CN202813355U - Coal ash recalculating system capable of preventing boiler from being fouled - Google Patents
Coal ash recalculating system capable of preventing boiler from being fouled Download PDFInfo
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- CN202813355U CN202813355U CN2012204922103U CN201220492210U CN202813355U CN 202813355 U CN202813355 U CN 202813355U CN 2012204922103 U CN2012204922103 U CN 2012204922103U CN 201220492210 U CN201220492210 U CN 201220492210U CN 202813355 U CN202813355 U CN 202813355U
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- coal
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- coal ash
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E20/00—Combustion technologies with mitigation potential
- Y02E20/30—Technologies for a more efficient combustion or heat usage
Abstract
The utility model relates to a coal ash recalculating system capable of preventing a boiler from being fouled. The boiler operates for a period of time, required coal ash is introduced from an outlet of a dust collector and is conveyed to a coal mill through a returning device, the coal ash and raw coal are mixed in the coal mill according to a certain proportion, milled and dried, and is sprayed into a hearth through a combustor for combustion until being grinded to reach a particle size required by combustion; and with the flowing of smoke, the coal ash reacts with active Na in the smoke to generate a insoluble Na salt, and when the smoke passes through a platen superheater, the content of the active Na in the smoke is greatly reduced, and the smoke does not basically generate pollution because the content of the active Na in the smoke is preciously little when passing through a high temperature superheater and a high temperature reheater. According to the system, under the premise of keeping the basic form of the boiler unchangeable, the active Na in the smoke can be fixed to ensure that the active Na generates the insoluble Na without condensing and adhering on a convection heating surface, and thus the fouling is fundamentally solved.
Description
Technical field
The utility model relates to the boiler contamination technology that prevents, particularly a kind of system that prevents the flyash recirculation that boiler stains.
Background technology
China's power industry is take thermal power generation as main, and the thermoelectricity installed capacity surpasses more than 70%.The thermoelectricity steam coal adopts low grade coal inferior, to such an extent as to can cause the problems such as the slagging scorification of boiler furnace water-cooling wall, convection heating surface contamination, this series of problems is the key factor of the normal operation of the Long-term Effect station boiler.Slagging scorification and the meeting of contamination reduce the heat transfer efficiency of boiler, affect boiler output, so that the safety in operation of equipment seriously reduces, may cause the major accidents such as boiler flameout, booster, unplanned blowing out when slagging scorification is serious.
It is particularly serious to stain phenomenon when the eastern coal of the overbasic standard of burning, only has the lower coal of blending alkali metal content just can alleviate the contamination situation of convection heating surface.The high alkalinity coal accounts for 20% of coal resources in China recoverable amount, and present this part coal unrealized independent utility also can only be by mixing the mode section utilization of burning.Owing to contain the inherent characteristic of high alkalinity element (being mainly sodium element) in the coal, cause the combustion apparatus Boiler Heating Surfaces and stain serious, can not realize the pure burning utilization of accurate eastern coal and bring into play the advantages such as accurate eastern coal reserves reaches, price is low, cause being restricted for the extensive utilization of China's a large amount of high basic metal content coal, thereby restricted the efficient that coal resources in China is utilized.
The high alkalinity coal owing to the volatilization of alkali metal, forms one deck bottoming attachment in the boiler heating surface condensation easily in the coal powder boiler combustion process.The bottoming attachment is mainly with NaCl or Na
2SO
4Form exists, after mentioned component at high temperature volatilizees, easily condense in the ash deposition that forms sintering or bonding on the heating surface, along with the suction-operated of attachment to flying dust, meeting is so that contamination phenomenon in various degree appears in heating surface, and can't use soot blower to remove, thereby causes the heating surface heat-transfer capability to descend, cause the problems such as exhaust gas temperature rising, final reduction causes blowing out so that burner hearth is exerted oneself greatly.In addition on the one hand, stain and to cause flue blockage and corrosion booster when serious, alkali metal can form complex compound with the iron phase element, metal pipe-wall is formed the effect of biting of gnawing, so that metal heated compressive resistance reduces, cause the heat-transfer surface tube bank that booster occurs, have a strong impact on stability and the reliability of equipment operation.In a word, research high alkalinity coal utilization technique, reducing or solving the serious inclination to soiling of boiler is one of Important Problems of large-sized boiler safe operation.
It is domestic that coal utilization also lacks the engineering operation experience for the burning high alkalinity, only problem is stain in the burning of coal of research high alkalinity in the indivedual power plant of Xinjiang region, do not utilize efficiently at present way, the mode of only mixing burning by outer coal alleviates the contamination problem, outer coal is mixed the burning problem and is actually by adding other low alkalinity metal coals, has reduced alkali-metal relative amount in the raw coal.The ratio of Boiler Mixed Burning high alkalinity coal should not surpass 30%, and when mixed-fuel burning proportion increased, it is serious that convection heating surface stains dust stratification, forms the flue gas corridor, and sweep of gases causes high temperature reheater, high temperature superheater to leak.Because Xinjiang region high alkalinity coal utilization mode is electric power stations near coal-mines, the demand of mixing the external coal of burning mode is larger, and this mode often is subject to the restriction of traffic condition, has greatly increased operating cost.Therefore, the contamination problem of high alkalinity coal is problem demanding prompt solution.
Especially for power plant's operating π type boiler, coal dust burns in burner hearth, produce high-temperature flue gas and lime-ash, for the high alkalinity coal, alkali metal wherein at high temperature can volatilize with gaseous state, and flow to follow-up heat convection face with high-temperature flue gas, with after the lower heat convection face of temperature contacts, alkali metal can be deposited on the heat convection surface, and causes heating surface that phenomenon occurs to stain because have higher stickiness absorption flying dust.Owing to stain the generation of phenomenon, can cause convection heating surface heat exchange thermal resistance to increase, cause the phenomenons such as boiler output deficiency and even the blowing out of generation booster.
The utility model content
The utility model is for the contamination problem that exists in the existing high alkalinity coal utilization process, a kind of system that prevents the flyash recirculation that boiler stains is provided, this system architecture is simple, the purpose of seriously contamination of convection heating surface, high temperature corrosion and wearing and tearing in the time of can realizing greatly alleviating existing boilers of power plants high alkalinity coal, stablize boiler output, guarantee the boiler heating surface heat transfer effect, can avoid owing to stain the convection heating surface overheating problem that causes, reduce the generation of pipe explosion accident, reach the purpose of the extensive pure burning utilization that realizes the high alkalinity coal.
For solving the problems of the technologies described above, the technical solution of the utility model is as follows:
A kind of system that prevents the flyash recirculation that boiler stains, it is characterized in that: comprise coal pulverizer and deduster, the discharging opening of coal pulverizer is connected with boiler-burner, and the charging aperture of deduster is connected with the outlet of the air preheater of boiler back end ductwork; Described deduster is provided with two outlets, and an outlet is the outlet of output coal ash, and an outlet is returned the feeding mouth that the coal ash outlet is connected to coal pulverizer for returning the coal ash outlet; The feeding mouth of described coal pulverizer also connects the raw coal source.
Described returning between coal ash outlet and the coal pulverizer is provided with the foldback device.
Be provided with pendant superheater in the first paragraph flue of described boiler; Be provided with successively high temperature superheater and high temperature reheater in the middle flue backward.
Be provided with economizer in the back-end ductwork of described boiler, economizer is positioned at the air preheater front end.
The course of work of whole system is:
Before the initial operation of boiler, guarantee that by mixing burning low alkali coal or external flyash convection heating surface does not produce contamination; After operation a period of time, draw required flyash from the deduster outlet and be delivered to coal pulverizer by the foldback device, flyash and raw coal mix according to a certain percentage and grind and dry (can regulate this ratio by the contamination situation) in coal pulverizer, spray into the burner hearth internal combustion through burner after grinding the burning desired particle size; Along with flowing of flue gas, active Na in flyash and the flue gas instead gives birth to reaction and generates insoluble Na salt, active Na content reduces greatly in the flue gas when flue gas process pendant superheater, owing to active Na content in the flue gas is few, substantially do not stain when flue gas process high temperature superheater and high temperature reheater; Normally move for boiler can circulate always, need the flyash in the regular emptying deduster, guarantee SiO in the flyash
2Or the surplus of alumino-silicate is with the active Na in the fixing flue gas.
The principle of described system is as follows:
Boiler scaling stain with flue gas in the content of active Na direct relation (as: Na is arranged
2SO
4, NaCl etc.), if can reduce in the flue gas active Na share or make active Na change insoluble Na(lagoriolite etc. into), then can solve or alleviate from root the contamination situation of Boiler Convection Heating Surface.
Because the self-contained SiO that certain content is arranged in the flyash
2, Al
2O
3And other silicates, so the flyash re-using is fixed active Na steam in the flue gas, its reaction principle is as follows:
2NaCl+3SiO
2+H
2O
Na
2O
.3SiO
2+2HCl
Na
2SO
4+3SiO
2→Na
2O
.3SiO
2+SO
2+1/2O
2
Na
2O
.3SiO
2＋Al
2O
3-→Na
2O
.Al
2O
3 .2SiO
2+ SiO
2
2NaCl+H
2O+nSiO
2→Na
2O.nSiO
2+2HCl
Above-mentioned reaction is complete, makes volatilizable alkali metal chloride become aluminosilicate with sulfate conversion, has reduced the alkali-metal discharging of gas phase.
The beneficial effects of the utility model are as follows:
The utility model is to keep under the constant prerequisite of boiler citation form, the flyash that deduster is collected is back to coal pulverizer to be mixed with coal dust and sends into hearth combustion after grinding, the fixing active sodium in the flue gas in the combustion process, make it generate insoluble Na and can condensation not stick on the convection heating surface, fundamentally solved and stain the source that phenomenon occurs; Flyash is recycled in the coal pulverizer to mix with coal and grinds, and the self-contained heat of flyash can play the effect of dry coal dust, and flyash can better be mixed with coal dust, and it is better to enter behind the stove effect of the fixing active Na of flyash; On equipment, flyash produces from our factory's boiler combustion, only need install an ash transfer circuit additional gets final product, increase hardly power plant's operating cost, can also realize the pure burning utilization of high alkalinity coal, can solve or greatly alleviate convection heating surface and stain problem, increase power plant running time, improve power plant's operational efficiency.
Description of drawings
Fig. 1 is structural representation of the present utility model;
Wherein, Reference numeral is: 1 coal pulverizer, 2 burners, 3 pendant superheaters, 4 high temperature superheaters, 5 high temperature reheaters, 6 economizers, 7 air preheaters, 8 dedusters, 9 foldback devices.
The specific embodiment
As shown in Figure 1, a kind of system that prevents the flyash recirculation that boiler stains comprises coal pulverizer 1 and deduster 8, and the discharging opening of coal pulverizer 1 is connected with boiler-burner 2, and the charging aperture of deduster 8 is connected with the outlet of the air preheater of boiler back end ductwork 7; Described deduster 8 is provided with two outlets, and an outlet is the outlet of output coal ash, and an outlet is returned the feeding mouth that the coal ash outlet is connected to coal pulverizer 1 for returning the coal ash outlet; The feeding mouth of described coal pulverizer 1 also connects the raw coal source.
Described returning between coal ash outlet and the coal pulverizer 1 is provided with foldback device 9.
Be provided with pendant superheater 3 in the first paragraph flue of described boiler; Be provided with successively high temperature superheater 4 and high temperature reheater 5 in the middle flue backward.
Be provided with economizer 6 in the back-end ductwork of described boiler, economizer 6 is positioned at air preheater 7 front ends.
The course of work of whole system is:
Before the initial operation of boiler, guarantee that by mixing burning low alkali coal or external flyash convection heating surface does not produce contamination; After operation a period of time, draw required flyash from deduster 8 outlets and be delivered to coal pulverizer 1 by foldback device 9, flyash and raw coal mix according to a certain percentage and grind and dry (can regulate this ratio by the contamination situation) in coal pulverizer 1, spray into the burner hearth internal combustion through burner 2 after grinding the burning desired particle size; Along with flowing of flue gas, active Na in flyash and the flue gas instead gives birth to reaction and generates insoluble Na salt, active Na content reduces greatly in the flue gas when flue gas process pendant superheater 3, owing to active Na content in the flue gas is few, substantially do not stain when flue gas process high temperature superheater 4 and high temperature reheater 5; Normally move for boiler can circulate always, need the flyash in the regular emptying deduster 8, guarantee SiO in the flyash
2Or the surplus of alumino-silicate is with the active Na in the fixing flue gas.
The principle of described system is as follows:
Boiler scaling stain with flue gas in the content of active Na direct relation (as: Na is arranged
2SO
4, NaCl etc.), if can reduce in the flue gas active Na share or make active Na change insoluble Na(lagoriolite etc. into), then can solve or alleviate from root the contamination situation of Boiler Convection Heating Surface.
Because the self-contained SiO that certain content is arranged in the flyash
2, Al
2O
3And other silicates, so the flyash re-using is fixed active Na steam in the flue gas, its reaction principle is as follows:
2NaCl+3SiO
2+H
2O
Na
2O
.3SiO
2+2HCl
Na
2SO
4+3SiO
2→Na
2O
.3SiO
2+SO
2+1/2O
2
Na
2O
.3SiO
2＋Al
2O
3-→Na
2O
.Al
2O
3 .2SiO
2+ SiO
2
2NaCl+H
2O+nSiO
2→Na
2O.nSiO
2+2HCl
Above-mentioned reaction is complete, makes volatilizable alkali metal chloride become aluminosilicate with sulfate conversion, has reduced the alkali-metal discharging of gas phase.
Claims (4)
1. system that prevents the flyash recirculation that boiler stains, it is characterized in that: comprise coal pulverizer (1) and deduster (8), the discharging opening of coal pulverizer (1) is connected with boiler-burner (2), and the charging aperture of deduster (8) is connected with the outlet of the air preheater (7) of boiler back end ductwork; Described deduster (8) is provided with two outlets, and an outlet is the outlet of output coal ash, and an outlet is returned the feeding mouth that the coal ash outlet is connected to coal pulverizer (1) for returning the coal ash outlet; The feeding mouth of described coal pulverizer (1) also connects the raw coal source.
2. system according to claim 1 is characterized in that: described returning between coal ash outlet and the coal pulverizer (1) is provided with foldback device (9).
3. system according to claim 1 and 2 is characterized in that: be provided with pendant superheater (3) in the first paragraph flue of described boiler; Be provided with successively high temperature superheater (4) and high temperature reheater (5) in the middle flue backward.
4. system according to claim 3, it is characterized in that: be provided with economizer (6) in the back-end ductwork of described boiler, economizer (6) is positioned at air preheater (7) front end.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012204922103U CN202813355U (en) | 2012-09-25 | 2012-09-25 | Coal ash recalculating system capable of preventing boiler from being fouled |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012204922103U CN202813355U (en) | 2012-09-25 | 2012-09-25 | Coal ash recalculating system capable of preventing boiler from being fouled |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202813355U true CN202813355U (en) | 2013-03-20 |
Family
ID=47872220
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2012204922103U Expired - Lifetime CN202813355U (en) | 2012-09-25 | 2012-09-25 | Coal ash recalculating system capable of preventing boiler from being fouled |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN202813355U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102829472A (en) * | 2012-09-25 | 2012-12-19 | 中国东方电气集团有限公司 | Coal ash re-circulating method and system for preventing boiler from being contaminated |
| CN107854966A (en) * | 2017-11-20 | 2018-03-30 | 深圳东方锅炉控制有限公司 | A kind of method and system for improving high basic metal coal and staiing coking |
| CN110631004A (en) * | 2019-10-29 | 2019-12-31 | 华北电力大学 | Boiler system and method for reducing contamination and coking of high-sodium coal and removing heavy metal |
-
2012
- 2012-09-25 CN CN2012204922103U patent/CN202813355U/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102829472A (en) * | 2012-09-25 | 2012-12-19 | 中国东方电气集团有限公司 | Coal ash re-circulating method and system for preventing boiler from being contaminated |
| CN102829472B (en) * | 2012-09-25 | 2015-09-16 | 中国东方电气集团有限公司 | A kind of method and system of the flyash recirculation preventing boiler from staiing |
| CN107854966A (en) * | 2017-11-20 | 2018-03-30 | 深圳东方锅炉控制有限公司 | A kind of method and system for improving high basic metal coal and staiing coking |
| CN110631004A (en) * | 2019-10-29 | 2019-12-31 | 华北电力大学 | Boiler system and method for reducing contamination and coking of high-sodium coal and removing heavy metal |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20180428 Address after: 610000 18 West core road, hi-tech West District, Chengdu, Sichuan Patentee after: DONGFANG ELECTRIC Co.,Ltd. Address before: 610036 Shu Han Road, Jinniu District, Chengdu, Sichuan Province, No. 333 Patentee before: DONGFANG ELECTRIC Corp. |
|
| TR01 | Transfer of patent right | ||
| CX01 | Expiry of patent term |
Granted publication date: 20130320 |
|
| CX01 | Expiry of patent term |