Oxygen-enriched combustion boiler system for circulating fluidized bed

Abstract

An oxygen-enriched combustion boiler system for a circulating fluidized bed comprises a hearth, a cyclone separator, an externally-arranged combustion chamber, a tail smoke flue and an air supply unit. An outlet of the hearth is connected to the cyclone separator and used for outputting smoke gas containing circulating materials from the hearth; after the smoke gas containing the circulating materials is separated by the cyclone separator, the circulating materials enter the externally-arranged combustion chamber from an outlet of the lower portion of the cyclone separator, and the smoke gas portion enters the tail smoke flue from an outlet of the upper portion of the cyclone separator; and the circulating materials are input into the externally-arranged combustion chamber by the cyclone separator, fluidizing air is input into the externally-arranged combustion chamber by the air supply unit, and an outlet of the externally-arranged combustion chamber is connected to the inlet end of the hearth. According to the oxygen-enriched combustion boiler system for the circulating fluidized bed, the mode that burning is conducted on the inlet under the high oxygen concentration is adopted, the sizes of a boiler body and an auxiliary machine are greatly reduced, initial investment and operating cost of a boiler can be reduced, and the occupied area of a boiler island is reduced.

Description

technical field [0001] The invention relates to combustion equipment, in particular to a circulating fluidized bed oxygen-enriched combustion boiler system. Background technique [0002] The greenhouse gas CO produced by the burning of fossil fuels 2 It has had a serious impact on the global climate and environment. The power station industry occupies an important position in the use of fossil fuels, and is dominated by coal-fired power stations, accounting for more than 40% of the power station industry. Therefore, it is necessary to find a CO suitable for coal-fired power plants 2 Capture technical solutions. in the existing CO 2 Among capture technologies, oxyfuel combustion technology (also known as O 2 / CO 2 Flue gas recirculation combustion technology) is a large-scale industrial application of coal-fired CO 2 One of the capture technologies. This technology uses pure oxygen and circulating flue gas instead of air as the oxidant to enter the boiler for combusti...

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Problems solved by technology

However, the existing oxygen-enriched combustion technology only replaces the nitrogen in the air with a high-concentration CO 2 The volume share of oxygen in the tail flue gas varies little (21% to 27%), so compared with conventional air combustion units, the investment in the boiler body (furnace and tail heating surface) is basically unchanged, but due to the increase The investment and operating costs of the air separation oxygen generation system and flue gas recirculation system, boiler island will increase significantly, which will reduce the economic efficiency of the whole plant by about 8% to 12%, which is very important for coal-fired power stations. It is unacceptable, and it is also the main reason restricting the large-scale commercial application of existing oxyfuel combustion technology

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