A numerical study on the combustion process for various configurations of burners in the novel ultra-supercritical BP-680 boiler furnace chamber

•The novel ultra-supercritical boiler BP-680•The coal combustion with OFA nozzles was CFD investigated.•The modification of the Burners was CFD investigated.

This paper presents preliminary results of numerical investigations into the combustion process in the BP-680 boiler furnace chamber with swirl burners placed on the furnace front wall. The calculations were performed using the ANSYS FLUENT commercial code. The swirl burner operates with the secondary air swirl angle of 50°. The boiler is supplied by outermost sets of mills – the mills and either the bottom or the upper burners. A proposal is made to change the secondary air swirl angle to 45°. Therefore, four cases of the furnace chamber operation are simulated: the furnace is supplied by either the bottom or the upper burners with the secondary air swirl angle of either 50° or 45°. It is found that a reduction in the secondary air swirl angle in the burner from 50 to 45° extends and carries the flame away from the waterwalls. Comparative charts of CO and O2 contents in flue gases, of the flue gas temperature and of the heat flux along the height of the furnace chamber for the four cases under analysis are presented.