Decoupling combustion furnace and decoupling combustion method

Abstract

The invention provides a decoupling combustion method, which comprises the following steps: a) firstly, performing pyrolysis and gasification of fuels to generate semicoke and gas; b) secondly, combusting part of gas and semicoke to perform oxidation reaction and reduction reaction to generate coke, and applying the generated heat to the pyrolysis and gasification in step a); c) thirdly, combusting the coke and the left gas generated in step a) under the condition that an excess air coefficient is less than 1, and simultaneously generating smoke in the combustion; and d) finally, performing full secondary combustion of the smoke and the remained gas after the steps. The decoupling combustion method can increase the decoupling combustion space and intensity with a smaller floor area; the increase of the gasification zone and the gasification intensity greatly improve the load increasing capability of a decoupling combustion furnace; and in addition, because the high-temperature smoke strongly heats the fuels in the upper part of a pyrolysis and gasification chamber and has higher pyrolysis and gasification intensity, the gas output is increased and the combustion amount of solid semicoke is reduced.

Description

technical field [0001] The invention belongs to the field of raw coal combustion equipment, and in particular relates to a pyrolysis gasification decoupling combustion furnace with low nitrogen oxide emission and a decoupling combustion method. Background technique [0002] In the practical application of fuel combustion, fly ash combustibles and CO are more likely to burn out quickly and fully with the increase of combustion temperature and excess air coefficient, but on the contrary they are not easy to burn out. At the same time, the lower the combustion temperature and excess air coefficient are, the more favorable it is for denitrification and sulfur fixation. The increase of combustion temperature and excess air coefficient will make the NO produced in the combustion process x It is greatly improved, and at the same time, the reverse reaction of the sulfur-fixing reaction is increased and the sulfur-fixing agent is "frozen", which is not conducive to sulfur-fixing. Th...

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Problems solved by technology

However, in the above-mentioned patents, due to the decoupled combustion process, the pyrolysis gas of coal mainly relies on the lower semi-coke combustion to provide heat, and the air flow does not pass through the upper coal seam space, so the pyrolysis speed of coal is relatively slow, and due to the one-way The grate can only ensure that the pyrolysis gasification gas and semi-coke are transported in one direction, so decoupling combustion can only occur on one side, and the space of the pyrolysis gasification chamber cannot be fully utilized to increase the speed of pyrolysis gasification, so only It is suitable for small decoupling combustion furnaces below 1 ton / h, and it is difficult to realize large-scale decoupling combustion furnaces (greater than 1 ton / h)

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