CN212236676U - System for air preheater blocks up is alleviated in flue gas recirculation - Google Patents
System for air preheater blocks up is alleviated in flue gas recirculation Download PDFInfo
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- CN212236676U CN212236676U CN201922344546.XU CN201922344546U CN212236676U CN 212236676 U CN212236676 U CN 212236676U CN 201922344546 U CN201922344546 U CN 201922344546U CN 212236676 U CN212236676 U CN 212236676U
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- flue gas
- flue
- air preheater
- recirculation
- gas recirculation
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Abstract
The utility model relates to a system and industrial waste gas purification environmental protection and energy field that air preheater blockked up are alleviated in flue gas recirculation, concretely relates to system that air preheater blockked up is alleviated in flue gas recirculation, including boiler, economizer, SCR denitration reactor and the air preheater that loops through the flue intercommunication, still include the flue gas recirculation flue, the flue gas recirculation flue includes the hot flue gas recirculation flue and the cold flue gas recirculation flue that communicate each other. The utility model discloses utilize flue gas recirculation flue to introduce high temperature flue gas heating evaporation high viscidity ammonium bisulfate, alleviate SCR denitration reactor denitration process local ammonia and escape the higher ammonium bisulfate of too big formation, effectively alleviate the jam of air preheater, avoid the rising of air preheater pressure differential. The utility model discloses a flue gas recirculation flue introduces high temperature flue gas direct heating and alleviates the air preheater and blocks up, and it is lower to reform transform investment cost, working costs, and application prospect is extensive.
Description
Technical Field
The utility model relates to an industrial waste gas purifies environmental protection and energy field, concretely relates to system that air preheater blockked up is alleviated in 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.
SUMMERY OF THE UTILITY MODEL
In order to solve the problem, the utility model provides a, investment cost and working costs are low, can effectively alleviate the air preheater and block up, and energy saving can consumption reduction's a flue gas recirculation alleviates the system that the air preheater blockked up.
The utility model relates to a system for air preheater is alleviated in flue gas recirculation blocks up, including boiler, economizer, SCR denitration reactor and the air preheater that loop through the flue intercommunication, still include the flue gas recirculation flue, the flue gas recirculation flue includes hot flue gas recirculation flue and the cold flue gas recirculation flue that communicates each other, be provided with recirculated flue gas passageway on the air preheater, the one end of hot flue gas recirculation flue is linked together with the flue between boiler and the economizer, and the other end is linked together with the lower extreme of recirculated flue gas passageway on the air preheater, and the upper end of recirculated flue gas passageway is linked together through the flue between cold flue gas recirculation flue and economizer and the SCR denitration reactor; 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 utility model discloses simple structure utilizes the flue gas recirculation flue to introduce high temperature flue gas heating evaporation high viscous ammonium bisulfate, alleviates the local ammonia escape of SCR denitration reactor denitration process and excessively generates higher ammonium bisulfate, effectively alleviates the jam of air preheater, avoids the rising of air preheater pressure differential. The utility model discloses a flue gas recirculation flue introduces high temperature flue gas direct heating and alleviates the air preheater and blocks up, and it is lower to reform transform investment cost, working costs, has high reliability, advantages such as energy saving and consumption reduction, and application prospect is extensive.
Drawings
Fig. 1 is a schematic structural diagram 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 utility model relates to a system that air preheater 3 blockked up is alleviated in flue gas recirculation, including the boiler, economizer 1, SCR denitration reactor 2 and the air preheater 3 that loop through the flue intercommunication, still include the flue gas recirculation flue, the flue gas recirculation flue includes hot flue gas recirculation flue 12 and the cold flue gas recirculation flue 13 of intercommunication each other, be provided with recirculation flue gas passageway 11 on the air preheater 3, the flue between one end and boiler and economizer 1 of hot flue gas recirculation flue 12 is linked together, and the other end is linked together with the lower extreme of recirculation flue gas passageway 11 on the air preheater 3, and the upper end of recirculation flue gas passageway 11 is linked together through cold flue gas recirculation flue 13 and the flue between economizer 1 and SCR denitration reactor 2; 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 by flue gas recirculation to relieve the 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 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 utility model discloses simple structure utilizes the flue gas recirculation flue to introduce high temperature flue gas heating evaporation high viscous ammonium bisulfate, alleviates 2 denitration process local ammonia of SCR denitration reactor and escapes the higher ammonium bisulfate of too big formation, effectively alleviates 3 clogs up of air preheater, avoids 3 pressure differentials of air preheater to rise. The utility model discloses a flue gas recirculation flue introduces high temperature flue gas direct heating and alleviates the jam of air preheater 3, and it is lower to reform transform investment cost, working costs, has high reliability, advantages such as energy saving and consumption reduction, and application prospect is extensive.
Claims (5)
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 (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 (12) 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).
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 (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 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).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201922344546.XU CN212236676U (en) | 2019-12-24 | 2019-12-24 | System for air preheater blocks up is alleviated in flue gas recirculation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201922344546.XU CN212236676U (en) | 2019-12-24 | 2019-12-24 | System for air preheater blocks up is alleviated in flue gas recirculation |
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| Publication Number | Publication Date |
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| CN212236676U true CN212236676U (en) | 2020-12-29 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201922344546.XU Expired - Fee Related CN212236676U (en) | 2019-12-24 | 2019-12-24 | System for air preheater blocks up is alleviated in flue gas recirculation |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111068477A (en) * | 2019-12-24 | 2020-04-28 | 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 and method for relieving blockage of air preheater through flue gas recirculation |
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2019
- 2019-12-24 CN CN201922344546.XU patent/CN212236676U/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111068477A (en) * | 2019-12-24 | 2020-04-28 | 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 and method for relieving blockage of air preheater through flue gas recirculation |
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| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20201229 Termination date: 20211224 |