Refined control method for cold end temperature of air preheater in thermal power plant boilers

Abstract

This invention discloses a method for refined control of the cold end temperature of an air preheater in a thermal power plant boiler. During unit operation, when the sulfur content of the coal fed into the boiler flue gas flues, the real-time variation range of SO2 concentration in the flue gas generated by boiler combustion is divided into interval steps. The acid dew point temperature at the corresponding concentration is calculated. Through improved logic module configuration, the acid dew point temperature value corresponding to the upper limit of the SO2 concentration variation range is sent to the boiler air heater control system. This value is used as the control target value for the cold end temperature of the air preheater. The air heater control system automatically tracks and adjusts to ensure that the cold end temperature of the air preheater is never lower than the acid dew point temperature. This prevents sulfuric acid condensation in the flue gas from corroding and clogging the cold end of the air preheater when the flue gas temperature is below the acid dew point temperature, ensuring safe equipment operation, improving the economic efficiency of equipment operation, and further reducing coal consumption.

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