Study on Combustion Characteristics and Ignition Performance of a Reverse Pulverized-Coal Flame Stabilizer

The rapid growth in the installation of new energy poses challenges to the stability of the power grid due to its volatility and intermittency. Coal-fired power plants have come to play an important role in flexible peak power regulation. Considering that the burner is the core of a pulverized coal boiler, this study proposes the application of reverse injection pulverized coal combustion technology to power plant burners to achieve better ignition and combustion stability. The results of numerical simulations combined with experimental verification indicate that for a single ignition stabilizer, recirculation zones can be formed on both sides of the primary pulverized coal pipe at the front cone, and a high-temperature flame is ejected at high speed at the outlet. As the secondary air temperature increases from 373 K to 533 K, the axial length of the high-temperature recirculation zone increases, corresponding to an increase in the average outlet flame temperature from 1510 K to 1672 K. Under different loads of the main pulverized coal burner, the high-temperature flame ejected from the stabilizer can quickly encounter and mix with the surrounding main pulverized coal airflow, thereby igniting it rapidly. This process establishes a high-temperature flame zone within the two-stage combustion chamber, demonstrating strong adaptability to load fluctuations. As the burner load decreases, the outlet airflow velocity decreases significantly and the high-speed zone area shrinks, and the two adjacent high-temperature zones initially formed at the outlet gradually merge into a larger high-temperature zone. Simultaneously, the upward deflection of the jet at the outlet weakens.