Ultralow-load stable-combustion pre-pyrolysis combustion system and ultralow-load operation method

Abstract

The invention discloses an ultralow-load stable-combustion pre-pyrolysis combustion system and an ultralow-load operation method. The ultralow-load stable-combustion pre-pyrolysis combustion system comprises a coal mill, a wind box, first powder feeding pipelines, direct-current combustors, a powder feeding pipeline reversing valve, a secondary wind adjusting valve, pre-pyrolysis swirling combustors, a boiler furnace, a secondary wind pipeline and a main combustor; the central height of a spraying nozzle of each pre-pyrolysis swirling combustor is the same as the height of a spraying nozzle ofthe corresponding direct-current combustor on the same layer; the coal mill is communicated with the direct-current combustors and the pre-pyrolysis swirling combustors through the first powder feeding pipelines; the pre-pyrolysis swirling combustors are mounted on the front and rear walls of the boiler furnace; the wind box is arranged on the side wall, adjacent to the pre-pyrolysis swirling combustors, of the boiler furnace; and the wind box is communicated with the direct-current combustors and the pre-pyrolysis swirling combustors. pulverized coal can be subjected to low-temperature pyrolysis in precombustion chambers of the pre-pyrolysis swirling combustors, pyrolysis products are mixed with external secondary wind and then a mixture is sprayed into the boiler furnace to be stably burnt, so as to ensure stable operation of a boiler under the ultralow load and meet the deep peak regulation requirement.

Description

technical field [0001] The invention belongs to the field of boiler combustion, and in particular relates to an ultra-low-load stable combustion pre-pyrolysis combustion system and an ultra-low-load operation method. Background technique [0002] With the deterioration of the ecological environment, the pace of global carbon dioxide emission reduction is accelerating, and the energy structure will change. In recent years, low-carbon new energy represented by wind energy and solar energy has developed rapidly, and large-scale wind and solar energy have been connected to the grid. However, these power sources have strong randomness, energy production is intermittent, and cannot be adjusted according to the needs of the grid. characteristics, which pose a great challenge to the security and stability of the power grid. According to analysis, after the proportion of wind power and photovoltaics in the power system reaches a certain percentage of 15%-20%, every percentage point ...

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Problems solved by technology

[0007] In order to solve the problems existing in the prior art, the present invention provides an ultra-low-load stable combustion pre-pyrolysis combustion system and an ultra-low-load operation method. By installing pre-pyrolysis swirl burners on the front and rear walls of the boiler furnace, Solve the problem that the pulverized coal is ignited in the pre-combustion chamber of the swirl burner, resulting in high nitrogen oxide emissions and easy slagging, and the problem that the once-through burner cannot operate stably under ultra-low load

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