FEATURES OF THE INFLUENCE OF RECIRCULATION OF COMBUSTION PRODUCTS ON THE FORMATION OF NITROGEN OXIDES IN BOILERS DURING BURNING NATURAL GAS

Abstract

During the combustion of natural gas and the supply of exhaust gases recirculation like a ballast was shown. It is necessary to take into account that they contain nitrogen oxides, mainly in the form of NO, which does not decompose in the combustion zone, but is added to nitrogen oxides that has been produced during burning of fuel. The combustion products are affordable, but not ideal ballast. As on the one side, they reduce the maximum temperature in the combustion zone and the concentration of reagents, i.e. reduces the formation of «thermal» NOx, on the other side, they add to the combustion zone an additional amount of nitric oxide, which is summed up with that has been formed during burning in the combustion chamber and also reducing the efficiency of the method. When the maximum temperature in the combustion zone is the highest and the entire volume of fuel and ballast before to the combustion is best mixed during recirculation of exhaust gases, their effect on the formation of nitrogen oxides is the highest. The most effective ballast that reduces the formation of NO during combustion is carbon dioxide, provided it is well pre-molecularly mixed with natural gas before to the combustiontion zone. Bibl. 16, Tab. 4, Fig. 2.