reduced by 1.5 million kW·h

2.5 million kW·h

and 3.25 million kW·h respectively

the cost of operation in FGD system can be saved by 0.45

0.75

and 0.98 million yuan respectively

and the maintenance expense can be decreased by a big margin.