Oxygen-enriched combustion boiler system for multistage drying of lignite

Abstract

The invention relates to an oxygen-enriched combustion boiler system for multistage drying of lignite. The oxygen-enriched combustion boiler system comprises a front dryer, a drying pipe, a coal mill,a pulverized coal distributor, a boiler, a gas preheater and a desulfurization and dehydration device which are sequentially connected in series. Compared with the prior art, according to the oxygen-enriched combustion boiler system, under the condition that normal, safe and continuous operation of the system is guaranteed, the recycling smoke is fully utilized for pre-drying lignite, and part ofwater in fuel is discharged out of the system before combustion, so that the fuel combustion efficiency is improved, the boiler smoke exhaust heat loss is reduced, the boiler heating area is remarkably reduced, the steel consumption and the manufacturing cost of the boiler are reduced, and thus the whole system has higher technical economy. In the system, the concentration of CO2 in the discharged smoke can be greatly improved by applying the oxygen-enriched combustion technology, and the recovery cost and difficulty of CO2 are greatly simplified.

Description

technical field [0001] The invention relates to an oxygen-enriched combustion boiler system, in particular to a multi-stage dry oxygen-enriched combustion boiler system. Background technique [0002] CO in coal-based electricity production 2 Emissions of CO from all human activities 2 About 25% of total emissions are CO 2 Largest single point source of emissions. CO in the exhaust gas of air-supported combustion of conventional pulverized coal boiler 2 The concentration is only 13% to 15%, which gives CO 2 The separation and capture of these materials bring great technical and economical problems. Oxygen-enriched combustion technology, also known as O 2 / CO 2 Combustion technology for organizing pulverized coal in O 2 and CO 2 Combustion in the mixed gas can greatly improve the CO in exhaust smoke 2 concentration (CO after dehydration 2 The concentration can reach more than 95%), which greatly simplifies the CO 2 recovery cost and difficulty. N 2 The content is...

AI Technical Summary

Problems solved by technology

If the temperature of the gas-solid mixture transporting powdered fuel is too low, the moisture in the flue gas will easily condense, which will cause pipeline blockage; if the temperature of the gas-solid mixture is too high, it will easily cause the powdered lignite to deflagrate and cause danger

If the oxygen concentration in the gas-solid mixture is too high, the risk of fuel spontaneous combustion and explosion will also occur; if the oxygen concentration in the gas-solid mixture is too low, it is not conducive to the ignition of coal powder

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