Do you know the principle of boiler low-nitrogen transformation?
Writer： admin Time：2021-11-16 16:21 Browse：℃
Introduce the classification of low-nitrogen burners, the principle of low-nitrogen burners, and the characteristics of low-nitrogen combustion technology. Low-nitrogen burners and low-NOx burners refer to burners with low nitrogen emissions during the fuel combustion process and adopt low-nitrogen combustion. The device can reduce nitrogen oxides during the combustion process.
When the boiler is running under high load, the air volume of the blower is usually increased to increase the furnace temperature. At this time, the excess air coefficient is often large, and the furnace temperature is very high, resulting in a large amount of nitrogen oxides. Low-nitrogen combustion technology uses the pressure head of the combustion-supporting air to suck part of the combustion flue gas back into the burner and mix and burn with the air. Due to the recirculation of the flue gas, the heat capacity of the combustion flue gas is large, so that the combustion temperature is controlled at 1000 degrees, thereby reducing the generation of nitrogen oxides. In the flue gas internal circulation technology, part of the flue gas is directly recirculated in the burner, and added to the combustion process to control the combustion temperature, so that the concentration of nitrogen oxides is greatly reduced.
The pre-combustion chamber of the ultra-low-nitrogen combustor is an efficient, low-nitrogen staged combustion technology developed and researched in my country in the past 10 years. The pre-combustion chamber is generally composed of primary air (or secondary air) and a fuel injection system. Rapid mixing, a fuel-rich mixture is formed in the primary combustion zone of the pre-combustion chamber. Due to the lack of oxygen, only part of the fuel is burned. The fuel releases volatiles in the primary flame zone with low oxygen and lower flame temperature, thus reducing the generation of NOx. Any low-nitrogen combustion technology is essentially a technology to control the combustion process. Ultra-low nitrogen burner refers to a burner with low NOx emissions during fuel combustion. Conventional natural gas boiler burners usually emit NOx around 120~150mg/m3. The usual NOx emissions of ultra-low nitrogen burners are around 30-80 mg/m3. NOx emissions below 30 mg/m3 are usually called ultra-low nitrogen burners.
The principle of the ultra-low nitrogen burner is to divide a flame into several small flames. Due to the large heat dissipation area of the small flame, the flame temperature is lower, which reduces the "thermal reaction NO". 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". The residence time of the flue gas in the high temperature zone is one of the main factors that affect the amount of NOx generated. Improve the mixing of combustion and air, which can reduce the thickness of the flame surface. Under the condition of the combustion load unchanged, the flue gas is at a high temperature on the flame surface. The staying time in the zone is shortened, thus reducing the amount of NOx generated. The mixing-promoting burner is designed according to this principle.
The above is an introduction to the principle of boiler low-nitrogen transformation for you. If you want to know other content of low-nitrogen burners, please pay attention to Zhengzhou Bona Thermal Energy Equipment Co., Ltd.!