Fuel desulfurization and denitrification system

The utility model discloses a fuel desulfurization and denitrification system which comprises a circulating fluidized bed boiler, a gas preheater, a gas concentration mixer, a first desulfurizer bin and a second desulfurizer bin, the circulating fluidized bed boiler comprises a hearth and a cyclone separator communicated with the hearth, the hearth is provided with a feed port and a first gas inlet, and the cyclone separator is communicated with the feed port. The gas concentration mixer is provided with a primary air pipe and a secondary air pipe, the primary air pipe is communicated with thefirst air inlet, the secondary air pipe is divided into a secondary shunt air spray pipe and a tertiary air spray pipe which are both communicated with the hearth, and a first spray head and a secondspray head are respectively arranged at the end parts in the hearth in a downward inclined manner; and the second nozzle is higher than the first nozzle. The system disclosed by the utility model canbe used for efficiently de