Flue gas recirculation pulverized coal boiler combustion system and its working mode switching method

Abstract

The invention discloses a smoke recycling pulverized coal boiler combustion system and a working condition switching method thereof, and belongs to the fields of adjusting and control methods of oxygen-enriched combustion of a pulverized coal boiler. The smoke recycling pulverized coal boiler combustion system and the working condition switching method thereof solve the adjusting problem of the pulverized coal boiler in the switching process from an air combustion working condition to an oxygen-enriched combustion working condition. The smoke recycling pulverized coal boiler combustion system comprises a coal feeding machine, a burner, a boiler, a denitrator, an air pre-heater, an ash handling equipment, a desulfurizer and an induced draft fan. The working condition switching method of the smoke recycling pulverized coal boiler combustion system comprises the steps of arranging detection equipment, controlling recycling valves and an inlet valve, controlling the outlet flow of an air feeder and controlling oxygen injection amount. According to the smoke recycling pulverized coal boiler combustion system and the working condition switching method thereof, the changing parameters of the working condition switching process are obtained from related detection points in the combustion system, a circulation factor is determined through recycling smoke amount, oxygen injection flow of primary wind and secondary wind is determined through the oxygen amount of the outlet of a hearth, fluctuations of the circulation smoke amount, the air flow and the oxygen injection amount are maintained in a reasonable range in the switching process, switching from the air combustion working condition to the oxygen-enriched combustion working condition is achieved safely and stably, and the concentration of CO2 in the smoke is maintained.

Description

technical field [0001] The invention belongs to an oxygen-enriched combustion adjustment and control method of a pulverized coal boiler, in particular to a flue gas recirculation pulverized coal boiler combustion system and a working mode switching method thereof, which is applicable to the switching process of a coal-fired boiler from air combustion to oxygen-enriched combustion in the control. Background technique [0002] Carbon dioxide is the main cause of global temperature rise and frequent extreme weather. The resource conditions of "rich coal, little gas, and oil shortage" determine that China's energy structure will continue to use coal as the main energy source for a long time to come. In 2011, China CO 2 The emissions are 8241Mt, ranking first in the world, accounting for 24.6% of the world's total emissions. In view of my country's energy structure and carbon emission reduction tasks, it is urgent to find a clean coal combustion technology to reduce carbon emi...

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Problems solved by technology

Most of the above studies are in the laboratory stage, and the actual air / oxygen combustion switching operating conditions depend on the change rate of the flue gas circulation rate and the coordination of the air flow rate

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