W-shaped flame boiler grading combustion method

Abstract

The invention relates to a W-shaped flame boiler grading combustion method. Free-burning coal reacts with oxygen to form first grade combustion; the free-burning coal is formed by bituminous coal or a mixture between the bituminous coal and meager coal; and high-temperature flue gas atmosphere formed in the first stage ignites anthracite wrapped up with the high-temperature flue gas and second grade combustion is formed. A method for determining an optimal mixture ratio of a mixture ratio of the bituminous coal and the anthracite and a mixture ratio of the bituminous coal, the meager coal and the anthracite comprises steps of pre-deciding a boiler combustion strategy according to coal quality elements and an industrial analysis result, and comparing and analyzing boiler work conditions when different combustion strategies are employed to achieve an optimal boiler grading combustion coal type ratio, and an coal mill coal powder injection way. A combustion coal and the anthracite mixture ratio is determined during the boiler grading combustion process, so second combustion burn-off rate can be effectively improved; and secondary flying ash and large slag carbon content can be reduced.

Description

technical field [0001] The invention relates to a staged combustion method for a W-shaped flame boiler. Background technique [0002] The main problems of W-type flame boilers: [0003] (1) Improper air distribution causes the center of the flame to move up, even forming a double U-shaped flame, and the flame stroke of some boilers becomes shorter, which is not conducive to the combustion of anthracite, the carbon content of fly ash and large slag increase significantly, and the furnace efficiency decreases . [0004] (2) When the organization of the aerodynamic field is unreasonable, it is easy to cause the flame to float upward and directly enter the burnout chamber, causing problems such as overheating of the superheater and reheater, rising exhaust gas temperature, and slagging at the throat. [0005] (3) Since the temperature in the furnace is higher than 1500°C (the temperature at which thermal NOx is generated), the amount of NOx generated is relatively large, which...

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Problems solved by technology

[0003] (1) Improper air distribution causes the center of the flame to move up, even forming a double U-shaped flame, and the flame stroke of some boilers becomes shorter, which is not conducive to the combustion of anthracite, the carbon content of fly ash and large slag increase significantly, and the furnace efficiency decreases

[0004] (2) When the organization of the aerodynamic field is unreasonable, it is easy to cause the flame to float upward and directly enter the burnout chamber, causing problems such as overheating of the superheater and reheater, rise in exhaust gas temperature, and slagging at the throat

[0008] (6) The aerodynamic field is relatively complex. If the momentum under the arch is too large, it will easily cause the flame to shoot down the cold ash bucket and cause slagging. If the momentum above the arch is too small, it will cause the flame to lick the throat.

[0009] (7) The boiler structure is relatively complex, the design and installation of the furnace arch is difficult, the layout of the burner air powder pipeline is difficult, the steel consumption is large, the cost is high, and rich operating experience and high operating level are required, and the operation and management costs

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