Working principle of split flame burner

Working principle of split flame burner

Nitrogen burner classification burners are important equipment on industrial fuel oil boilers and gas boilers. It ensures the stable combustion of fuel and complete combustion of fuel. Therefore, to suppress the amount of NOx generated, you must start with the burner. According to NOx-reducing combustion technology, low-NOx burners are roughly divided into the following categories:

1. Stage burner

The stage burner designed according to the principle of staged combustion allows the fuel and air to be mixed and burned in sections. Since the combustion deviates from the theoretical equivalence ratio, the generation of NOx can be reduced. 2. Self-recycling burner

One is to use the pressure head of combustion air to suck back part of the combustion flue gas, enter the burner, and mix with the air to burn. Due to the flue gas recirculation, the heat capacity of the flue gas is large, the combustion temperature is reduced, and the NOx is reduced. Another self-recycling burner is to put part of the flue gas directly into the burner for recirculation and add it to the combustion process. This kind of burner has the dual effects of suppressing nitrogen oxide and saving energy.

3. Intensive burner

The principle is that part of the fuel is burned too rich and the other part is burned lightly, but the overall air volume remains unchanged. Since both parts are burned at a deviation from the stoichiometric ratio, the NOx is very low. This kind of combustion is also called deviation combustion or non-stoichiometric combustion.

4. Split flame burner

The principle is to divide a flame into several small flames. Due to the large heat dissipation area of ​​the small flame and the low flame temperature, the "thermal reaction NO" has decreased. In addition, the small flame shortens the residence time of oxygen, nitrogen and other gases in the flame, and has a significant inhibitory effect on "thermal reaction NO" and "fuel NO".

5. Mix-promoting burner

The residence time of the flue gas in the high temperature area is one of the main factors that affect the amount of NOx generated. Improving the mixing of combustion and air can reduce the thickness of the flame surface. When the combustion load is constant, the flue gas is high temperature on the flame surface The residence time in the area is shortened, thereby reducing the amount of NOx produced. The mixing-promoting burner is designed according to this principle.

6. Low NOx pre-combustion chamber burner

The pre-combustion chamber is a high-efficiency, low-NOx staged combustion technology developed and researched in China in the past 10 years. The pre-combustion chamber is generally composed of primary air (or secondary air) and fuel injection system. The fuel and primary air are rapidly mixed. A fuel-rich mixture is formed in the primary combustion zone of the precombustion chamber. Due to lack of oxygen, only part of the fuel is combusted. The fuel precipitates volatiles in the primary flame zone that is lean in oxygen and has a low flame temperature, thus reducing the generation of NOx.