Combustion method and device of coupled environment-friendly fluidized bed boiler

Abstract

The invention discloses a combustion method and device of a coupled environment-friendly fluidized bed boiler. The device is characterized in that a primary air chamber and a secondary air chamber are arranged at the bottom ends of a primary combustion chamber and a secondary combustion chamber respectively; the primary combustion chamber is provided with a fuel inlet, a primary non-burnout fuel circulation pipe communicated with the lower end of the secondary combustion chamber is arranged at the lower end of the primary combustion chamber, and the primary combustion chamber is provided with a primary high-temperature flue gas circulation pipe communicated with the secondary combustion chamber; the secondary combustion chamber is provided with an upper secondary air inlet, a lower secondary air inlet and a desulfurizer inlet; and the upper end of the secondary combustion chamber is communicated with a cyclone separator, a high-temperature flue gas outlet is formed in the top end of the cyclone separator, and the bottom end of the cyclone separator is communicated with the primary combustion chamber through a high-temperature circulating ash circulation pipe. By virtue of the coupled staged combustion type fluidized bed boiler, solid fuel such as fuel coal or biomass is fully combusted and high-efficiency desulfurization and denitration effects are achieved.

Description

technical field [0001] The invention relates to a combustion method and device for a coupled environment-friendly fluidized bed boiler, belonging to the technical field of boiler combustion. [0002] Background technique [0003] With the country's emphasis on environmental protection, the emission standards of flue gas pollutants from power generation boilers are becoming increasingly stringent. For circulating fluidized bed boilers, staged combustion structures are currently used to reduce NO X The generation of coal, especially for high volatile coal, the anoxic combustion in the dense phase zone at the lower part of the furnace helps coke and CO to NO X The reduction reaction, so that part of the NO X is reduced to N 2 . From the perspective of denitrification, reducing the primary air rate can achieve NO X However, due to factors such as the structure of the fluidized bed and the combustion ratio in the dense phase zone of the furnace, the change of the primary ai...

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Problems solved by technology

[0005] To sum up, most of the existing fluidized bed boilers use a single furnace structure and a combustion method with graded air distribution to reduce NO X From the perspective of denitrification, reduce the primary air rate to strengthen the reducing atmosphere in the dense phase area to reduce NO emissions X However, affected by the structure of the fluidized bed furnace, in order to ensure that the materials in the furnace are fully fluidized, the reduction of the primary air rate is severely restricted; from the perspective of desulfurization, the desulfurization reaction in the fluidized bed boiler needs to consume oxygen, but The denitrification reaction in the furnace is very sensitive to the amount of oxygen, and it is difficult to solve the contradiction between desulfurization and denitrification in the furnace

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