CN210951277U - Flue gas recirculation system - Google Patents
Flue gas recirculation system Download PDFInfo
- Publication number
- CN210951277U CN210951277U CN201921459420.0U CN201921459420U CN210951277U CN 210951277 U CN210951277 U CN 210951277U CN 201921459420 U CN201921459420 U CN 201921459420U CN 210951277 U CN210951277 U CN 210951277U
- Authority
- CN
- China
- Prior art keywords
- flue
- baffle
- flue gas
- air duct
- gas recirculation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn - After Issue
Links
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 title claims abstract description 39
- 239000003546 flue gas Substances 0.000 title claims abstract description 39
- 206010022000 influenza Diseases 0.000 claims description 6
- 238000010438 heat treatment Methods 0.000 description 11
- 239000000779 smoke Substances 0.000 description 9
- 238000010521 absorption reaction Methods 0.000 description 6
- 238000001816 cooling Methods 0.000 description 6
- 230000005855 radiation Effects 0.000 description 4
- 238000003303 reheating Methods 0.000 description 4
- 239000003245 coal Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 229910000831 Steel Inorganic materials 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 238000007789 sealing Methods 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 230000028016 temperature homeostasis Effects 0.000 description 1
- 238000005496 tempering Methods 0.000 description 1
Images
Abstract
The utility model discloses a flue gas recirculation system, first way, include from the first to fifth flue G1~ G5 that leads to the furnace lower part of air preheater entry flue, lead out first flue G1 from air preheater entry flue, first flue, flue gas recirculation fan 1, second flue G2, second baffle 2, third flue G3, third baffle 3, fourth flue G4 series connection in proper order, draw out from fourth flue G4 branch multichannel fifth flue G5 and insert furnace; in the second path, a cold air duct A1 led out from an air preheater inlet air duct is connected with a fourth baffle 4, the fourth baffle is connected with a second air duct, and the second air duct is communicated with the middle part of a third flue; and in the third path, a hot air duct A3 led out from an air preheater outlet duct is connected with a fifth baffle 5, the fifth baffle is connected with a fourth air duct, and the fourth air duct is communicated with the middle part of a fourth flue.
Description
Technical Field
The utility model relates to a flue gas recirculation system of coal fired power plant boiler.
Background
At present, the difference between the fuel combusted by the domestic coal-electric boiler and the originally designed coal type is large, including various conditions in the operation process, so that the temperature of the reheated steam in the operation process, especially under low load, can not reach the designed value.
In order to adapt to the situation that the steam temperature is insufficient due to the change of coal types, loads and the like, under the condition that the temperature adjustment is not obvious through the swinging of the combustor under the low load, an adjusting means is needed to obviously improve the temperature of the reheated steam.
SUMMERY OF THE UTILITY MODEL
The to-be-solved technical problem of the utility model is: the problem that the temperature of the reheated steam of the double reheat boiler is not enough is solved.
In order to solve the technical problem, the technical scheme of the utility model is to provide a scheme of a flue gas recirculation system, the first path comprises a first flue to a fifth flue leading from an inlet flue of an air preheater to the lower part of a hearth, the first flue is led from the inlet flue of the air preheater, the first flue, a flue gas recirculation fan, the second flue, a second baffle, a third flue, a third baffle and a fourth flue are sequentially connected in series, and the fourth flue is divided into a plurality of paths of fifth flues to be led out and connected into the hearth; the second path is characterized in that a cold air channel led out from an air preheater inlet air channel is connected with a fourth baffle plate, the fourth baffle plate is connected with a second air channel, and the second air channel is communicated with the middle part of a third flue; and the third path is characterized in that a hot air channel led out from an air preheater outlet air channel is connected with a fifth baffle plate, the fifth baffle plate is connected with a fourth air channel, and the fourth air channel is communicated with the middle part of a fourth air channel. The principle of flue gas recirculation thermoregulation is that partial flue gas at the tail part of a boiler and at the inlet of an air preheater is fed from the lower part of a hearth through a flue gas recirculation fan, wherein two sets of baffles are arranged on a pipeline of recirculation air and the lower part of the hearth and used for isolating the hearth from the flue gas recirculation fan and preventing the hearth from being damaged by high-temperature reverse connection.
Preferably, when the boiler is in high load and the flue gas recirculation is not used, the fan is stopped, the two baffles are closed, and one path of cold air from the inlet of the air preheater is introduced into the pipeline between the two baffles, so that the functions of sealing the pipeline and cooling and protecting the flue gas recirculation fan are achieved.
Preferably, when the boiler is in high load and the flue gas is not recycled, the fan is stopped, the two baffles are closed, and one path of hot air from the outlet of the air preheater is introduced into the pipeline between the lower part of the hearth and the baffles, so that the functions of cooling the pipeline and cooling the protective baffles are achieved.
The utility model has the advantages that: partial flue gas at the tail part of the boiler and the inlet of the air preheater is fed from the lower part of the hearth through a flue gas recirculation fan to reduce the combustion temperature in the boiler so as to reduce the radiation heat exchange quantity of the hearth, increase the heat brought into the convection heating surface, increase the flue gas flow velocity of the convection heating surface and improve the convection heat exchange coefficient, thereby finally changing the heat absorption quantity ratio of the radiation heating surface and the convection heating surface of the boiler. The temperature of the hearth is reduced along with the increase of the amount of the recycled flue gas, so that the radiation heat absorption is reduced, but the temperature change of the flue gas at the outlet of the hearth is not large. The heat absorption capacity of the convection heating surface is increased along with the increase of the smoke quantity, so that the purpose of adjusting the steam temperature is achieved, the smoke heat extracted in the mode is high, the influence on the smoke temperature of the hearth outlet is small, and the adjusting effect is good.
Drawings
FIG. 1, a flue gas recirculation system of the present invention;
the reference numerals are explained below: the device comprises a flue gas recirculation fan 1, second to fifth baffles 2 to 5, first to seventh flues G1 to G5, a cold air duct A1, a second air duct A2, a hot air duct A3 and a fourth air duct A4.
Detailed Description
The present invention will be described in more detail with reference to the following embodiments, but the present invention is not limited to the following examples.
The embodiment of the utility model provides a:
a flue gas recirculation system comprises first to fifth flues G1-G5 led to the lower part of a hearth from an inlet flue of an air preheater, a cold air duct A1 led out from an inlet air duct of the air preheater, a hot air duct A3 led out from an outlet air duct of the air preheater, a flue gas recirculation fan 1, a second baffle plate 2, a third baffle plate 3, a fourth baffle plate 4 and a fifth baffle plate 5.
A first flue G1 is led out from an inlet flue of the air preheater and is connected into a flue gas recirculation fan 1, the flue gas recirculation fan 1 is connected with a second baffle 2 through being connected with a second flue G2, the second baffle 2 is connected with a third baffle 3 through being connected with a third flue G3, the third baffle 3 is connected with a fourth flue G4, the fourth flue G4 is connected with a fifth flue G5, and the flue G4 is divided into multiple paths of the fifth flues G5 to be led out and connected into a hearth.
When the boiler is in high load and the flue gas recirculation is not used, before the flue gas recirculation fan 1 is shut down, the second baffle 2 and the third baffle 3 are closed (namely the second baffle 2 and the third baffle 3 are closed and are both opened), the fourth baffle 4 on the cold air channel A1 from the inlet of the air preheater is opened, the air is introduced to the third flue G3 between the second baffle 2 and the third baffle 3 through the cold air channel A1 from the inlet of the air preheater, the fifth baffle 5 on the hot air channel A3 from the outlet of the air preheater is opened at the same time, the air is introduced to the fourth flue G4 through the hot air channel A3 from the outlet of the air preheater, and then the second baffle 2 and the third baffle 3 are closed. At the moment, the pressure of the cold air duct A1 and the pressure of the hot air duct A3 are higher than that of the smoke of the third flue G3 and the smoke of the fourth flue G4, the cold air duct A1 can play a role in sealing the second duct G2 and cooling and protecting the smoke recirculation fan 1, and the hot air duct A3 plays a role in preventing the hearth from tempering, cooling the fourth fifth ducts G4-G5 and cooling and protecting the third baffle 3.
When the boiler is low-load and the flue gas recirculation is started, the second baffle 2 and the third baffle 3 are firstly opened, the flue gas recirculation fan 1 is then opened, and then the fourth baffle 4 and the fifth baffle 5 are closed.
Through the implementation of the flue gas recirculation scheme, when the boiler is in low load, the radiant heat exchange quantity of the hearth can be reduced, so that the heat brought into the convection heating surface is increased, the flue gas flow velocity of the convection heating surface is increased, the convection heat exchange coefficient is improved, and the heat absorption quantity ratio of the boiler radiant to the convection heating surface is finally changed. The temperature of the hearth is reduced along with the increase of the amount of the recycled flue gas, so that the radiation heat absorption is reduced, but the temperature change of the flue gas at the outlet of the hearth is not large. The heat absorption capacity of the convection heating surface is increased along with the increase of the smoke quantity, so that the purpose of adjusting the temperature of the reheated steam is achieved, the smoke heat extracted in the mode is high, the influence on the smoke temperature of the hearth outlet is small, and the adjusting effect is good.
The domestic secondary reheating unit is accepted by wide users due to high efficiency, but the secondary reheating unit is difficult to reach the steam temperature through a conventional temperature adjusting means under partial load due to high parameters and the addition of a secondary reheating system, and can be improved only by arranging more heating surfaces, so that the consumption of steel is large. And the flue gas recirculation system is adopted, the flow velocity of the flue gas under partial load can be effectively improved, the heat exchange effect is improved, the reheating steam temperature can be reached under the condition of less heating surface arrangement, the unit efficiency under low load of a power plant is improved, and the steel consumption is reduced for a boiler manufacturing unit. The flue gas recirculation system adopted by the patent has a more fully-equipped flue gas isolation measure, can ensure that the fan can be maintained on line without shutdown of the unit, is very favorable for the continuous operation of the unit, and avoids the economic loss caused by shutdown of the unit.
Although the present invention has been described with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (1)
1. A flue gas recirculation system, characterized by:
the first path comprises first to fifth flues (G1-G5) led to the lower part of the hearth from an inlet flue of the air preheater, the first flue (G1) is led out from the inlet flue of the air preheater, the first flue, the flue gas recirculation fan (1), the second flue (G2), the second baffle (2), the third flue (G3), the third baffle (3) and the fourth flue (G4) are sequentially connected in series, and the fourth flue (G4) is led out in multiple paths of the fifth flues (G5) and is connected into the hearth;
in the second path, a cold air duct (A1) led out from an air preheater inlet air duct is connected with a fourth baffle (4), the fourth baffle is connected with a second air duct (A2), and the second air duct is communicated with the middle part of a third air duct;
and in the third path, a hot air channel (A3) led out from an air preheater outlet air channel is connected with a fifth baffle (5), the fifth baffle is connected with a fourth air channel (A4), and the fourth air channel is communicated with the middle part of the fourth air channel.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921459420.0U CN210951277U (en) | 2019-09-03 | 2019-09-03 | Flue gas recirculation system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921459420.0U CN210951277U (en) | 2019-09-03 | 2019-09-03 | Flue gas recirculation system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN210951277U true CN210951277U (en) | 2020-07-07 |
Family
ID=71371715
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201921459420.0U Withdrawn - After Issue CN210951277U (en) | 2019-09-03 | 2019-09-03 | Flue gas recirculation system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN210951277U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110410771A (en) * | 2019-09-03 | 2019-11-05 | 上海锅炉厂有限公司 | A kind of flue gas recirculation system |
-
2019
- 2019-09-03 CN CN201921459420.0U patent/CN210951277U/en not_active Withdrawn - After Issue
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110410771A (en) * | 2019-09-03 | 2019-11-05 | 上海锅炉厂有限公司 | A kind of flue gas recirculation system |
| CN110410771B (en) * | 2019-09-03 | 2024-04-26 | 上海锅炉厂有限公司 | Flue gas recirculation system |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| AV01 | Patent right actively abandoned | ||
| AV01 | Patent right actively abandoned | ||
| AV01 | Patent right actively abandoned |
Granted publication date: 20200707 Effective date of abandoning: 20240426 |
|
| AV01 | Patent right actively abandoned |
Granted publication date: 20200707 Effective date of abandoning: 20240426 |