Further study of the gas temperature deviation in large-scale tangentially coal-fired boilers☆

Gas temperature deviation in upper furnace is an important but a less reported issue in large-scale tangentially fired boilers, since they endanger largely boilers operation. Simulations are conducted in this paper to study the deviation. Perfect agreement between the simulation results and key boiler design values and available site operation records indicates that the calculations are reliable. Based on the simulations, effect of some factors, including residual airflow swirling at furnace exit, super-heaters panels, coal particle trajectories and their combustion histories, on temperature deviations are studied in details. The most important cause and how it affects the temperature deviation are located. Two new methods, a nose on front-wall and re-arranged super-heater panels, are put forward unprecedentedly to alleviate the deviations.