When operating at low loads

W-flame boilers may encounter various problems

such as low reheated steam temperature

which requires combustion adjustments and other measures. To solve these problems

numerical simulations are conducted to investigate the combustion adjustment of a W-flame boiler under low load conditions. In order to deal with the low steam temperature at low loads

the influence of the position of the recycled flue gas injection and the presence of wall-attached air on the velocity field and temperature field inside the furnace were analyzed. The research results show that introducing recycled flue gas into the furnace by extracting 16% of the total flue gas flow at the air preheater inlet increases the amount of flue gas and improves the convective heat transfer on the heating surfaces. Combined with adjusting the opening of the reheater flue gas baffle

this approach can solve the problem of low reheated steam temperature at low loads. Injecting recycled flue gas from the SOFA air nozzle into the furnace has a minimal impact on the temperature in the primary combustion zone

which benefits the stability of coal combustion at low loads. Introducing 40% of the recycled flue gas as wall-attached air from the side walls of the lower furnace can lower the temperature of the side wall flue gas and transform it into an oxidizing atmosphere

reducing the possibility of side wall coking and high-temperature corrosion.