Adjusting device and method for selective catalytic reduction (SCR) flue gas denitration efficiency of waste heat boiler

Abstract

The invention discloses an adjusting device and method for selective catalytic reduction (SCR) flue gas denitration efficiency of a waste heat boiler. An SCR denitration reactor is connected to the back of a high-pressure superheater of the waste heat boiler. The adjusting device comprises an aftercombustion combustion chamber, wherein a flue gas outlet of the aftercombustion combustion chamber isconnected to an inlet flue of the SCR denitration reactor. When the load of the waste heat boiler is lower than a set value, the aftercombustion combustion chamber is opened and conducts combustion,and high-temperature flue gas discharged after combustion is mixed with flue gas discharged from the high-pressure superheater and then delivered into the SCR denitration reactor. The SCR denitrationreactor is connected to the back of the high-pressure superheater of the waste heat boiler, the aftercombustion combustion chamber is additionally arranged, when a unit operates in the low load, aftercombustion is conducted, a high-temperature combustion product and flue gas of an inlet of the SCR denitration reactor are mixed, the flue gas temperature is increased, the SCR flue gas denitration efficiency is improved, the concentration of NOx in flue gas at an outlet of the waste heat boiler is reduced, and the discharging standard exceeding condition under the low load working condition is avoided.

Description

technical field [0001] The invention relates to the technical field of flue gas denitrification, in particular to a device and method for adjusting the denitrification efficiency of waste heat boiler SCR flue gas. Background technique [0002] With the continuous development of society, the efficient and clean utilization of energy is vigorously advocated, and the requirements for environmental protection are becoming stricter day by day. The NOx emission concentration standards of gas-steam combined cycle power generation units fueled by natural gas are constantly increasing, which also puts forward new requirements for NOx emission control technology. updated challenges. DLN (Dry Low NOx) dry-type low-pollution combustion technology is mostly used in domestic heavy-duty gas turbines to control the generation of NOx during the combustion process. At the same time, the supporting waste heat boiler is equipped with an SCR flue gas denitrification system to further reduce the ...

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Problems solved by technology

[0004] In view of the problem of low SCR denitrification efficiency in the prior art when working at low load, a device and method for adjusting the SCR flue gas denitrification efficiency of waste heat boilers according to the present invention are proposed in order to overcome the above problems or at least partially solve the above problems

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