Method and system thereof for oxygen-enriched flameless combustion of coal powder

Abstract

The invention discloses a method and a system thereof for oxygen-enriched flameless combustion of coal powder. By adopting the method, the stability, burn-off rate and radiative heat transfer of combustion can be improved through flameless combustion on the basis of enriching CO2 during oxygen-enriched combustion. High-temperature flue gas generated by the oxygen-enriched combustion is injected into a hearth in the form of high-speed jet flow through a direct-current flameless burner, and quick and uniform mixing of heat and quality in the hearth can be realized through high-speed jet flow entrainment. The system comprises an oxygen injection system, and a primary air oxygen-injection point is positioned between a circulating fan and a flow regulating valve; a secondary air oxygen-injection point is positioned between a booster fan and a hearth outlet; a primary air pipe of the direct-current flameless burner is positioned in the center, and a secondary air pipe is parallel to the primary air pipe and is circularly arranged around the primary air pipe; the booster fan with a high-pressure head is arranged on a secondary air duct, and secondary air is boosted and speeded up and then enters the hearth in the form of the high-speed jet flow. The heat utilization ratio of the method and the system can be improved by 10-25%, and the generation of NOX can be reduced by 15-40%.

Description

technical field [0001] The invention relates to the combustion technology of a coal-fired boiler, in particular to a coal powder oxygen-enriched flameless combustion method and a system thereof. The present invention realizes CO 2 While reducing emissions, it can significantly reduce NO X Generate, improve combustion stability and heat utilization efficiency. Background technique [0002] Oxygen-enriched combustion is a circulating combustion technology that mixes circulating flue gas with pure oxygen into the furnace for combustion, so that CO 2 Continuous enrichment (greater than 80%) to facilitate capture and storage to achieve CO 2 purpose of emission reduction. In the process of oxygen-enriched combustion, due to the air leakage of the system and the circulation of nitrogen-containing flue gas, the nitrogen element in the flue gas is continuously accumulated, which makes the NO in the flue gas X Emission concentration increases; at the same time, affected by CO 2 ...

AI Technical Summary

Problems solved by technology

Traditionally, flameless combustion technology needs to be realized by preheating air at high temperature (usually higher than 1000°C), and the corresponding facilities and operating procedures are relatively complicated, making it difficult to apply to solid fuels including pulverized coal

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