The Study on the Heat Transfer in Oxy-fired CFB

The influence of gases radiation on heat transfer coefficient was considered, and a model of heat transfer in oxy-fired CFB was set up. The model showed that the heat transfer coefficient was not changed greatly in oxy-fuel combustion, because the heat transfer was dominated by solids effects, which did not depend on the gas composition. Take a 440 t/h CFB as example, the size of CFB furnace under oxy-fuel combustion at the O₂ concentration of 30%, 50%, 70% was calculated. It was discovered that the higher O₂ concentration, the more necessary to set an external heat exchanger to keep the normal operation of the furnace.