CN112892205A - Device and method for heating SCR (selective catalytic reduction) denitration flue gas by using pulverized coal furnace - Google Patents
Device and method for heating SCR (selective catalytic reduction) denitration flue gas by using pulverized coal furnace Download PDFInfo
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
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- F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES
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- F23J15/08—Arrangements of devices for treating smoke or fumes of heaters
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Abstract
A device and a method for heating SCR denitration flue gas by a pulverized coal furnace belong to the technical field of flue gas desulfurization and denitration. The invention provides a method for heating flue gas by a pulverized coal furnace, which is characterized in that high-temperature and high-dust flue gas generated by the pulverized coal furnace is subjected to partial dust removal by a high-temperature dust removal device and then mixed into the original flue gas, so that the heating and the temperature rise of the flue gas are realized, the dust amount mixed into the original flue gas is reduced, and the risk of catalyst blockage is reduced. The mixed high-temperature flue gas and the original flue gas pass through the subsequent denitration, desulfurization and dust removal treatment devices together, and finally reach the standard to be discharged.
Description
Technical Field
The invention relates to a device and a method for heating SCR denitration flue gas by a pulverized coal furnace, and belongs to the technical field of steel sintering and pellet flue gas desulfurization and denitration.
Background
In recent years, with the stricter environmental protection requirements, the treatment of industrial flue gas becomes necessary for various industries. The SCR denitration technology is the most mature and reliable technology for denitration of the current flue gas, and becomes the first choice for denitration treatment of the industrial flue gas, but the optimal activity temperature of the mature and economic catalyst is 260-330 ℃. For industrial flue gas with temperature lower than the lowest active temperature, the process needs to heat the flue gas to raise the temperature. Because the flue gas temperature is high, the volume is big, the most efficient, reliable heating scheme is exactly to set up the heating furnace, lets the high temperature flue gas that its produced mix into former flue gas directly, reaches the purpose of rapid heating up. The fuel of the heating furnace adopts coal gas and natural gas which are the current first choice for reasons of less pollution, convenient control, convenient maintenance and the like, but when no coal gas or natural gas is available in a factory, the coal-fired heating furnace is the first scheme to be considered, but dust and SO in high-temperature flue gas generated by the coal-fired heating furnace2、NOXThe content of pollutants is high, the direct mixing of the flue gas into the original flue gas inevitably increases the content of pollutants in the original flue gas, especially dust, and the content of the dust is far lower than that of high-temperature flue gas generated by a coal-fired heating furnace because the sintering and pelletizing flue gas is treated by process electric precipitation before desulfurization and denitrification treatment. The increase of the dust content of the high-temperature flue gas directly mixed into the original flue gas inevitably increases the risk of catalyst blockage, and is very unfavorable for the stable operation of a denitration system.
Disclosure of Invention
In order to solve the technical problem, the invention provides a device and a method for heating SCR denitration flue gas by a pulverized coal furnace, which mainly comprise the following steps: the device comprises a pulverized coal furnace, a bleeding valve, a high-temperature flue gas electric valve, a high-temperature dust remover, a hot air bellow, a hot air distribution device, a combustion fan, an electric air damper, a GGH heat exchanger, a vertical flue, a static mixer and an SCR reactor.
A device for heating SCR denitration flue gas by a pulverized coal furnace comprises the pulverized coal furnace 1, a bleeding valve 2, a high-temperature flue gas electric valve 3, a high-temperature dust remover 4, a hot air bellow 5, a hot air distribution device 6, a combustion fan 7, an electric adjusting air door 8, a GGH heat exchanger raw flue gas side 9, a vertical flue 10, a static mixer 11, an SCR reactor 12, a GGH heat exchanger clean flue gas side 13 and an ammonia injection grid 14;
the pulverized coal furnace 1 is connected with a high-temperature dust collector 4 through a bleeding valve 2 and a high-temperature flue gas electric valve 3, the high-temperature dust collector 4 is connected with a hot air bellows 5, the hot air bellows 5 is connected with a vertical flue 10 through a hot air distribution device 6, the vertical flue 10 is connected with the pulverized coal furnace 1 through a combustion fan 7, an electric adjusting air door 8 is connected with a raw flue gas side 9 of a GGH heat exchanger through a flue, the raw flue gas side 9 of the GGH heat exchanger is connected with the vertical flue 10, the hot air distribution device 6 is positioned at the raw flue gas side 9 of the GGH heat exchanger, an ammonia injection grid 14 is positioned above the hot air distribution device 6, a static mixer 11 is positioned above the ammonia injection grid 14, the ammonia injection grid 14 and the static mixer 11 are both installed in the vertical flue 10, one end of an SCR reactor 12 is connected with the other end of the vertical flue 10, and the SCR reactor 12 is.
A method for heating SCR denitration flue gas by a pulverized coal furnace comprises the following steps:
firstly, after starting to introduce flue gas, raw flue gas enters a subsequent desulfurization and dust removal device after passing through an electric damper 8, a raw flue gas side 9 of a GGH heat exchanger, a vertical flue 10, a static mixer 11, an SCR reactor 12 and a clean flue gas side 13 of the GGH heat exchanger in sequence;
secondly, a flue gas pressure monitoring point is arranged at an outlet flue gas pipeline of a raw flue gas side 9 of the GGH heat exchanger, an electric damper 8 is arranged at an inlet flue gas pipeline of the raw flue gas side 9 of the GGH heat exchanger, and after the system is filled with flue gas, the pressure at the outlet flue gas pipeline of the raw flue gas side 9 of the GGH heat exchanger is controlled within a set range by adjusting the electric damper 4;
step three, starting the pulverized coal furnace 1, controlling the pressure in the hearth within a set range, allowing high-temperature flue gas generated by the pulverized coal furnace 1 to sequentially pass through a high-temperature flue, a high-temperature dust remover 4, a hot air bellow 5 and a hot air distribution device 6 by virtue of the pressure difference between the hearth and a vertical flue 10, enter the vertical flue 10, and mix with the original flue gas, and allowing the flue gas to start to heat;
step four, the system gradually heats up the flue gas by means of a flue gas heating device and a GGH heat exchanger until the temperature of the flue gas in the SCR reactor 12 reaches the designed reaction temperature, and adjusts the heat supply amount of the pulverized coal furnace 1 by adjusting the coal supply amount and the combustion-supporting air amount of the pulverized coal furnace to stabilize the temperature of the flue gas at the designed value;
fifthly, the flue gas temperature of the system is stable, after the flue gas temperature in the SCR reactor 12 reaches the design temperature, reducing agents required for reaction are provided for the flue gas through the ammonia injection grid 14, and the reducing agents are mixed with the original flue gas and then uniformly distributed through the mixing action of the static mixer 11 and a flow guide device in the flue;
after the process, the flue gas with the denitration reaction conditions enters an SCR reactor 12, the denitration reaction is completed under the action of a catalyst, the denitrated flue gas enters a clean flue gas side 13 of a GGH heat exchanger, and the denitrated flue gas enters a subsequent desulfurization and dust removal device through a flue gas pipeline after heat exchange;
seventhly, in order to respond to emergency situations, a high-temperature flue gas electric valve 3 is arranged on a high-temperature flue gas pipeline from an outlet of the pulverized coal furnace 1 to the high-temperature dust remover 4, and a diffusing pipe and a diffusing valve 2 are arranged on a high-temperature flue between the pulverized coal furnace 1 and the high-temperature flue gas electric valve 3; when the main flue gas system is abnormal, the combustion-supporting fan 7 is stopped and the high-temperature flue gas electric valve 3 is closed in an interlocking manner, and residual flue gas of the pulverized coal furnace is temporarily discharged through the diffusing pipe and the diffusing valve 2.
The pressure setting range of the outlet flue gas pipeline at the raw flue gas side 9 of the GGH heat exchanger is-1500 Pa to-2000 Pa.
The pressure in the hearth is controlled within a set range of-50 Pa to-200 Pa.
The designed reaction temperature in the SCR reactor 12 is 310-340 ℃.
The flue gas temperature of the system is stable, namely the flue gas temperature of an inlet 9 at the raw flue gas side of the GGH heat exchanger is 150-160 ℃, and the flue gas temperature of an outlet 9 at the raw flue gas side of the GGH heat exchanger is 285-305 ℃; the inlet flue gas temperature of the clean flue gas side 13 of the GGH heat exchanger is 310-330 ℃, and the outlet flue gas temperature of the clean flue gas side 13 of the GGH heat exchanger is 180-190 ℃.
High-temperature flue gas generated by the pulverized coal furnace is conveyed to the vertical flue through the high-temperature flue gas pipeline and is mixed with raw flue gas in the vertical flue, so that the temperature rise of the flue gas is realized. And a high-temperature flue gas electric valve, a high-temperature dust remover, a hot air bellow and a hot air distributing pipe are sequentially arranged on a high-temperature flue gas pipeline from the outlet of the pulverized coal furnace to the vertical flue.
The temperature of the flue gas at the outlet of the pulverized coal furnace is high, generally can reach 600-800 ℃, and the content of the dust in the flue gas can reach 3000mg/Nm3In order to relieve the adverse effect of high dust content on the catalyst after the flue gas is mixed, part of dust in the high-temperature flue gas at the outlet of the pulverized coal furnace is removed by a high-temperature dust remover and then the high-temperature flue gas is sent into a vertical flue.
The high-temperature flue gas overcomes the resistance of a high-temperature flue pipeline, a high-temperature dust remover, a hot air bellow and a hot air uniform distribution device by utilizing the pressure difference between the inside of the hearth and the vertical flue.
The combustion-supporting air of the pulverized coal furnace in the flue gas heating system adopts raw flue gas after passing through the GGH heat exchanger, and the oxygen content in the sintering and pelletizing flue gas is high and can reach 16-19 percent, so that the combustion requirement can be met. In order to save fuel consumption, the pulverized coal furnace combustion-supporting air adopts raw flue gas after heat exchange by a GGH heat exchanger.
The SCR denitration is arranged in front of the desulfurization and dust removal device, and the flue gas generated by the pulverized coal furnace contains dust and SO2Pollutants such as NOx and the like, and high-temperature flue gas are mixed into the original flue gas and then sequentially pass through the denitration device, the desulfuration device and the dust removal device together with the original flue gas, so that the requirements of ultralow emission standards are met.
The invention has the advantages that:
the flue gas heating system adopts a pulverized coal furnace, and solves the problem that the most mature and reliable SCR denitration process is difficult to adopt due to the fact that clean energy such as coal gas, natural gas and the like does not exist in a factory.
High-temperature and high-dust flue gas generated by the pulverized coal furnace is subjected to high-temperature dust removal and then is mixed with the original flue gas, so that the amount of the dust brought into a system is greatly reduced, and the risk of catalyst blockage is reduced.
The pulverized coal furnace combustion-supporting air adopts the raw flue gas after heat exchange of GGH, the temperature can reach 290-310 ℃, and the energy consumption is saved.
The emergency diffusing device is arranged, when the main flue gas system is abnormal, the high-temperature flue gas pipeline between the pulverized coal furnace and the main system is cut off in time, and residual flue gas is discharged through the diffusing device, so that the danger of positive pressure operation of the fluidized bed furnace caused by the abnormality of the main system can be avoided.
Drawings
FIG. 1 is a schematic flow chart of the system of the present invention. The system comprises a pulverized coal furnace 1, a blow-off valve 2, a high-temperature flue gas electric valve 3, a high-temperature dust remover 4, a hot air bellow 5, a hot air distribution device 6, a combustion-supporting fan 7, an electric air damper 8, a raw flue gas side of a GGH heat exchanger 9, a vertical flue 10, a static mixer 11, an SCR reactor 12, a clean flue gas side of a GGH heat exchanger 13 and an ammonia injection grid 14.
Detailed Description
In order to make the present invention more comprehensible, it is described below with reference to fig. 1.
The invention relates to a device for heating SCR denitration flue gas by a pulverized coal furnace, which comprises: the device comprises a pulverized coal furnace 1, a diffusion valve 2, a high-temperature flue gas electric valve 3, a high-temperature dust remover 4, a hot air bellow 5, a hot air distribution device 6, a combustion fan 7, an electric air damper 8, a GGH heat exchanger raw flue gas side 9, a vertical flue 10, a static mixer 11, an SCR reactor 12, a GGH heat exchanger clean flue gas side 13 and an ammonia injection grid 14.
The high-temperature flue gas generated by the pulverized coal furnace 1 enters the high-temperature dust collector 4 through the high-temperature flue, enters the hot air bellows 5 through the high-temperature flue after dust removal, and finally enters the vertical flue 10 through the hot air distribution device 6 to be mixed with the raw flue gas from the raw flue gas side 9 of the GGH heat exchanger, so that the heating of the flue gas is realized. The high-temperature flue gas generated by the pulverized coal furnace 1 overcomes all resistance of the high-temperature flue gas passing through the pipe section by utilizing the pressure difference between the inside of a hearth of the pulverized coal furnace 1 and the inside of a vertical flue 10, and comprises the following steps: the resistance of the high-temperature flue pipeline, the electric valve 3 for warm flue gas, the high-temperature dust remover 4, the hot air bellow 5 and the hot air distribution device 6.
Preferably, in order to ensure the safe and stable operation of the pulverized coal furnace, the pressure in the hearth of the pulverized coal furnace is kept between-150 Pa and-500 Pa, and the pressure range of the hot air mixing section of the vertical flue 10 is determined according to the resistance characteristics of the high-temperature flue gas pipeline, the warm flue gas electric valve 3, the high-temperature dust remover 4, the hot air bellow 5 and the hot air distribution device 6.
Raw flue gas to be treated enters a raw flue gas side 9 of the GGH heat exchanger through a flue gas pipeline, and enters a vertical flue 10 after heat exchange. An electric air damper 8 is arranged on the flue connected with the inlet of the original flue gas side 9 of the GGH heat exchanger.
A pressure monitoring device is arranged at the hot air mixing section of the vertical flue 10, and the pressure of the hot air mixing section of the vertical flue can be adjusted by adjusting the electric adjusting air door 8, so that the pressure value is in the determined pressure range.
After the pressure is stabilized by the above adjustment, the pulverized coal furnace 1 starts ignition and starts the combustion fan 7, and the pulverized coal furnace 1 starts to operate. The combustion-supporting fan 7 extracts flue gas from an outlet pipe at the raw flue gas side 9 of the GGH heat exchanger and conveys the flue gas to the pulverized coal furnace 1 through a flue gas pipeline.
The high-temperature flue gas generated by the pulverized coal furnace 1 passes through the high-temperature dust remover 4 to remove part of dust before being mixed into the original flue gas. The temperature of high-temperature flue gas generated by the pulverized coal furnace reaches 600-800 ℃, and the high-temperature dust collector 4 can adopt a high-temperature cyclone dust collector or a high-temperature ceramic filter lined with refractory materials.
The high-temperature flue gas treated by the high-temperature dust remover 4 is sent into a vertical flue 10 through a high-temperature flue gas pipeline, a hot air bellow 5 and a hot air distribution device 6, and is mixed with the original flue gas to realize the temperature rise of the flue gas.
After the flue gas is heated to the designed reaction temperature, a denitration reducing agent is provided for the flue gas through the ammonia injection grid 14, the uniformly mixed flue gas enters the SCR reactor 12, and the denitration reaction is completed in the SCR reactor 12. And the denitrated flue gas enters a subsequent desulfurization and dust removal device through a flue gas pipeline after being subjected to heat exchange by the GGH heat exchanger, and finally reaches the standard and is discharged.
In order to deal with emergency, a high-temperature flue gas electric valve 3 is arranged on a high-temperature flue gas pipeline from an outlet of the pulverized coal furnace 1 to the high-temperature dust remover 4, and a diffusing pipe and a diffusing valve 2 are arranged on a high-temperature flue between the pulverized coal furnace 1 and the high-temperature flue gas electric valve 3. When the main flue gas system is abnormal (such as the fan of the main flue gas system is suddenly stopped due to a fault), the combustion-supporting fan 7 is stopped in an interlocking manner, the high-temperature flue gas electric valve 3 is closed, and residual flue gas of the pulverized coal furnace is temporarily discharged through the diffusing pipe and the diffusing valve 2.
The method for heating SCR denitration flue gas comprises the following specific steps and parameters:
after the system starts to introduce smoke, the raw smoke enters a subsequent desulfurization and dust removal device after passing through an electric damper 8, a raw smoke side 9 of a GGH heat exchanger, a vertical flue 10, a static mixer 11, an SCR reactor 12 and a clean smoke side 13 of the GGH heat exchanger in sequence.
A flue gas pressure monitoring point is arranged at an outlet flue gas pipeline of a raw flue gas side 9 of the GGH heat exchanger, an electric damper 8 is arranged at an inlet flue gas pipeline of the raw flue gas side 9 of the GGH heat exchanger, and after the system is filled with flue gas, the pressure at the outlet flue gas pipeline of the raw flue gas side 9 of the GGH heat exchanger is controlled within the range of-1500 Pa to-2000 Pa by adjusting the electric damper 4.
Starting the pulverized coal furnace 1, controlling the pressure in the furnace chamber within the range of-50 Pa to-200 Pa to ensure the safe and stable operation of the pulverized coal furnace, enabling the high-temperature flue gas at 600-800 ℃ generated by the pulverized coal furnace 1 to sequentially pass through the high-temperature flue, the high-temperature dust remover 4, the hot air bellow 5 and the hot air distribution device 6 into the vertical flue 10 by virtue of the pressure difference between the furnace chamber and the vertical flue 10, mixing with the raw flue gas, and starting to heat the flue gas.
The system gradually raises the temperature of the flue gas by means of the flue gas heating device and the GGH heat exchanger until the temperature of the flue gas in the SCR reactor 12 reaches the designed reaction temperature (310-340 ℃), and the heat supply quantity of the pulverized coal furnace 1 is adjusted by adjusting the coal supply quantity and the combustion-supporting air quantity of the pulverized coal furnace, so that the temperature of the flue gas is stabilized at the designed value.
After the flue gas temperature of the system is stable, the inlet flue gas temperature of the original flue gas side 9 of the GGH heat exchanger is 150-160 ℃, and the outlet flue gas temperature of the original flue gas side 9 of the GGH heat exchanger is 285-305 ℃; the inlet flue gas temperature of the clean flue gas side 13 of the GGH heat exchanger is 310-330 ℃, and the outlet flue gas temperature of the clean flue gas side 13 of the GGH heat exchanger is 180-190 ℃.
After the temperature of the flue gas in the SCR reactor 12 reaches the design temperature (310-340 ℃), the reducing agent required for reaction is provided for the flue gas through the ammonia injection grid 14, and the reducing agent is mixed with the raw flue gas and then uniformly distributed through the mixing action of the static mixer 11 and the flow guide device in the flue.
After the above process, the flue gas with denitration reaction conditions enters the SCR reactor 12, the denitration reaction is completed under the action of the catalyst, the denitrated flue gas enters the clean flue gas side 13 of the GGH heat exchanger, and the denitrated flue gas enters the subsequent desulfurization and dust removal device through the flue gas pipeline after heat exchange.
In order to deal with emergency, a high-temperature flue gas electric valve 3 is arranged on a high-temperature flue gas pipeline from an outlet of the pulverized coal furnace 1 to the high-temperature dust remover 4, and a diffusing pipe and a diffusing valve 2 are arranged on a high-temperature flue between the pulverized coal furnace 1 and the high-temperature flue gas electric valve 3. When the main flue gas system is abnormal (such as the fan of the main flue gas system is suddenly stopped due to a fault), the combustion-supporting fan 7 is stopped in an interlocking manner, the high-temperature flue gas electric valve 3 is closed, and residual flue gas of the pulverized coal furnace is temporarily discharged through the diffusing pipe and the diffusing valve 2.
Claims (6)
1. The utility model provides an use buggy stove heating SCR denitration flue gas device which characterized in that: the device comprises a pulverized coal furnace (1), a bleeding valve (2), a high-temperature flue gas electric valve (3), a high-temperature dust remover (4), a hot air bellow (5), a hot air distribution device (6), a combustion fan (7), an electric air damper (8), a GGH heat exchanger raw flue gas side (9), a vertical flue (10), a static mixer (11), an SCR reactor (12), a GGH heat exchanger purified flue gas side (13) and an ammonia injection grid (14);
the pulverized coal furnace (1) is connected with a high-temperature dust remover (4) through a bleeding valve (2) and a high-temperature flue gas electric valve (3), the high-temperature dust remover (4) is connected with a hot air bellow (5), the hot air bellow (5) is connected with a vertical flue (10) through a hot air distribution device (6), the vertical flue (10) is connected with the pulverized coal furnace (1) through a combustion fan (7), an electric adjusting air door (8) is connected with a GGH heat exchanger raw flue gas side (9) through a flue, the GGH heat exchanger raw flue gas side (9) is connected with the vertical flue (10), the hot air distribution device (6) is positioned on the GGH heat exchanger raw flue gas side (9), an ammonia injection grid (14) is positioned above the hot air distribution device (6), a static mixer (11) is positioned above the ammonia injection grid (14), and the ammonia injection grid (14) and the static mixer (11) are both installed in the vertical flue (10), one end of the SCR reactor (12) is connected with the other end of the vertical flue (10), and the SCR reactor (12) is connected with the clean flue gas side (13) of the GGH heat exchanger.
2. A method for heating SCR denitration flue gas by a pulverized coal furnace is characterized by comprising the following steps:
after the flue gas starts to be introduced, the raw flue gas enters a subsequent desulfurization and dust removal device after passing through an electric damper (8), a GGH heat exchanger raw flue gas side (9), a vertical flue (10), a static mixer (11), an SCR reactor (12) and a GGH heat exchanger clean flue gas side (13) in sequence;
secondly, a flue gas pressure monitoring point is arranged at an outlet flue gas pipeline of the original flue gas side (9) of the GGH heat exchanger, an electric adjusting air door (8) is arranged at an inlet flue gas pipeline of the original flue gas side (9) of the GGH heat exchanger, and after the system is filled with flue gas, the pressure at the outlet flue gas pipeline of the original flue gas side (9) of the GGH heat exchanger is controlled within a set range by adjusting the electric adjusting air door (4);
step three, starting the pulverized coal furnace (1), controlling the pressure in the hearth within a set range, enabling high-temperature flue gas generated by the pulverized coal furnace (1) to sequentially pass through a high-temperature flue, a high-temperature dust collector (4), a hot air bellow (5) and a hot air distribution device (6) by virtue of the pressure difference between the hearth and a vertical flue (10) to enter the vertical flue (10), mixing with raw flue gas, and starting to heat the flue gas;
step four, the system gradually heats up the flue gas by means of a flue gas heating device and a GGH heat exchanger until the temperature of the flue gas in the SCR reactor (12) reaches a designed reaction temperature, and adjusts the heat supply amount of the pulverized coal furnace (1) by adjusting the coal supply amount and the combustion-supporting air amount of the pulverized coal furnace to stabilize the temperature of the flue gas at a designed value;
fifthly, the flue gas temperature of the system is stable, after the flue gas temperature in the SCR reactor (12) reaches the design temperature, reducing agents required for reaction are provided for the flue gas through an ammonia spraying grid (14), and the reducing agents are mixed with the raw flue gas and then uniformly distributed through the mixing action of a static mixer (11) and a flow guide device in a flue;
step six, after the process, the flue gas with denitration reaction conditions enters an SCR reactor (12), denitration reaction is completed under the action of a catalyst, the denitrated flue gas enters a clean flue gas side (13) of a GGH heat exchanger, and the denitrated flue gas enters a subsequent desulfurization and dust removal device through a flue gas pipeline after heat exchange;
seventhly, in order to deal with emergency situations, a high-temperature flue gas electric valve (3) is arranged on a high-temperature flue gas pipeline from the outlet of the pulverized coal furnace (1) to the high-temperature dust remover (4), and a diffusing pipe and a diffusing valve (2) are arranged on a high-temperature flue between the pulverized coal furnace (1) and the high-temperature flue gas electric valve (3); when the main flue gas system is abnormal, the combustion-supporting fan (7) is stopped and the high-temperature flue gas electric valve (3) is closed in an interlocking manner, and residual flue gas of the pulverized coal furnace is temporarily discharged through the diffusing pipe and the diffusing valve (2).
3. The method for heating SCR denitration flue gas by using pulverized coal furnace as claimed in claim 2, characterized in that: the pressure setting range of the outlet flue gas pipeline at the raw flue gas side 9 of the GGH heat exchanger is-1500 Pa to-2000 Pa.
4. The method for heating SCR denitration flue gas by using pulverized coal furnace as claimed in claim 2, characterized in that: the pressure in the hearth is controlled within a set range of-50 Pa to-200 Pa.
5. The method for heating SCR denitration flue gas by using pulverized coal furnace as claimed in claim 2, characterized in that: the designed reaction temperature in the SCR reactor 12 is 310-340 ℃.
6. The method for heating SCR denitration flue gas by using pulverized coal furnace as claimed in claim 2, characterized in that: the flue gas temperature of the system is stable, namely the flue gas temperature of an inlet 9 at the raw flue gas side of the GGH heat exchanger is 150-160 ℃, and the flue gas temperature of an outlet 9 at the raw flue gas side of the GGH heat exchanger is 285-305 ℃; the inlet flue gas temperature of the clean flue gas side 13 of the GGH heat exchanger is 310-330 ℃, and the outlet flue gas temperature of the clean flue gas side 13 of the GGH heat exchanger is 180-190 ℃.
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| CN114618274A (en) * | 2022-02-21 | 2022-06-14 | 柳州钢铁股份有限公司 | Method for preventing corrosion of metal heat exchanger |
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2021
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114618274A (en) * | 2022-02-21 | 2022-06-14 | 柳州钢铁股份有限公司 | Method for preventing corrosion of metal heat exchanger |
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