Selective catalytic reduction denitration method and selective catalytic reduction denitration system

The invention discloses a selective catalytic reduction denitration method and a selective catalytic reduction denitration system. The method comprises the following steps: atomizing ammonia water (forming ammonia gas) by utilizing an ultrasonic generator, mixing the mist-type ammonia water (ammonia gas) with smoke containing nitric oxide, and reducing the mixed smoke to nitrogen and water in the existence of a catalyst. The selective catalytic reduction denitration system comprises a smoke inlet channel and a selective catalytic reduction denitration device, wherein the smoke inlet channel is provided with at least one ultrasonic generator, an ammonia water inlet of the ultrasonic generator is communicated with an ammonia water source through an ammonia water pump, and an ammonia water atomizing hole of the ultrasonic generator is arranged in the smoke inlet channel. According to the method and system, the ammonia water molecular structure can be scattered by utilizing electronic high-frequency vibration through the high-frequency resonance oscillation of an atomizing sheet in an ultrasonic atomizing way, the natural drifting mist is generated, no heating or chemical reagent is needed, ammonia gas can be formed without consumption of heat energy, and the ammonia gas and the smoke can be adequately mixed.