Circulating fluidized bed boiler reducing atmosphere combustion technology

Abstract

The invention discloses a circulating fluidized bed boiler reducing atmosphere combustion technology. In the circulating fluidized bed boiler reducing atmosphere combustion technology, a circulating fluidized bed boiler is used; a primary air chamber of the circulating fluidized bed boiler is connected with a primary air pipeline; a combustion chamber of the circulating fluidized bed boiler is connected with a secondary air pipeline; a smoke discharging pipeline of the circulating fluidized bed boiler is provided with a smoke recirculating pipe; the smoke recirculating pipe is connected with the primary air chamber of the circulating fluidized bed boiler; and the primary air pipeline, the secondary air pipeline and the smoke recirculating pipe are provided with a flow control valve and a gas flow sensor respectively. The circulating fluidized bed boiler reducing atmosphere combustion technology has the advantages that the proportion of primary air, the proportion of secondary air and the recirculating quantity of smoke are controlled accurately, the excess air coefficient alpha in a primary air combustion region is smaller than 1, namely, the primary air combustion region is in a fuel-rich oxygen-deficient combustion state, and the total excess air coefficient alpha in the boiler is slightly greater than 1 and is about 1.1.

Description

technical field [0001] The invention relates to a circulating fluidized bed boiler, in particular to a reducing atmosphere combustion process of a circulating fluidized bed boiler. Background technique [0002] The NO produced by circulating fluidized bed boiler under normal combustion conditions X Mainly fuel type, NO in the furnace X More than 95% of them exist in the form of NO. At present, in order to reduce NO X Flue gas recirculation technology is usually used for emission, that is, part of the flue gas discharged after boiler combustion is mixed into the primary air and passed into the furnace. Combustion temperature to reduce NO in the boiler combustion process X emissions, and in actual production, the temperature is used as the detection index to control the proportion of primary air, secondary air and flue gas recirculation of circulating fluidized bed boilers, but the actual emission of NO in production X It is often in a fluctuating state of high and low, wh...

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Problems solved by technology

[0002] The NO produced by circulating fluidized bed boiler under normal combustion conditions X Mainly fuel type, NO in the furnace X More than 95% of them exist in the form of NO. At present, in order to reduce NO X Flue gas recirculation technology is usually used for emission, that is, part of the flue gas discharged after boiler combustion is mixed into the primary air and passed into the furnace. Combustion temperature to reduce NO in the boiler combustion process X emissions, and in actual production, the temperature is used as the detection index to control the proportion of primary air, secondary air and flue gas recirculation of circulating fluidized bed boilers, but the actual emission of NO in production X It is often in a fluctuating state of high and low, which is not conducive to enterprises to accurately grasp the emission situation, and it is also not conducive to the supervision of enterprises by environmental protection departments

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