Flue gas recirculation (FGR), which can regulate the heat transfer characteristics of double-reheat boilers, has received widely attention. The effect of FGR on heat flux distribution and heat absorption on heating area was investigated by numerical simulation based on a 660 MW tower-type double-reheat boiler. The results showed that when the FGR ratio increases, the heat flux in boiler ash hopper are decreased, and the area with high heat flux (260-330 kW m-2) is reduced. The heat absorption in water-cooled wall zone is decreased, while that of reheater, superheater and economizer zone is increased once the RFG ratio increases.
Keywords Flue gas recirculation, heat transfer characteristics, heat flux distribution, numerical simulation, double-reheat boiler