Multi-injection staged W flame boiler using swirl pulverized coal burner

Abstract

The invention discloses a multi-injection staged W flame boiler using a swirl pulverized coal burner, relates to a boiler and belongs to the technical field of W flame boiler combustion. In order to further lower the NOx emission and fly ash combustible matter content of the W flame boiler using the swirl pulverized coal burner, the W flame boiler uses the swirl pulverized coal burner with secondary air being offset completely. Secondary air pipes skew towards the side far away from the center of a hearth relative to a primary air pipe, and finally the internal secondary air pipe and the external secondary air pipe make contact with the pipe wall of the primary air pipe so that the secondary air can be offset completely; internal secondary air and external secondary air which are far away from the center of the hearth are injected step by step and carry dense pulverized coal airflow to be injected downwards, and primary and secondary staged combustion is achieved; and exhaust gas, staged air and over fire air nozzles are all arranged in a descending mode, and accordingly third, fourth, fifth and sixth staged combustion is realized. According to the W flame boiler using the swirl pulverized coal burner, multi-injection staged combustion is achieved.

Description

technical field [0001] The invention relates to a boiler, in particular to a multi-injection graded W flame boiler using a swirl pulverized coal burner. Background technique [0002] The W-flame boiler of the swirl burner in the prior art is a boiler specially designed for burning anthracite and lean coal. The following problems generally exist in the actual operation of this boiler. [0003] The upwind of W-flame boilers with swirl burners accounts for more than 60% of the total air volume, and the pulverized coal has strong oxidation at the initial stage of combustion, and NO x Emissions are high. NO x It is toxic to animals and humans, is one of the main substances that form acid rain, is also an important substance that forms photochemical smog in the atmosphere and an important factor that destroys the atmospheric ozone layer. According to the "Emission Standard of Air Pollutants for Thermal Power Plants" GB13223-2011, W Flame Boiler NO x The maximum allowable emiss...

AI Technical Summary

Problems solved by technology

However, due to the absence of overburned air, NO x Emissions are still as high as 1000mg / m 3 , and the fly ash combustible content is still at a high level

The Chinese invention patent "W Flame Boiler with Swirl Pulverized Coal Burner Primary and Secondary Air Eccentric Arrangement" was published on May 4, 2016, the application number was 201511007686.8, and the application date was December 28, 2015. The W flame was proposed The method of eccentric arrangement of the primary and secondary air pipes of the swirl burner of the boiler can reduce the NO to a certain extent by realizing partial offset of the secondary air x emissions and fly ash combustible content, to prevent slagging of the water walls on the front and rear walls of the lower furnace, but only using the swirl burner with the partial offset of the secondary air does not solve the air volume ratio between the arch and the arch, and the air volume of the arch It still accounts for more than 60% of the total air volume, and the low NO of the burner cannot be fully displayed x characteristics, NO in actual operation x Emissions up to 950mg / m 3 , fly ash combustible content up to 9%

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