Low nitrogen retrofit method of gas boiler burner

Low nitrogen retrofit method of gas boiler burner
Natural gas boiler is the most widely used boiler product after coal-fired boiler, and is also the current mainstream product. Gas is natural gas, liquefied gas, gas and biogas in the combustion process. Natural gas boiler is widely used, so people call it natural gas boiler. According to the new environmental protection law, air pollution equipment should be supervised, pollutant emissions should be strictly restricted, blue water and blue sky projects should be implemented, and biomass briquette or natural gas should be recommended. Governments at all levels will take corresponding measures to implement the plan of transforming coal-fired boilers into gas-fired boilers. Natural gas is a kind of clean fuel. It burns well and produces less ash, sulfur and nitrogen than coal. At the same time, pipeline transportation of gaseous fuel can greatly reduce labor intensity, improve labor conditions and reduce operating costs. The implementation of national "West-East Gas Transmission" and other projects has provided high-quality, sufficient and cheap gas sources for the scheme of transforming coal-fired boilers into gas-fired boiler burners.
The nitrogen oxide content in the tail gas emission of gas-fired boiler is more than 150 mg per cubic meter, while the standard is less than 80 mg or 30 mg. Those with low nitrogen of 80mg are called low nitrogen gas boilers, and those with less than 30mg are called ultra-low nitrogen gas boilers.
How to carry out low nitrogen transformation for ordinary gas boiler?
1、 The main body is changed to boiler main body, namely boiler main body. Through reforming the furnace and heating area, we can make the gas-fired boiler burn more fully, further reduce the nitrogen oxide content in the flue gas, and finally achieve the goal of low-nitrogen gas transformation.
2、 The method of low nitrogen transformation of gas-fired boiler is generally based on burner transformation. The low nitrogen burner is replaced to make its performance more energy saving, environmental protection and efficient, so as to reduce the content of nitrogen oxides in the boiler tail gas. It is usually divided into low nitrogen burner and ultra-low nitrogen combustion. The transformation methods of low nitrogen burner of gas boiler include:
1. Use the pressure head of combustion air to suck back a part of the flue gas after combustion, enter the burner, and mix with air to form flue gas recirculation. Due to the recirculation of flue gas, the heat capacity of combustion flue gas is large, the combustion temperature is reduced, and the content of nitrogen oxide is reduced. Another kind of self-recirculation burner is to directly enter part of flue gas into the burner and add it into the combustion process. This burner has the dual functions of environmental protection and energy conservation.
2. Full premix burner (surface combustion) Full premix combustion technology is to fully premix combustion gas and air before entering the combustion chamber, so as to make combustion more fully, improve combustion efficiency, reduce harmful gas emissions, and reduce the space demand of the combustion chamber. This is the first advanced gas combustion technology in the world at present.
The low nitrogen transformation methods of gas boiler are mostly the above two. We usually use the low nitrogen transformation of burner, which is usually applicable to small gas boiler products. The low nitrogen transformation of large gas boiler needs the furnace and burner to be carried out at the same time, and the boiler body and burner are matched to work efficiently.