Flue gas system and method for increasing inlet flue temperature of scr denitrification device

Abstract

The invention discloses a flue gas system and method for raising the smoke temperature of an inlet of a SCR denitration device and relates to the technical field of flue gas denitration. The flue gas system comprises a tail smoke channel and the denitration device. A superheater and a reheater are arranged in the tail smoke channel side by side. A superheater side flue gas baffle is arranged below the superheater. A reheater side flue gas baffle is arranged below the reheater. The denitration device communicates with an outlet of the tail smoke channel. The method comprises the step that when a boiler operates in the low-load state, the opening degree of the superheater side flue gas baffle is decreased, and the opening degree of the reheater side flue gas baffle is increased so that flue gas, flowing through the superheater side originally, in the tail smoke channel can be squeezed to the reheater side. By means of the flue gas system and method, the smoke temperature of the inlet of the SCR denitration device is effectively raised; and under the condition that a unit of the same type is not subjected to equipment transformation in any form, the unit can be put into denitration before grid connection.

Description

technical field [0001] The invention relates to the technical field of flue gas denitrification, in particular to a flue gas system and method for increasing the inlet flue temperature of an SCR denitrification device. Background technique [0002] In order to reduce environmental pollution, reducing the emission of nitrogen oxides has become one of the main tasks of power plants. Selective catalytic reduction (SCR) denitrification technology is widely used in power plants due to its high denitrification efficiency and low secondary pollution. However, the catalyst used in SCR denitrification technology is only active within a certain temperature range. Under low load conditions, the flue gas temperature at the inlet of the denitrification device may be lower than the normal operating temperature of the catalyst, resulting in the failure of the SCR denitrification system to operate and eventually causing pollution. Environmental issues such as exceeding standards. [0003] ...

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Problems solved by technology

However, the catalyst used in SCR denitrification technology is only active within a certain temperature range. Under low load conditions, the flue gas temperature at the inlet of the denitrification device may be lower than the normal operating temperature of the catalyst, resulting in the failure of the SCR denitrification system to operate and eventually causing pollution. Environmental issues such as exceeding standards

[0003] Installing the flue gas bypass baffle on the side of the economizer can solve the problem of low flue gas temperature at the inlet of the SCR denitrification device during low load periods, but installing the bypass baffle will not only increase equipment investment and operation and maintenance costs, but also increase the cost of operation and maintenance during normal operation. , the bypass baffle has been subjected to high-temperature flue gas for a long time, and the failure rate is high. Once the adjustment fails, the furnace can only be shut down.

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