Coal water slurry flame-free oxygen-enriched combustion system

Abstract

The invention discloses a coal water slurry flame-free oxygen-enriched combustion system. The system comprises a hearth, a high-speed atomization combustor, a slurry supply system, an oxygen supply system, a flue gas circulating system and a flue gas discharging and recycling system. The high-speed atomization combustor comprises a primary air nozzle, a secondary air nozzle and a coal water slurry atomization nozzle; the slurry supply system comprises a slurry storage tank, a slurry conveying pump, a stirring filter and a slurry supply pump; the oxygen supply system comprises an oxygen tank, a gas heater and a gas pressurizing pump; the flue gas circulating system comprises a flue gas heat exchanger, a dust remover, a circulating draught fan and a condenser; and the flue gas discharging and recycling system comprises a CO2 compression and storage device and a chimney. According to a coal water slurry flame-free oxygen-enriched combustion technology provided by the invention, oxygen is pressurized and heated and is mixed with circulating flue gas, and mixed gas is sprayed into a furnace to form volume combustion; coal water slurry is subjected to heat exchange through the flue gas heat exchanger, so that the initial temperature is improved and ignition heat is reduced; and the problems of a current coal water slurry boiler that the combustion efficiency is relatively low, the emission of NOx is high and the capturing cost of CO2 is high and the like can be solved.

Description

technical field [0001] The invention belongs to the technical field of coal-water slurry combustion, and more specifically relates to a flameless oxygen-enriched combustion system for coal-water slurry. Background technique [0002] Coal water slurry is a fuel composed of 60-70% coal powder, 30-40% water and a small amount of chemical additives. Compared with solid coal, coal-water slurry not only maintains the original physical characteristics of coal, but also has the same fluidity and stability as liquid fuel. Combustion of coal water slurry produces a large amount of greenhouse gas CO 2 And higher concentration of nitrogen oxides NOx, which brings great environmental problems, so the development of CO 2 The coal water slurry combustion technology with capture and low NOx emission functions is very necessary. [0003] Flameless oxygen-enriched combustion is a rapidly developing and promising combustion technology. The combustion uses pure oxygen mixed with part of the ...

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Problems solved by technology

[0005] In view of the above problems or improvement needs of the prior art, the present invention provides a flameless oxygen-enriched combustion system for coal-water slurry, which increases the initial temperature and reduces the heat of ignition by exchanging heat between the coal-water slurry and high-temperature flue gas; The entrainment effect of the high-speed jet dilutes the oxygen to a lower concentration, forming a volumetric combustion without obvious flames in the furnace, combined with the oxygen-enriched combustion technology that mixes pure oxygen and part of the circulating flue gas instead of air for combustion, and solves the current water-coal Slurry boilers have low combustion efficiency, high NOx emissions, and CO 2 Capture high cost issues

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