Method for conducting combustion in a furnace in order to limit the production of nitrogen oxides, and installation for implementing said method

A facility comprising:

• a fluidized bed combustion furnace, according to which a flow of combustion primary air is blown through the bed, the fuel including one or more of organic waste, of municipal waste, and of sludge from purifying plants, wherein secondary air is injectable into the space in the furnace located above the bed;
• means for measuring, at the furnace outlet, the nitrous oxide N2O and nitrogen oxides NOx content of the flue gases;
• a regulating unit, comprising a PID controller which is configured with an algorithm for limiting the production of nitrous oxide N2O;
• an input for a bed set-point temperature in the algorithm, the regulating unit being configured to correct the set-point temperature in response to the nitrous oxide N2O content of the flue gases,
• a means for measuring the temperature of the bed, the measured value being introduced into the regulating unit,
• in order to control the production of nitrogen oxides NOx, a means for controlling excess air by action on the flow of primary air passing through the bed, while taking into account a correction function f(NOx) according to the nitrogen oxides NOx content of the flue gases at the post-combustion outlet, the NOx-controlling action being limited by the difference in temperature (ΔT) between the bed and the post-combustion, in order to ensure staging of the combustion of the devolatilized hydrocarbons,
• said regulating unit determining, on the basis of the difference between corrected set-point temperature of the bed and measured temperature of the bed, the action to be carried out on the temperature of the combustion air, and/or on the siccity of the fuel, and/or on an optional addition of fuel, in particular of fuel oil, so as to ensure the corrected set-point temperature.