Research Progress on the Stable Operation of Pulverized Coal-Fired Boilers under Low-Load Conditions

The increasing proportion of new energy sources has put forward higher requirements for the peak-shaving capability of coal-fired power generation units. The paper reviews research progress on the combustion characteristics and stable operation technologies of pulverized coal furnaces under low-load conditions. Notably, low-load operation induces two critical challenges: reduced combustion temperatures and shortened fuel residence times, which directly lead to decreased combustion efficiency and poor flame stability. To address these issues, we summarized two core stable combustion technologies. First, collaborative optimization of burner structure and secondary air ratio enhances heat reflux and fuel-air mixing under low-load conditions, thereby moderately improving the combustion stability of pulverized coal furnaces. Second, cofiring of pulverized coal with gaseous fuels not only significantly accelerates coal particle ignition (via highly reactive gaseous fuels) and strengthens pulverized coal combustion but also effectively reduces pollutant emissions when using clean gaseous fuels. Collectively, these technologies offer feasible solutions to enhance the low-load stability of pulverized coal furnaces, supporting coal-fired power units to meet growing peak-shaving demands amid the global energy transition.