Airless rear-mounted w-flame boiler with secondary air nozzles on the arch and air distribution method

Abstract

A post-exhaust W-flame boiler with an arched secondary air nozzle and an air distribution method, belonging to the technical field of boilers, to solve the problem of late ignition of the pulverized coal airflow of the double-cyclone dense and light pulverized coal burner W flame boiler, poor burnout and poor burnout. Unreasonable distribution of secondary air volume above and below the arch, low level of staged combustion in the furnace, and high NOx emissions. The invention includes a furnace body, two rows of double cyclone thick and thin pulverized coal burners, and secondary air nozzles on the arch; the two exhaust gas nozzles of each double cyclone tube burner are combined into one near secondary air nozzle arranged on the corresponding arch. At the center side of the furnace, the invention also proposes a combustion adjustment method for a W flame boiler using the secondary air on the arch and the exhaust air behind it. The invention optimizes the secondary air ratio of the boiler and reduces the NOx emission level of the boiler. At the same time, the reasonable arrangement of the thick and thin pulverized coal airflow is beneficial to promote the ignition and combustion of the pulverized coal airflow and prevent the slagging of the front and rear walls of the boiler.

Description

technical field [0001] The invention relates to a coal-fired power station boiler, in particular to a spent gas rear-mounted W flame boiler with secondary air nozzles arranged on an arch and an air distribution method, belonging to the technical field of boiler combustion. Background technique [0002] The W flame boiler is a power station boiler specially designed for burning low-volatile and refractory coal. It has the advantages of high furnace temperature and long combustion stroke of pulverized coal gas flow. W-flame boilers were introduced in Western Europe and other regions. Due to the abundant reserves of anthracite and lean coal resources in China, and the low price compared with other power coals, W-flame boilers were soon widely used and became one of the main furnace types for thermal power generation. At present, there are more than 130 W-flame boilers under construction or already under construction in China, with a total installed capacity of more than 41,000M...

AI Technical Summary

Problems solved by technology

Most of the secondary air is fed into the furnace under the arch, and the pulverized coal is burned in an oxygen-rich environment, and the air classification level in the furnace is low, which is not conducive to suppressing the formation of fuel-type NOx

[0004] In summary, during the operation of FW-type W-flame boilers, there are generally problems such as high NOx emissions, late ignition of pulverized coal airflow, unstable combustion, and slagging of the front and rear walls.

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