Low nitrogen burner usually refers to the burner with NOx emission of 30-80mg; Emissions below 30mg are usually referred to as ultra-low nitrogen burners; Ultra low nitrogen burners are usually based on the following technologies:

1. Electronic proportional regulation and oxygen content control technology to control oxygen content;

2. Fully premixed surface combustion technology reduces flame temperature and realizes full combustion;

3. FGR flue gas recirculation technology reduces flame temperature and oxygen content;

At present, burners on the market mainly include the following types:

1. Surface combustion ultra-low nitrogen burner: surface combustion ultra-low nitrogen burner can usually control nitrogen oxide below 30mg in the whole combustion range, which is simple to install and does not need flue gas recirculation pipe;

2. Staged burner: the staged burner can usually control NOx within 65 mg and the limit is about 40 mg in the whole flame range.

3. Staged ultra-low nitrogen Burner + FGR flue gas circulation technology:

The staged Burner + flue gas recirculation technology combines the advantages of the staged burner to control NOx and reduce the oxygen content of FGR. It can control NOx within 20mg in the whole combustion range and oxygen content within 3%, so as to greatly improve the combustion efficiency.