Combustion method and combustion device for desulfuration and denitration of circulating fluid bed

Abstract

The invention discloses a combustion method and a combustion device for desulfuration and denitration of a circulating fluid bed. The combustion method comprises the following steps: a fuel, a desulfurizing agent, and combustion air with the quantity being higher than theoretical combustion air quantity and lower than routine combustion air quantity are supplied to a lower area of a hearth of the circulating fluid bed; a gas and solid mixture generated by combustion in the hearth of the circulating fluid bed enters a cyclone separator from the upper part of the hearth, particles in the gas and solid mixture are separated and sent back to the hearth of the circulating fluid bed, smoke in the gas and solid mixture flows into a tail flue via a center barrel at the top of the cyclone separator and then via an exit flue; complementary combustion air nozzles are formed in the part of the hearth, at the height where a fluidizing velocity is 2.5-4 times that of an air distribution plate, of the circulating fluid bed, and formed in the upper part of the hearth, and / or in an inlet section of the cyclone separator, and complementary combustion air is supplied to the complementary combustion air nozzles. The combustion device has the characteristics of system simplicity, low project investment cost, small floor area, and the like.

Description

technical field [0001] The invention relates to a combustion method and device for a circulating fluidized bed boiler, in particular to a combustion method and device for combined desulfurization and denitrification in a circulating fluidized bed boiler. Background technique [0002] Sulfur dioxide and nitrogen oxides (NOx) are important air pollutants and important substances that cause acid rain and photochemical pollution. When sulfur dioxide enters the atmosphere and reaches a certain concentration, it will cause harm to humans, animals and plants; more importantly, when the relative humidity is high and there are particulate matter, it will undergo a catalytic oxidation reaction to generate SO 3 And sulfuric acid mist, which is 10 times more toxic than sulfur dioxide. The total amount of nitrogen oxide emissions from coal-fired boilers is less than that of sulfur dioxide, but its potential harm to the environment is more serious than that of sulfur dioxide. Among them,...

AI Technical Summary

Problems solved by technology

Although this method can effectively reduce the emission of nitrogen oxides, it still cannot meet the needs of removing sulfur compounds in flue gas at the same time.

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