Flue gas dew point is the key indicator of low temperature corrosion

and restricts deep utilization of boiler flue gas heat. Fouling of heat exchanger surface is a major factor in deterioration of heat transfer. When fluid flows across heat exchange tubes

fouling and acid condensation influence heat transfer of heat exchanger. In the flue gas environment with dust and acid

a hot-state test was conducted to analyze heat transfer characteristics at different outer wall temperatures

and the dew point of flue gas for engineering application was obtained with a higher use value. The influence of the tubes' heat transfer characteristics with varying fouling and acid condensation was determined. Ash deposition with different amounts of acid condensation was investigated through analyzing the ash samples at different outer wall temperatures. The value of applied dew point for engineering was given as 72℃

which was at least 35℃ lower than the acid dew point in thermodynamics.