CN219494145U

CN219494145U - Device for adjusting temperature of flue gas at inlet of SCR (selective catalytic reduction) reactor

Info

Publication number: CN219494145U
Application number: CN202320642036.4U
Authority: CN
Inventors: 孟晓敏; 李平; 龚立立
Original assignee: Baotou Iron and Steel Group Co Ltd
Current assignee: Baotou Iron and Steel Group Co Ltd
Priority date: 2023-03-28
Filing date: 2023-03-28
Publication date: 2023-08-08
Anticipated expiration: 2033-03-28

Abstract

The utility model discloses a device for adjusting the temperature of flue gas at an inlet of an SCR (selective catalytic reduction) reactor, which comprises a steam drum, wherein a water cooling wall is arranged below the steam drum, a primary superheater is arranged on the right side of the water cooling wall, a secondary superheater is arranged on the right side of the primary superheater, a high-temperature coal economizer is arranged below the right side of the secondary superheater, and a flue gas short-circuit pipeline is arranged on the right side of the high-temperature coal economizer. The device for adjusting the inlet flue gas temperature of the SCR reactor monitors the temperature inside the inlet of the SCR reactor through the temperature sensor, when the inlet flue gas temperature of the SCR reactor is lower than 320 ℃, the flue gas adjusting valve is opened, the inlet flue gas temperature of the SCR reactor is improved to be favorable for improving the reaction efficiency of the catalyst, the consumption of the denitration absorbent is reduced, the consumption of the flue gas nitrogen oxides is ensured to be within a specified discharge range, and the device for adjusting the inlet flue gas temperature of the SCR reactor has the advantages of simple structure, reliable work, convenience in manufacturing and installation, and convenience in operation.

Description

Device for adjusting temperature of flue gas at inlet of SCR (selective catalytic reduction) reactor

Technical Field

The utility model relates to the technical field of gas boilers, in particular to a device for adjusting the temperature of flue gas at an inlet of an SCR (selective catalytic reduction) reactor.

Background

The gas boiler is a special furnace type of iron and steel enterprises, is mainly used for consuming blast furnace gas and converter gas generated in the steelmaking and ironmaking processes, can comprehensively utilize energy sources of the iron and steel enterprises, can create benefits for the enterprises, and needs denitration, desulfurization and dust removal transformation; the denitration process mainly comprises low-nitrogen combustion, an SNCR method, an SCR method and the like, wherein the SCR method (selective catalytic reduction method) is mature in process, relatively moderate in price and wide in adaptability to smoke components, the SCR method is divided into a high-temperature SCR method, a medium-low temperature SCR method and an ultralow-temperature SCR method, the high-temperature SCR method is high in reaction activity and relatively low in price, most of the boilers currently adopt the high-temperature SCR method, the optimal reaction temperature of the high-temperature SCR method is about 360 ℃, and when the smoke temperature is lower than 320 ℃ or higher than 400 ℃, the catalyst activity is greatly reduced.

The existing gas boiler is influenced by the condition of the blast furnace and the intermittent production of the converter, so that the fluctuation of the temperature of flue gas at the inlet of the SCR reactor of the boiler is larger, the fluctuation range is about 100 ℃, and when the temperature of the flue gas is not in the optimal reaction temperature range of SCR, the consumption of a denitration absorbent is increased.

Disclosure of Invention

The utility model aims to provide a device for adjusting the temperature of flue gas at an inlet of an SCR reactor, which aims to solve the problems that in the prior art, the flue gas at the inlet of the SCR reactor of a boiler fluctuates greatly due to the influence of the condition of a blast furnace and the intermittent production of a converter, the fluctuation range is about 100 ℃, and the consumption of a denitration absorbent is increased when the temperature of the flue gas is not in the optimal reaction temperature range of SCR.

In order to achieve the above purpose, the present utility model provides the following technical solutions: the utility model provides a device for adjusting SCR reactor entry flue gas temperature, includes the steam drum, the water-cooling wall is installed to the below of steam drum, the one-level superheater is installed on the right side of water-cooling wall, the second grade superheater is installed on the right side of one-level superheater, high temperature economizer is installed to the right side below of second grade superheater, flue gas short circuit pipeline is installed on the right side of high temperature economizer, flue gas short circuit pipeline's internally mounted has the flue gas governing valve, the expansion joint is installed to the top of flue gas governing valve, the below of high temperature economizer is provided with the SCR reactor entry, the internally mounted of SCR reactor entry has temperature sensor.

Preferably, the flue gas short-circuit pipeline is communicated with the inlet of the high-temperature economizer, and the flue gas short-circuit pipeline is communicated with the inlet of the SCR reactor.

Preferably, the flue gas short circuit pipeline is made of Cr20 high heat resistant steel material.

Preferably, the flue gas short circuit pipeline is further provided with:

and the heat insulation layer is arranged on the outer surface of the flue gas short circuit pipeline.

Preferably, the flue gas regulating valve adopts an electric regulating valve, and the flue gas regulating valve can resist the high temperature of 650 ℃.

Preferably, the SCR reactor inlet is further provided with:

the high-temperature preheater is arranged below the inlet of the SCR reactor, the low-temperature economizer is arranged below the high-temperature preheater, the low-temperature preheater is arranged below the low-temperature economizer, and the blower outlet is arranged on the right side of the low-temperature preheater.

Compared with the prior art, the utility model provides a device for adjusting the temperature of the flue gas at the inlet of an SCR reactor, which has the following beneficial effects: this adjust SCR reactor entry flue gas temperature's device monitors the inside temperature of SCR reactor entry through temperature sensor, and when SCR reactor entry flue gas temperature was less than 320 ℃, open the flue gas governing valve, improve SCR reactor entry flue gas temperature and be favorable to improving catalyst reaction efficiency, reduce denitration absorbent consumption, guarantee that flue gas nitrogen oxide is within the specified emission scope to this adjust SCR reactor entry flue gas temperature's device simple structure, reliable operation, convenient manufacturing, quick, the convenient operation of installation.

Drawings

FIG. 1 is a schematic diagram of the overall structure of the present utility model;

fig. 2 is a schematic diagram of the external structure of the flue gas short circuit pipeline according to the present utility model.

In the figure: 1. a steam drum; 2. a water cooling wall; 3. a primary superheater; 4. a secondary superheater; 5. a high temperature economizer; 6. an expansion joint; 7. a flue gas regulating valve; 8. a flue gas short circuit pipeline; 9. a high temperature preheater; 10. a low-temperature economizer; 11. a low temperature preheater; 12. an outlet of the blower; 13. a temperature sensor; 14. an SCR reactor inlet; 15. and a heat preservation layer.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

Referring to fig. 1 and 2, a device for adjusting the temperature of flue gas at an inlet of an SCR reactor comprises a steam drum 1, a water cooling wall 2 is installed below the steam drum 1, a primary superheater 3 is installed on the right side of the water cooling wall 2, a secondary superheater 4 is installed on the right side of the primary superheater 3, a high-temperature economizer 5 is installed below the right side of the secondary superheater 4, and a flue gas short-circuit pipeline 8 is installed on the right side of the high-temperature economizer 5; the flue gas short-circuit pipeline 8 is made of Cr20 high heat-resistant steel material, and a flue gas regulating valve 7 is arranged in the flue gas short-circuit pipeline 8; the flue gas regulating valve 7 adopts an electric regulating valve, the flue gas regulating valve 7 can resist 650 ℃ high temperature, the expansion joint 6 is arranged above the flue gas regulating valve 7, and the SCR reactor inlet 14 is arranged below the high-temperature economizer 5; the flue gas short-circuit pipeline 8 is communicated with the inlet of the high-temperature economizer 5, the flue gas short-circuit pipeline 8 is communicated with the inlet 14 of the SCR reactor, and a temperature sensor 13 is arranged in the inlet 14 of the SCR reactor; a heat insulating layer 15 mounted on the outer surface of the flue gas short circuit pipe 8; according to the device for adjusting the flue gas temperature at the inlet of the SCR reactor, the temperature inside the inlet 14 of the SCR reactor is monitored through the temperature sensor 13, when the flue gas temperature at the inlet 14 of the SCR reactor is lower than 320 ℃, the flue gas adjusting valve 7 is opened, the flue gas temperature at the inlet 14 of the SCR reactor is improved, the catalyst reaction efficiency is improved, the consumption of a denitration absorbent is reduced, the consumption of flue gas nitrogen oxides is ensured to be within a specified emission range, and the device for adjusting the flue gas temperature at the inlet of the SCR reactor is simple in structure, reliable in operation, convenient to manufacture, quick to install and convenient to operate; a high temperature preheater 9 which is arranged below the SCR reactor inlet 14, a low temperature economizer 10 is arranged below the high temperature preheater 9, a low temperature preheater 11 is arranged below the low temperature economizer 10, and a blower outlet 12 is arranged on the right side of the low temperature preheater 11.

Working principle: when the device for adjusting the flue gas temperature at the inlet of the SCR reactor is used, firstly, high-temperature flue gas is generated after blast furnace gas and converter gas are combusted in a boiler combustion chamber, water cooling walls 2 are arranged around the combustion chamber, and after a primary superheater 3 and a secondary superheater 4 arranged in a horizontal flue absorb part of flue gas heat, the flue gas temperature at the inlet of a high-temperature economizer 5 is about 500-600 ℃; under normal conditions, the flue gas gradually flows through the high-temperature economizer 5, the SCR reactor, the high-temperature preheater 9, the low-temperature economizer 10 and the low-temperature preheater 11 and then is discharged from the blower outlet 12. When the gas amount of the boiler suddenly decreases and the temperature of the inlet 14 of the SCR reactor suddenly decreases to below 320 ℃, the temperature sensor 13 monitors the temperature decrease in the inlet 14 of the SCR reactor and feeds information back to the processing center, the processing center sends a command to the controller, the flue gas adjusting valve 7 is controlled to open to introduce high-temperature flue gas at the inlet of the high-temperature economizer 5 into the SCR reactor through the flue gas short-circuit pipeline 8, the purpose of adjusting the temperature of the inlet 14 of the SCR reactor is achieved, and the expansion joint 6 is used for absorbing the expansion amount generated after the pipeline is heated or after the pipeline is cooled, which is the working principle of the device for adjusting the temperature of the flue gas at the inlet of the SCR reactor.

Although embodiments of the present utility model have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the utility model, the scope of which is defined in the appended claims and their equivalents.

Claims

1. An apparatus for regulating the temperature of flue gas at an inlet of an SCR reactor, comprising:

the steam drum (1), water-cooled wall (2) is installed to the below of steam drum (1), one-level superheater (3) is installed on the right side of water-cooled wall (2), secondary superheater (4) are installed on the right side of one-level superheater (3), high-temperature economizer (5) are installed to the right side below of secondary superheater (4), flue gas short circuit pipeline (8) are installed on the right side of high-temperature economizer (5), internally mounted of flue gas short circuit pipeline (8) has flue gas governing valve (7), expansion joint (6) are installed to the top of flue gas governing valve (7), the below of high-temperature economizer (5) is provided with SCR reactor entry (14), the internally mounted of SCR reactor entry (14) has temperature sensor (13).

2. A device for regulating the temperature of flue gas at the inlet of an SCR reactor according to claim 1, characterized in that the flue gas short-circuit duct (8) is in communication with the inlet of the high temperature economizer (5) and the flue gas short-circuit duct (8) is in communication with the inlet (14) of the SCR reactor.

3. A device for regulating the temperature of flue gas at the inlet of an SCR reactor according to claim 1, characterized in that the flue gas short circuit pipe (8) is made of Cr20 high heat resistant steel material.

4. A device for regulating the temperature of the flue gas at the inlet of an SCR reactor according to claim 1, characterized in that the flue gas shorting duct (8) is also provided with:

and the heat insulation layer (15) is arranged on the outer surface of the flue gas short circuit pipeline (8).

5. A device for regulating the temperature of flue gas at the inlet of an SCR reactor according to claim 1, characterized in that the flue gas regulating valve (7) is an electric regulating valve and the flue gas regulating valve (7) is resistant to high temperatures of 650 ℃.

6. A device for regulating the temperature of flue gas at the inlet of an SCR reactor according to claim 1, characterized in that the SCR reactor inlet (14) is further provided with:

the high-temperature preheater (9) is arranged below the SCR reactor inlet (14), the low-temperature economizer (10) is arranged below the high-temperature preheater (9), the low-temperature preheater (11) is arranged below the low-temperature economizer (10), and the blower outlet (12) is arranged on the right side of the low-temperature preheater (11).