FIELD: power industry.
SUBSTANCE: method of combustion process in combustion plants, in which fuel is supplied to the grate of combustion plant, gas for primary combustion is introduced through fuel, and gas for secondary combustion, which contains ambient air, is introduced through atomisers immediately to exit gas flow above fuel; at that, some portion of exit gas is taken from exit gas flow in rear area of grate and again supplied to combustion process as internal recirculation gas; at that, sum of the amount of gas for primary combustion and amount of gas for secondary combustion is reduced so that stoichiometric reaction conditions are essentially reached in relation to exit gas flow immediately above gas plane for secondary combustion; at that, penetration of internal recirculation gas to secondary combustion area is prevented and internal recirculation gas is supplied to tertiary combustion area; at that, exit gas has delay time at least for one second after gas introduction for secondary combustion. Gas for secondary combustion includes ambient air and external recirculation gas which passes through steam generator. Gas for secondary combustion includes external recirculation gas which passed through steam generator. Chemical agent for reduction of nitrogen oxides is sprayed in supply area of internal recirculation gas, i.e. in tertiary combustion area. Agent for reduction of nitrogen oxides is mixed to gas for tertiary combustion, i.e. to internal recirculation gas. Carbamide or ammonia is used as chemical agent. Increased turbulence of exit gases is created in tertiary combustion area or above it, i.e. above introduction of internal recirculation gas.
EFFECT: invention allows reducing NOx in combustion products.
10 cl, 1 dwg
