The invention discloses an efficient SCR (
Selective Catalytic Reduction) denitration device of a gas
turbine unit and a denitration method. The device comprises a flow velocity measuring device, an
ammonia water spraying device, a
flue gas rectifying device and a catalyst layer, the flow velocity measuring device and the
ammonia water spraying device are sequentially arranged at the upstream of the
flue gas pipeline, probes of the flow velocity measuring device and nozzles of the
ammonia water spraying device are uniformly distributed on different cross sections in the
flue gas pipeline, and the probes and the nozzles are matched in number and position; the
flue gas rectifying device is arranged in the middle and downstream of the
flue gas pipeline and in front of the multi-stage
heat exchanger, and the
spiral flow of
flue gas is converted into linear uniform flow along the flue gas channel; the catalyst layer is arranged in the flue
gas pipeline and located between the
multiple stages of heat exchangers. According to the characteristic that flue gas discharged by the gas
turbine spirally flows, the ammonia water injection amount is adjusted through multi-point flow
velocity measurement, spiral flowing is converted into linear flowing through the flue gas rectifying device, the uniformity degree of
mixed gas is improved, full
catalysis is achieved, and then efficient denitration is achieved.