Carbon monoxide removal device and medium-temperature SCR (Selective Catalytic Reduction) system

The invention discloses a carbon monoxide removal device, which comprises an SCR reaction part; the ammonia spraying part is communicated with the upstream of the SCR reaction part in the flowing direction of the flue gas, so that the ammonia gas and the flue gas enter the SCR reaction part after being mixed; the carbon monoxide reaction part is communicated with the upstream of the ammonia spraying part in the flowing direction of the flue gas and comprises a carbon monoxide reaction gas path and a flue gas bypass, the carbon monoxide reaction gas path and the flue gas bypass are connected in parallel, and the carbon monoxide reaction gas path is provided with a carbon monoxide catalyst for removing carbon monoxide in the flue gas. When the carbon monoxide removal device provided by the invention runs, the carbon monoxide reaction gas path removes carbon monoxide in flue gas, and when the carbon monoxide catalyst needs to be replaced, the carbon monoxide reaction gas path can be closed, and the flue gas is c