W flame boiler primary air waste-steam replacement method and apparatus for

Abstract

A method for replacing the primary air exhaust air of a W flame boiler, which disconnects the primary air exhaust air pipes of the pulverized coal burners on the front and rear arches of the existing W flame boiler, and cancels the exhaust air pipes leading to the combustion chamber; For some nozzles and locations where the primary air is exhausted, 5% to 30% of the total secondary air is injected downward into the combustion chamber at an angle of 0° to 60° from the vertical and at a speed of 10 to 50m / s. . A primary air exhaust gas replacement device for a W flame boiler is inserted into a secondary air duct at the original primary air exhaust gas nozzle of a pulverized coal burner. Compared with the prior art, the present invention has the following advantages: 1) It can eliminate the irrationality of the existing W flame boiler air supply mode; 2) It can improve the stability of the pulverized coal air flow flame, increase the flame stroke, and strengthen the oxygen amount in the later stage of combustion 3) Make full use of the original combustion system structure, which is very suitable for the technical transformation of the existing W flame boiler.

Description

technical field [0001] The invention relates to a method and a device for replacing primary air exhaust gas of a W-flame boiler, belonging to the technical field of W-flame boiler combustion. Background technique [0002] my country is one of the few countries in the world rich in anthracite reserves, with proven reserves of nearly 120 billion tons. However, due to the low volatile matter content of anthracite and the high precipitation temperature of volatile matter, it is difficult to ignite the pulverized coal airflow, the combustion is unstable, and it is not easy to burn out, resulting in increased mechanical incomplete combustion during boiler operation and low boiler efficiency. In order to improve the operation safety and economy of boilers burning anthracite and other low-response coals, my country introduced the FW-W flame boiler combustion technology of the American FW Company in the late 1980s. At the same time, the domestic Dongfang Boiler Factory has introduce...

AI Technical Summary

Problems solved by technology

[0011] 2. The separation effect of the pulverized coal cyclone separator is not ideal

Due to the unsatisfactory separation effect of the pulverized coal cyclone separator, the fine pulverized coal particles cannot be separated and enter the furnace with the exhaust gas; the fineness and concentration of the pulverized coal particles are important factors for the ignition of the pulverized coal airflow, and the The average fineness of pulverized coal particles in the main airflow becomes coarser and the concentration decreases, which worsens the ignition and stable combustion conditions of the main airflow

[0012] 3. One air jet is not enough

The lack of gas wind increases, the velocity of the main air flow of the primary air decreases, the rigidity of the air flow decreases, and the penetration depth and stroke of the main air flow are not long enough, resulting in insufficient amount of the main air flow to absorb the radiant heat of the furnace and to entrain the high-temperature hot flue gas, resulting in coal dust Poor Airflow Ignition Performance

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