Method for adjusting metal wall temperature deviation of high-temperature reheater of opposed firing coal boiler

Abstract

The invention provides a method for adjusting metal wall temperature deviation of a high-temperature reheater of an opposed firing coal boiler. The method comprises the following steps that flue gas components of an inlet flue section of an SCR system and metal wall temperature data of the high-temperature reheater are collected; the flue gas components of the inlet flue section of the SCR system are tested, and if opposed firing combustors in opposed firing combustion sets at the corresponding positions of low O2 content and high CO content are insufficient combustion positions in a hearth, the opening degree of secondary air doors outside the opposed firing combustors is turned up; if the opposed firing combustors in the opposed firing combustion sets at the corresponding positions of high O2 content and low CO content are sufficient combustion positions in the hearth, the opening degree of the secondary air doors outside the opposed firing combustors is turned down; and opposed firing over-fire air combustors in opposed firing over-fire air sets corresponding to the overtemperature point or the high point of the metal wall temperature of the high-temperature reheater are obtained, the opening degree of secondary air doors in the opposed firing over-fire air combustors are turned up, and the opening degree of central air of the opposed firing over-fire air combustors is turned up. According to the adjusting method, the positions of the overtemperature point and the high point of the metal wall temperature of the heating surface of the high-temperature reheater are adjusted and controlled, the thermal load deviation of the heating surface is reduced, and the reheating steam temperature is increased.

Description

technical field [0001] The invention belongs to the field of boilers, and in particular relates to a method for adjusting the temperature deviation of a metal wall of a high-temperature reheater of an opposing coal-fired boiler. Background technique [0002] Hedge coal-fired boilers are widely used in domestic 600MW and 1000MW units by virtue of their advantages in heating surface layout and combustion economy. With the large-scale transformation of low-nitrogen burners in domestic coal-fired power plants, the deep staged combustion technology of low-nitrogen burners has brought about problems such as the upward movement of the furnace flame center, combustion lag, and the increase in the smoke temperature of the horizontal flue, resulting in the boiler horizontal flue The heat absorption of heating surfaces such as high-temperature superheaters and high-temperature reheaters increases, and the metal wall temperature of the heating surfaces increases. Especially under high ...

AI Technical Summary

Problems solved by technology

Research on DCS control logic optimization is still unable to achieve precise control of individual metal wall temperature over-temperature points. Research on equipment renovation can not adapt to the high temperature and flue gas erosion of the horizontal flue for a long time by retrofitting the equipment and installing a telescopic flue gas purging system. Abrasive environment

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