The combustion characteristics of coal-fired power plant boilers co-firing ammonia and its impact on the boilers are reviewed

aiming to provide theoretical and practical basis for large-scale application of ammonia as an alternative fuel to coal. By systematically reviewing existing literatures

the study examines the fundamental characteristics of ammonia combustion

flame propagation

flame morphology

and their effects on heat transfer

heat surface safety

boiler efficiency

and exergy efficiency of coal-fired boilers. The study also explores combustion enhancement methods such as oxygen-enriched combustion

preheated combustion

and hydrogen-assisted combustion. The results indicate that

co-firing ammonia can mitigate issues like ash deposition

slagging

wear

and high-temperature corrosion on heating surfaces

but it increases the acid dew point of flue gas

potentially exacerbating low-temperature corrosion. Co-firing ammonia increases the irreversibility of the combustion process

leading to higher furnace losses

although oxygen-enriched combustion can mitigate these losses. While there is substantial research on ammonia co-firing with small molecule gaseous fuels

there is limited study on its co-firing with large molecule solid hydrocarbons like coal. The effect of ammonia blending combustion on boiler heat transfer

heating surface safety

and boiler efficiency is significant. The decrease in flame temperature

reduction in flue gas soots

and changes in flue gas composition can affect heat transfer efficiency and heating surface conditions. Attention should be paid to low-temperature corrosion and unburned ammonia emissions. Ammonia blending combustion is an effective low-carbon combustion technology

but its application in large utility boilers still faces many challenges. It requires further in-depth research on combustion mechanisms and practical application effects to optimize combustion equipment and improve system efficiency.