Method for combustion adjustment of W-type flame furnace with under-arch secondary air at adjustable down-dip angle

Abstract

The invention discloses a method for combustion adjustment of a W-type flame furnace with under-arch secondary air at an adjustable down-dip angle. The method comprises the steps that when a boiler is normally operated, the angle of an under-arch secondary air adjusting blade is adjusted, so that the air direction of the under-arch secondary air entering a lower furnace hearth is kept in a down-dip state, and the down-dip angle of the under-arch secondary air adjusting blade ranges from 1 degree to 60 degrees; the opening degree of an air door of the under-arch secondary air ranges from 10% to 70% and when the adjusting blade and the air door are adjusted, the adjustment principle that the opening degree in the middle of the furnace hearth is large and the opening degree of the two sides of the furnace hearth is small is adopted; above-arch secondary air is injected into the furnace hearth at the same time, the opening degree of an air door of the above-arch secondary air is adjusted to the range between 0 and 100%, and the adjusting principle that the opening degree of the middle of the furnace hearth is large and the opening degree of the two sides of the furnace hearth is small is adopted. According to the method, the angle of the adjusting blade 9 is adjusted, the under-arch secondary air is kept in a thorough and appropriate down-dip state, and efficient high-temperature smoke backflow is formed in the lower furnace hearth 2, so that the boiler combustion stability is remarkably improved and a high oxygen level needed for thorough-combustion of coal powder is kept.

Description

technical field [0001] The invention relates to a method for adjusting the downward inclination angle of the secondary air under the arch of a W flame boiler and the opening of the main secondary air baffle. Background technique [0002] The existing Dongfang Boiler Factory introduced the W-type flame boiler produced by Foster Wheeler Company of the United States. It is mainly used to burn low-volatile coal. In the actual use and adjustment process, it is difficult to add air when the load is high, and the combustion is stable. and poor burnout performance. The combustion chamber of this boiler is divided into an upper furnace 1 and a lower furnace 2. The front and rear walls between the upper furnace 1 and the lower furnace 2 are furnace arches. Double cyclone separated pulverized coal burners (generally 24 burners for 300MW level boilers, 12 for each front and rear arch), and each burner is equipped with an oil igniter. After the pulverized coal flow passes through the c...

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Problems solved by technology

[0004] In order to solve the problems of poor combustion stability and high carbon content in fly ash existing in the actual operation of the existing W-shaped flame boiler produced according to the technology of Foster Wheeler Company of the United States, the invention patent "A kind of adjustable W-shaped flame furnace arch The device for the direction of the secondary wind under the arch" (Patent No.: ZL 2008 1 0303381.5) adjusts the downward inclination angle of the secondary air under the arch by setting the secondary air under the arch secondary air box (9) to adjust the downward inclination adjustment blade (9)

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