CN111068477A - System and method for relieving blockage of air preheater through flue gas recirculation - Google Patents
System and method for relieving blockage of air preheater through flue gas recirculation Download PDFInfo
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- CN111068477A CN111068477A CN201911345571.8A CN201911345571A CN111068477A CN 111068477 A CN111068477 A CN 111068477A CN 201911345571 A CN201911345571 A CN 201911345571A CN 111068477 A CN111068477 A CN 111068477A
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- flue gas
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
- B01D53/86—Catalytic processes
- B01D53/8621—Removing nitrogen compounds
- B01D53/8625—Nitrogen oxides
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2258/00—Sources of waste gases
- B01D2258/02—Other waste gases
- B01D2258/0283—Flue gases
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Abstract
The invention discloses a system and a method for relieving blockage of an air preheater through flue gas recirculation, relates to the field of industrial waste gas purification, environmental protection and energy, and particularly relates to a system and a method for relieving blockage of an air preheater through flue gas recirculation. According to the invention, high-temperature flue gas is introduced into the flue gas recirculation flue to heat and evaporate high-viscosity ammonium bisulfate, so that excessive local ammonia escape in the denitration process of the SCR denitration reactor is relieved to generate high-concentration ammonium bisulfate, the blockage of the air preheater is effectively relieved, and the pressure difference of the air preheater is prevented from rising. Compared with other methods for relieving the blockage of the air preheater, the method introduces high-temperature flue gas through the flue gas recirculation flue to directly heat and relieve the blockage of the air preheater, and has the advantages of low investment cost and operation cost for modification, energy conservation, consumption reduction and wide application prospect.
Description
Technical Field
The invention relates to the field of industrial waste gas purification, environmental protection and energy, in particular to a system and a method for relieving blockage of an air preheater through flue gas recirculation.
Background
At present, coal-fired power generating units are reformed by ultralow emission, wherein the removal of nitrogen oxides is mainly completed by an SCR denitration technology. The SCR denitration spraying means that ammonia gas and nitrogen oxide in flue gas are sprayed into an SCR reactor to perform oxidation reduction reaction under the catalytic action of a catalyst so as to achieve the aim of removing the nitrogen oxide. In the method, when the nitrogen oxides are removed, unreacted ammonia gas escapes from the SCR outlet and is mixed with SO in the flue gas3The reaction takes place to produce highly viscous ammonium bisulfate. When the load of part of coal-fired units changes, due to the defects of ammonia injection valve control, SCR flow field and the like, the phenomenon of large ammonia escape caused by excessive ammonia injection can occur, more fly ash in ammonium bisulfate bonded flue gas is generated and attached to a heat exchange unit of an air preheater to block the air preheater, the load of the units is limited when the fly ash is serious, the generated energy is reduced, the substance is volatile under the high-temperature condition, and the blocking degree of the air preheater can be relieved by a temperature rise method.
Disclosure of Invention
In order to solve the problems, the invention provides a system and a method for relieving the blockage of an air preheater by flue gas recirculation, which have the advantages of low investment cost and operation cost, capability of effectively relieving the blockage of the air preheater, energy conservation and consumption reduction.
The invention relates to a system for relieving blockage of an air preheater by flue gas recirculation, which comprises a boiler, an economizer, an SCR (selective catalytic reduction) denitration reactor and the air preheater which are sequentially communicated through a flue, and further comprises a flue gas recirculation flue, wherein the flue gas recirculation flue comprises a hot flue gas recirculation flue and a cold flue gas recirculation flue which are mutually communicated; and a circulating fan is arranged on the cold flue gas recirculation flue.
Preferably, the air preheater is a rotary air preheater, a primary air channel, a secondary air channel, a flue gas channel and a recirculation flue gas channel are arranged in the air preheater, and the primary air channel, the secondary air channel, the flue gas channel and the recirculation flue gas channel are separated from each other through metal partition plates.
Preferably, the hot flue gas recirculation flue is provided with a recirculation flue gas inlet gate, and the cold flue gas recirculation flue is provided with a recirculation flue gas outlet gate.
Preferably, a recirculation flue adjusting valve is arranged on the hot flue gas recirculation flue between the recirculation flue gas inlet gate and the air preheater.
Preferably, the circulation fan is arranged on the cold flue gas recirculation flue between the air preheater and the recirculated flue gas outlet gate.
A method for relieving blockage of an air preheater by flue gas recirculation uses a system for relieving blockage of the air preheater by flue gas recirculation to relieve blockage of the air preheater, and comprises the following steps: when the unit is in low load or the temperature of the cold end of the air preheater is monitored to be lower, starting a hot air recirculation system; and opening a recirculation flue gas inlet gate, a recirculation flue gas outlet gate and a recirculation flue regulating valve in sequence, starting a circulation fan, leading hot flue gas from an economizer inlet to enter a recirculation flue gas channel on the air preheater through a hot flue gas recirculation flue to heat a heat storage element so as to improve the cold end temperature of the air preheater, leading the heat-exchanged flue gas out of a cold flue gas recirculation flue to an inlet of the SCR denitration reactor, and leading the heat-exchanged flue gas into the SCR denitration reactor together with the original flue gas to participate in denitration reaction.
Preferably, the circulating rotation sequence of the air preheater is a flue gas channel, a primary air channel, a secondary air channel, a recirculation flue gas channel and a flue gas channel in sequence.
The high-temperature flue gas is introduced into the flue gas recirculation flue to heat and evaporate high-viscosity ammonium bisulfate, so that the phenomenon that local ammonia escapes excessively to generate high ammonium bisulfate in the denitration process of the SCR denitration reactor is relieved, the blockage of the air preheater is effectively relieved, and the pressure difference of the air preheater is prevented from rising. Compared with other methods for relieving the blockage of the air preheater, the method introduces high-temperature flue gas through the flue gas recirculation flue to directly heat and relieve the blockage of the air preheater, has the advantages of low reconstruction investment cost and operation cost, high reliability, energy conservation, consumption reduction and the like, and has wide application prospect.
Drawings
FIG. 1 is a schematic view of the structure of the present invention.
Fig. 2 is a schematic diagram of the arrangement of channels of the air preheater.
Reference numerals: 1-an economizer, 2-an SCR denitration reactor, 3-an air preheater, 4-a recirculating flue gas inlet gate, 5-a recirculating flue gas adjusting valve, 6-a circulating fan, 7-a recirculating flue gas outlet gate, 8-a flue gas channel, 9-a primary air channel, 10-a secondary air channel, 11-a recirculating flue gas channel, 12-a hot flue gas recirculating flue gas and 13-a cold flue gas recirculating flue gas.
Detailed Description
The invention relates to a system for relieving blockage of an air preheater 3 by flue gas recirculation, which comprises a boiler, an economizer 1, an SCR denitration reactor 2 and the air preheater 3 which are sequentially communicated through a flue, and further comprises a flue gas recirculation flue, wherein the flue gas recirculation flue comprises a hot flue gas recirculation flue 12 and a cold flue gas recirculation flue 13 which are communicated with each other, a recirculation flue gas channel 11 is arranged on the air preheater 3, one end of the hot flue gas recirculation flue 12 is communicated with the flue between the boiler and the economizer 1, the other end of the hot flue gas recirculation flue is communicated with the lower end of the recirculation flue gas channel 11 on the air preheater 3, and the upper end of the recirculation flue gas channel 11 is communicated with the flue between the economizer 1 and the SCR denitration reactor 2 through the cold flue gas recirculation flue 13; and a circulating fan 6 is arranged on the cold flue gas recirculation flue 13.
The air preheater 3 is a rotary air preheater 3, a primary air channel 9, a secondary air channel 10, a flue gas channel 8 and a recirculation flue gas channel 11 are arranged in the air preheater 3, and the primary air channel 9, the secondary air channel 10, the flue gas channel 8 and the recirculation flue gas channel 11 are arranged in a separated mode through metal partition plates.
A recirculation flue gas inlet gate 4 is arranged on the hot flue gas recirculation flue 12, and a recirculation flue gas outlet gate 7 is arranged on the cold flue gas recirculation flue 13.
A recirculation flue regulating valve 5 is arranged on a hot flue gas recirculation flue 12 between the recirculation flue gas inlet gate 4 and the air preheater 3.
The circulation fan 6 is arranged on the cold flue gas recirculation flue 13 between the air preheater 3 and the recirculated flue gas outlet gate 7.
A method for relieving the blockage of an air preheater 3 by flue gas recirculation uses a system for relieving the blockage of the air preheater 3 by flue gas recirculation to relieve the blockage of the air preheater 3, and comprises the following steps: when the unit is in low load or the temperature of the cold end of the air preheater 3 is monitored to be lower, starting a hot air recirculation system; the recycling flue gas inlet gate 4, the recycling flue gas outlet gate 7 and the recycling flue adjusting valve 5 are opened in sequence, the circulating fan 6 is started, hot flue gas enters the recycling flue gas channel 11 on the air preheater 3 from the inlet of the economizer 1 through the recycling flue 12 to heat the heat storage element so as to improve the temperature of the cold end of the air preheater 3, and the flue gas after heat exchange is led out to the inlet of the SCR denitration reactor 2 through the recycling flue 13 of the cold flue gas and enters the SCR denitration reactor 2 together with the original flue gas to participate in denitration reaction.
The air preheater 3 sequentially comprises a flue gas channel 8, a primary air channel 9, a secondary air channel 10, a recirculation flue gas channel 11 and a flue gas channel 8 in a circulating rotation sequence.
The high-temperature flue gas is introduced into the flue gas recirculation flue to heat and evaporate high-viscosity ammonium bisulfate, so that the phenomenon that local ammonia escapes too much in the denitration process of the SCR denitration reactor 2 to generate high ammonium bisulfate is relieved, the blockage of the air preheater 3 is effectively relieved, and the pressure difference of the air preheater 3 is prevented from rising. Compared with other methods for relieving the blockage of the air preheater 3, the method introduces high-temperature flue gas through the flue gas recirculation flue to directly heat and relieve the blockage of the air preheater 3, has the advantages of low reconstruction investment cost and operation cost, high reliability, energy conservation, consumption reduction and the like, and has wide application prospect.
Claims (7)
1. A system for relieving blockage of an air preheater through flue gas recirculation comprises a boiler, an economizer (1), an SCR denitration reactor (2) and an air preheater (3) which are sequentially communicated through a flue, and is characterized by further comprising a flue gas recirculation flue, wherein the flue gas recirculation flue comprises a hot flue gas recirculation flue (12) and a cold flue gas recirculation flue (13) which are communicated with each other, a recirculation flue gas channel (10) is arranged on the air preheater (3), one end of the hot flue gas recirculation flue (12) is communicated with the flue between the boiler and the economizer (1), the other end of the hot flue gas recirculation flue (12) is communicated with the lower end of the recirculation flue gas channel (10) on the air preheater (3), and the upper end of the recirculation flue gas channel (10) is communicated with the flue between the economizer (1) and the SCR denitration reactor (2) through the cold flue gas recirculation flue (13); and a circulating fan (6) is arranged on the cold flue gas recirculation flue (13).
2. The system for relieving the blockage of the air preheater in the flue gas recirculation manner according to claim 1, wherein the air preheater (3) is a rotary air preheater (3), a primary air channel (9), a secondary air channel (10), a flue gas channel (8) and a recirculation flue gas channel (10) are arranged in the air preheater (3), and the primary air channel (9), the secondary air channel (10), the flue gas channel (8) and the recirculation flue gas channel (10) are separated from each other by metal partition plates.
3. The system for mitigating air preheater blockage according to the claim 2, characterized in that the hot flue gas recirculation flue (12) is provided with a recirculation flue gas inlet gate (4), and the cold flue gas recirculation flue (13) is provided with a recirculation flue gas outlet gate (7).
4. A system for the mitigation of the blockage in the air preheater according to the claim 3, characterized in that the recirculation flue gas regulating valve (5) is arranged on the hot flue gas recirculation flue (12) between the recirculation flue gas inlet gate (4) and the air preheater (3).
5. A system for the mitigation of the blockage of an air preheater according to claim 4, characterized in that the recirculation fan (6) is arranged on the cold flue gas recirculation flue (13) between the air preheater (3) and the recirculation flue gas outlet lock (7).
6. A method for alleviating the blockage of an air preheater by flue gas recirculation, which is characterized in that the blockage of the air preheater (3) is alleviated by using the system for alleviating the blockage of the air preheater by flue gas recirculation according to any one of claims 1 to 5, and the method comprises the following steps: when the unit is in low load or the temperature of the cold end of the air preheater (3) is monitored to be lower, starting a hot air recirculation system; open recirculation flue gas entry gate (4) in proper order, recirculation exhanst gas outlet gate (7) and recirculation flue damper (5), start circulating fan (6), hot flue gas is got into recirculation flue gas passageway (10) heating heat accumulation component on air preheater (3) through hot flue gas recirculation flue (12) by economizer (1) entry and is improved air preheater (3) cold junction temperature, flue gas after the heat transfer is drawn forth to the entrance of SCR denitration reactor (2) through cold flue gas recirculation flue (13), get into SCR denitration reactor (2) with former flue gas and participate in the denitration reaction.
7. The method for alleviating the blockage of the air preheater by flue gas recirculation according to claim 6, wherein the air preheater (3) circularly rotates in sequence of a flue gas channel (8), a primary air channel (9), a secondary air channel (10), a recirculation flue gas channel (10) and a flue gas channel (8).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911345571.8A CN111068477A (en) | 2019-12-24 | 2019-12-24 | System and method for relieving blockage of air preheater through flue gas recirculation |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911345571.8A CN111068477A (en) | 2019-12-24 | 2019-12-24 | System and method for relieving blockage of air preheater through flue gas recirculation |
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| CN111068477A true CN111068477A (en) | 2020-04-28 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201911345571.8A Pending CN111068477A (en) | 2019-12-24 | 2019-12-24 | System and method for relieving blockage of air preheater through flue gas recirculation |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023091442A1 (en) * | 2021-11-16 | 2023-05-25 | Siemens Energy, Inc. | Method and device to improve the performance of a power plant integrated with a thermal energy storage system |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105042623A (en) * | 2015-08-18 | 2015-11-11 | 德清金烨电力科技有限公司 | Air pre-heater |
| CN107842874A (en) * | 2017-10-26 | 2018-03-27 | 中国大唐集团科学技术研究院有限公司华东分公司 | A kind of primary and secondary air heat distribution regulating system and method |
| CN109539298A (en) * | 2018-12-13 | 2019-03-29 | 杭州华电能源工程有限公司 | A kind of anti-air preheater cold end ABS blocking thermal wind sensor system and its application method |
| CN109882879A (en) * | 2019-04-03 | 2019-06-14 | 华能国际电力股份有限公司玉环电厂 | A kind of full working scope denitrating flue gas and air preheater anti-blocking system |
| JP2019143918A (en) * | 2018-02-22 | 2019-08-29 | 三菱日立パワーシステムズ株式会社 | Rotary air preheater, boiler system and block prevention method of rotary air preheater |
| CN212236676U (en) * | 2019-12-24 | 2020-12-29 | 中国大唐集团科学技术研究院有限公司西北电力试验研究院 | System for air preheater blocks up is alleviated in flue gas recirculation |
-
2019
- 2019-12-24 CN CN201911345571.8A patent/CN111068477A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105042623A (en) * | 2015-08-18 | 2015-11-11 | 德清金烨电力科技有限公司 | Air pre-heater |
| CN107842874A (en) * | 2017-10-26 | 2018-03-27 | 中国大唐集团科学技术研究院有限公司华东分公司 | A kind of primary and secondary air heat distribution regulating system and method |
| JP2019143918A (en) * | 2018-02-22 | 2019-08-29 | 三菱日立パワーシステムズ株式会社 | Rotary air preheater, boiler system and block prevention method of rotary air preheater |
| CN109539298A (en) * | 2018-12-13 | 2019-03-29 | 杭州华电能源工程有限公司 | A kind of anti-air preheater cold end ABS blocking thermal wind sensor system and its application method |
| CN109882879A (en) * | 2019-04-03 | 2019-06-14 | 华能国际电力股份有限公司玉环电厂 | A kind of full working scope denitrating flue gas and air preheater anti-blocking system |
| CN212236676U (en) * | 2019-12-24 | 2020-12-29 | 中国大唐集团科学技术研究院有限公司西北电力试验研究院 | System for air preheater blocks up is alleviated in flue gas recirculation |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023091442A1 (en) * | 2021-11-16 | 2023-05-25 | Siemens Energy, Inc. | Method and device to improve the performance of a power plant integrated with a thermal energy storage system |
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