NO2 emission control system and method for gas turbine combined cycle units in starting process

The invention relates to a NO2 emission control system and method for gas turbine combined cycle units in the starting process, and belongs to the field of gas turbine power generation. The control system comprises a gas turbine compressor, a gas turbine combustor, a turbine of a gas turbine, a waste heat boiler, a turbine exhaust temperature measuring device, a waste heat boiler inlet temperaturemeasuring device, a boiler exhaust CO measuring device and a spraying device; and the gas turbine compressor, the gas turbine combustor, and the turbine of the gas turbine are sequentially connectedwith the waste heat boiler, the turbine exhaust temperature measuring device is arranged at a turbine exhaust outlet of the gas turbine, the waste heat boiler inlet temperature measuring device is arranged at an inlet of the waste heat boiler, the boiler exhaust CO measuring device is arranged at a smoke exhausting position of the waste heat boiler, and the spraying device is arranged in a turbineexhaust outlet flue of the