The invention discloses a dry denitration method and device for low-
flue-gas-flow high-concentration
NOx flue gas, and the method comprises the following steps: introducing
flue gas into a pipeline, arranging a reserved catalyst layer at the initial end of the pipeline, arranging
multiple stages of catalyst
layers in the pipeline at the rear end of the reserved catalyst layer, arranging
ammonia spraying grids on the reserved catalyst layer and the
multiple stages of catalyst
layers, and spraying
ammonia on the
ammonia spraying grids. Heat exchangers are arranged at the rear ends of other catalyst
layers except the last stage; when the
flue gas enters the pipeline, the
flue gas is heated to a
reaction temperature at the inlet of the pipeline,
ammonia gas is sprayed out through the ammonia spraying grid, so that the
flue gas and the
ammonia gas are subjected to a multi-stage reaction under the action of a catalyst when passing through the reserved catalyst layer and the multi-stage catalyst layer, and during the period, the
heat exchanger is used for heat exchange and
temperature control to maintain each stage of
reaction temperature at the
reaction temperature, so that denitration is realized. The method has the characteristics of high denitration efficiency, low ammonia consumption, simple equipment, controllable
system temperature, no
wastewater generation and the like.