What factors limit further reduction of the boiler exhaust gas temperature?
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This post was last edited by zgj2405 on 2011-7-20 18:09. What factors limit further reduction of the boiler exhaust temperature?
This post was last edited by zgj2405 on 2011-7-20 at 18:10. Acid dew point temperature: The temperature is too low, causing corrosion of the hot surfaces at the tail end
Regarding the second floor: additional information on that floor, as well as the economic viability of equipment investment and recovery
Reducing the flue gas temperature can minimize heat losses from the flue gases and improve the thermal efficiency of the boiler. Currently, the designed flue gas temperature for typical power plant boilers is around 110–160. Why can’t it be reduced further? The following two aspects are primarily considered: (1) A low flue gas temperature can cause low-temperature corrosion of the heated surfaces at the rear; therefore, when burning coal with high sulfur and moisture content or heavy oil, it is not advisable to use excessively low flue gas temperatures ； (2) The flue gas temperature is low, which reduces the heat transfer temperature difference across the heating surfaces at the rear of the boiler. To transfer the same amount of heat, a larger heating surface area is required, resulting in increased consumption of boiler metal. The ventilation resistance of the boiler as well as the electrical power consumption of the fans also increase. Additionally, the overall size of the boiler increases, posing certain difficulties in terms of layout. An appropriate flue gas exhaust temperature is determined through technical and economic comparisons, based on the heat loss from the flue gases and the cost associated with the wear of the heating surface metals.