CN202648358U - System for drying lignite by exhausting furnace smoke for direct-fired pulverizing system of medium-speed coal mill - Google Patents
System for drying lignite by exhausting furnace smoke for direct-fired pulverizing system of medium-speed coal mill Download PDFInfo
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- CN202648358U CN202648358U CN 201220280717 CN201220280717U CN202648358U CN 202648358 U CN202648358 U CN 202648358U CN 201220280717 CN201220280717 CN 201220280717 CN 201220280717 U CN201220280717 U CN 201220280717U CN 202648358 U CN202648358 U CN 202648358U
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Abstract
The utility model relates to a system for drying lignite by exhausting furnace smoke for a direct-fired pulverizing system of a medium-speed coal mill, which is simple in structure, low in investment expense, capable of improving the adaptability of the pulverizing system to coal types, free from influence on the safety of a boiler, beneficial to the aspects of alleviation for the coking of a hearth, alleviation for the high-temperature corrosion of a water-cooling wall, reduction for the emission of NOx and the like, and capable of increasing the blending ratio of the lignite to be 0.4. The system comprises two recirculation pipelines which are connected with an economizer inlet flue of a shaft on the tail part of the boiler, each recirculation pipeline comprises a centrifugal fan with variable-frequency regulation, and an electric flashboard door I is arranged at the junction of the centrifugal fan with variable-frequency regulation and the economizer inlet flue; and an electric flashboard door II is arranged at the junction of the centrifugal fan with variable-frequency regulation and a hot primary air branch tube of the medium-speed coal mill.
Description
Technical field
The utility model relates to a kind of brown coal drying system, and especially a kind of medium-speed pulverizer unit pulverized-coal system is smoked stove drying brown coal system.
Background technology
Since coal market price liberalization in 2006, electric coal price lattice rise on the way, and the bituminous coal price is up to eight, 900 yuan per ton, and " coal electric shaft " policy can not in time be implemented in addition, and Thermal Power Enterprises is in the heavy losses state.Brown coal than horn of plenty, are characterized in that moisture is large, fugitive constituent is high at China's reserves, and the brown coal price is lower, about about 400 yuan per ton.It is few that China used the power plant of brown coal in the past, begins to mix burning brown coal for reducing some units that use bituminous coal of cost of electricity-generating.Because brown coal moisture is larger, it is not enough to mix behind the burning brown coal drying capacity of pulverized coal preparation system, and coal pulverizer goes out one's intention as revealed in what one says, the powder mixture temperature is on the low side (only having 55～60 ℃), has limited the ratio that burning brown coal is mixed in further increasing.
Thermal coal is by four classes that how much are divided into of its dry ash free basis volatile content: anthracite, meager coal, bituminous coal, brown coal.
Pulverized coal preparation system has numerous species, and at present operational performance is more and facts have proved it is that the pulverized coal preparation system of mature and reliable roughly has following several: low speed coal mill bin storage type pulverizing system, double-inlet double-outlet steel ball coal mill straight blowing type milling system, medium-speed pulverizer unit pulverized-coal system, blower mill unit pulverized-coal system.Pulverized coal preparation system is not omnipotent, and not all coal can burn, and every kind of pulverized coal preparation system has its applicable coal, is fit to use anthracite and Low Volatile Lean Coal such as the low speed coal mill bin storage type pulverizing system; The medium-speed pulverizer unit pulverized-coal system is fit to use the lower brown coal of high-volatile meager coal, bituminous coal and moisture; The double-inlet double-outlet steel ball coal mill straight blowing type milling system is fit to use anthracite, meager coal and bituminous coal; The blower mill unit pulverized-coal system is fit to use brown coal.
At first will determine the coal that this power plant will use after building up before building power plant, namely then so-called design coal selects suitable pulverized coal preparation system according to this coal.Can not all use design coal for various reasons after power plant builds up, need to mix and burn other coals, need in case of necessity original pulverized coal preparation system is transformed.Certainly, the transformation amount is less, the rear system of transformation is more simple better, and more complicated its safety and stability of pulverized coal preparation system is poorer, uses more in old unit such as the low speed coal mill bin storage type pulverizing system, but because its system is too complicated, newly-built power plant seldom uses this system.
The prior art that can improve the brown coal mixed-fuel burning proportion simply is described below: be provided with pre-drying device in the medium-speed pulverizer import, coal is undertaken predrying by drier in pre-drying device before entering coal pulverizer.Drier mixes by two ones: high-temperature flue gas and low-temperature furnace smoke.Bottom sides in pre-drying device is provided with exhaust outlet, and exhaust outlet is through the air inlet of Powder discharging fan connection medium-speed pulverizer, and exhaust is as required drier and the defeated powder medium of medium-speed pulverizer operation.Weary gas enters boiler through mill separator, weary gas and hot air blender, pulverized coal distributor and boiler-burner successively.Weary gas mixes in weary gas and hot air blender with hot blast.
Although the prior art can be mixed burning brown coal even whole burning brown coal by vast scale, but roughly there is the following shortcoming in it: the high-temperature flue gas that 1, extracts boiler furnace mixes with the cold smoke that extracts from boiler flue and carries out predrying to coal afterwards, contain unburnt pulverized coal particle in the high-temperature flue gas, pulverized coal particle is drawn out of and not only wastes fuel but also larger on the boiler combustion impact.2, be provided with pre-drying device in the medium-speed pulverizer import, the pre-drying device volume needs very huge drying medium fully to contact the predrying effect of playing with raw coal, now power plant is difficult to find the space to place pre-drying device between feeder and coal pulverizer for reducing very compact that the cost factory building all arranges.3, one of drying medium part is high-temperature flue gas; the high-temperature flue gas temperature is more than 1000 ℃; far exceed 600 ℃ of the temperature extremes that existing commonly used domestic steel can bear; need by add the insulation material head it off at steel pipe inner wall; but the steel pipe inner wall insulation material comes off in actual motion easily; the insulation material rear high-temperature flue gas that comes off can cause steel pipe to damage, and then causes unit by forced-stopping machine.4, for brown coal because its volatile matter is high, be prevent exploding, weary gas (being mixed by pulverized coal particle, flue gas, steam etc.) temperature usually requires to be lower than 65 ℃, and hot blast temperature is more than 300 ℃, and the weary gas of the prior art mixes easily in weary gas and hot air blender with hot blast and sets off an explosion.5, the medium-speed pulverizer unit pulverized-coal system of the prior art and active service differs greatly, if the active service unit is mixed the burning brown coal transformation, the renovation technique difficulty is large, improvement expenses is high.6, new power plant construction such as the need brown coal that all burn, blower mill or medium-speed pulverizer (medium-speed pulverizer can grind low-moisture brown coal) unit pulverized-coal system be generally acknowledge and also be the most suitable pulverized coal preparation system that uses brown coal that has been proved, the pulverized coal preparation system of the pulverized coal preparation system that the prior art is mentioned and the pure burning brown coal of active service differs greatly, and the prior art is not implemented, and its security, economy, stability are still waiting the check of time.
The utility model content
The purpose of this utility model is for overcoming the problem of above-mentioned prior art, providing a kind of medium-speed pulverizer unit pulverized-coal system to smoke stove drying brown coal system.Its system is simple, investment cost is not high, can improve pulverized coal preparation system to the adaptability of coal, on not impact of boiler safety, all be favourable alleviating the burner hearth coking, alleviating water wall high temperature corrosion and reduce the aspects such as NOx discharging, brown coal can be mixed burning and be increased to 0.4 than (mixing the ratio of amount with the boiler fired coal total amount of burning brown coal).
For achieving the above object, the utility model adopts following technical proposals:
A kind of medium-speed pulverizer unit pulverized-coal system is smoked stove drying brown coal system, it comprises two recirculating lines that are connected with the economizer gas approach of boiler tail vertical shaft, every recirculating line all comprises a variable frequency adjustment centrifugal blower, and variable frequency adjustment centrifugal blower and economizer gas approach junction are provided with electronic insertion plate door I; Heat primary air arm junction at variable frequency adjustment centrifugal blower and medium-speed pulverizer is provided with electronic insertion plate door II.
Described moderate oven cigarette is extracted out from the economizer gas approach of boiler tail vertical shaft arranged on left and right sides, adds the medium-speed pulverizer pulverized coal preparation system through the pressurization of variable frequency adjustment centrifugal blower by the heat primary air arm.
Described variable frequency adjustment centrifugal blower is arranged on the ground, boiler room.
Described heat primary air arm also is connected with air preheater, and air preheater is connected with primary air fan.
Medium-speed pulverizer unit pulverized-coal system of the present utility model is smoked stove drying brown coal system, comprises two variable frequency adjustment centrifugal blowers, four electronic insertion plate doors, some wear-resistant bends and some circular straighttubes.The moderate oven cigarette is extracted out from the economizer gas approach of boiler tail vertical shaft arranged on left and right sides, (flue gas is little negative pressure in the economizer gas approach to add the medium-speed pulverizer pulverized coal preparation system through the pressurization of variable frequency adjustment centrifugal blower by the heat primary air arm, the hot blast meter pressure is tens kPas in the heat primary air pipeline, and flue gas could add the heat primary air pipeline after need pressurizeing with the variable frequency adjustment centrifugal blower).The later pulverized coal preparation system of heat primary air arm access point remains unchanged, and this pulverized coal preparation system is the cold primary air fan pressurized direct pulverizing coal system of medium-speed pulverizer.
The utility model can improve pulverized coal preparation system to the adaptability of coal: also bituminous coal, brown coal are mixed burning but can burn separately bituminous coal.Then only need electronic insertion plate door I and electronic insertion plate door II are closed if burn separately bituminous coal, cut off the variable frequency adjustment centrifugal blower and get final product, switch flexibly.Extract the stove cigarette from the economizer gas approach, stove cigarette extraction amount is little, and little on the boiler combustion impact, variable frequency adjustment centrifugal blower power is little, and is easy to implement, with the obvious advantage.If the variable frequency adjustment centrifugal blower needs maintenance, can overhaul after electronic insertion plate door I and electronic insertion plate door II closed, the extraction amount of stove cigarette is regulated by the variable frequency adjustment centrifugal blower.Extract the scheme of flue gas compares with the scheme from one-sided extraction from the economizer gas approach of boiler tail vertical shaft arranged on left and right sides, little on flue gas flow field impact in the boiler tail vertical shaft, and two Fans operational reliabilitys (also can be moved if one of two Fans need to overhaul another than a Fans is high, just brown coal are mixed and are burnt than reducing), so adopt the scheme that extracts flue gas from the economizer gas approach of boiler tail vertical shaft arranged on left and right sides.
The utility model and prior art maximum different be following some:
(1) take out the stove smoke point and be selected in boiler tail vertical shaft economizer inlet flue duct, extracting the stove cigarette is the moderate oven cigarette, and temperature is less than 500 ℃, be lower than 600 ℃ of the temperature extremes that domestic steel commonly used can bear, take out the stove smoke pipeline and be easy to realize, do not need to add insulation material at inner-walls of duct, security of operation, stable.
(2) the moderate oven cigarette adds pulverized coal preparation system by the heat primary air arm, and system is simple, and reliability is high.
(3) the utility model is easy to realize.The medium-speed pulverizer unit pulverized-coal system of the pure burning bituminous coal of active service only need increase by two recirculating lines can realize that brown coal mix burning, and the renovation technique difficulty is little, improvement expenses is low, the transformation cycle short.
(4) heat is a minute grade, and the temperature more grade of high heat is higher.High-temperature flue gas belongs to the high-grade heat, and the prior art extracts the predrying brown coal of high-grade heat, and this part heat can not be used for heating superheated steam and reheated steam can cause unit efficiency to reduce, and more the multicomputer Efficiency Decreasing is more for the high-temperature flue gas of extraction.The utility model extracts the tow taste heat drying brown coal and can not cause unit efficiency to reduce.
The beneficial effects of the utility model are: adopt said system, can make coal pulverizer import desiccant temperature improve 20 ℃, coal pulverizer goes out one's intention as revealed in what one says, the powder mixture temperature improves 12～13 ℃, and brown coal are mixed and burnt than being increased to 0.4, can alleviate the burner hearth coking, alleviate water wall high temperature corrosion and reduce the NOx discharging.The utility model can make about 1,986 ten thousand yuan of the annual cost saving of a 300MW unit.
Description of drawings
Fig. 1 is the utility model system schematic.
Wherein, 1. economizer, 2. low temperature superheater, 3. electronic insertion plate door I, 4. variable frequency adjustment centrifugal blower, 5. electronic insertion plate door II, 6. air preheater, 7. primary air fan, 8. heat primary air arm, the 9. female pipe of heat primary air, 10. medium-speed pulverizer.
The specific embodiment
Below in conjunction with drawings and Examples the utility model is further specified.
As shown in Figure 1, it comprises two recirculating lines that are connected with economizer 1 gas approach of boiler tail vertical shaft, every recirculating line all comprises a variable frequency adjustment centrifugal blower 4, and variable frequency adjustment centrifugal blower 4 is provided with electronic insertion plate door I3 with economizer 1 gas approach junction; Heat primary air arm 8 junctions at variable frequency adjustment centrifugal blower 4 and medium-speed pulverizer 10 are provided with electronic insertion plate door II5.
The moderate oven cigarette is extracted out from economizer 1 gas approach of boiler tail vertical shaft arranged on left and right sides, adds pulverized coal preparation system through being arranged in ground variable frequency adjustment centrifugal blower 4 pressurizations in boiler room by heat primary air arm 8.The later pulverized coal preparation system of heat primary air arm 8 access points remains unchanged.The extraction amount of stove cigarette is regulated by variable frequency adjustment centrifugal blower 4.
Heat primary air arm 8 is connected with air preheater 6, the female pipe 9 of access heat primary air after heat primary air arm 8 is connected with the outlet conduit of variable frequency adjustment centrifugal blower 4 simultaneously, and each air preheater 6 is connected with a corresponding primary air fan 7.The pulverized coal particle of medium-speed pulverizer 10 outlets is carried by hot blast and flue gas and directly enters boiler combustion.
Claims (4)
1. a medium-speed pulverizer unit pulverized-coal system is smoked stove drying brown coal system, it is characterized in that, it comprises two recirculating lines that are connected with the economizer gas approach of boiler tail vertical shaft, every recirculating line all comprises a variable frequency adjustment centrifugal blower, and variable frequency adjustment centrifugal blower and economizer gas approach junction are provided with electronic insertion plate door I; Heat primary air arm junction at variable frequency adjustment centrifugal blower and medium-speed pulverizer is provided with electronic insertion plate door II.
2. medium-speed pulverizer unit pulverized-coal system as claimed in claim 1 is smoked stove drying brown coal system, it is characterized in that, described moderate oven cigarette is extracted out from the economizer gas approach of boiler tail vertical shaft arranged on left and right sides, adds the medium-speed pulverizer pulverized coal preparation system through the pressurization of variable frequency adjustment centrifugal blower by the heat primary air arm.
3. medium-speed pulverizer unit pulverized-coal system as claimed in claim 1 is smoked stove drying brown coal system, it is characterized in that, described variable frequency adjustment centrifugal blower is arranged on the ground, boiler room.
4. medium-speed pulverizer unit pulverized-coal system as claimed in claim 1 is smoked stove drying brown coal system, it is characterized in that, described heat primary air arm is connected with air preheater, the female pipe of access heat primary air after the heat primary air arm is connected with the outlet conduit of variable frequency adjustment centrifugal blower simultaneously, air preheater is connected with primary air fan.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220280717 CN202648358U (en) | 2012-06-14 | 2012-06-14 | System for drying lignite by exhausting furnace smoke for direct-fired pulverizing system of medium-speed coal mill |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220280717 CN202648358U (en) | 2012-06-14 | 2012-06-14 | System for drying lignite by exhausting furnace smoke for direct-fired pulverizing system of medium-speed coal mill |
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| CN202648358U true CN202648358U (en) | 2013-01-02 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201220280717 Expired - Lifetime CN202648358U (en) | 2012-06-14 | 2012-06-14 | System for drying lignite by exhausting furnace smoke for direct-fired pulverizing system of medium-speed coal mill |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105570924A (en) * | 2015-12-16 | 2016-05-11 | 华电电力科学研究院东北分院 | Method for substituting primary air heater and preventing explosion of coal pulverizing system through hot air recirculation |
| CN113819479A (en) * | 2021-11-01 | 2021-12-21 | 西安热工研究院有限公司 | System and method for improving drying output of medium-speed coal mill based on high-temperature furnace smoke pumping |
-
2012
- 2012-06-14 CN CN 201220280717 patent/CN202648358U/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105570924A (en) * | 2015-12-16 | 2016-05-11 | 华电电力科学研究院东北分院 | Method for substituting primary air heater and preventing explosion of coal pulverizing system through hot air recirculation |
| CN113819479A (en) * | 2021-11-01 | 2021-12-21 | 西安热工研究院有限公司 | System and method for improving drying output of medium-speed coal mill based on high-temperature furnace smoke pumping |
| CN113819479B (en) * | 2021-11-01 | 2022-09-30 | 西安热工研究院有限公司 | System and method for improving drying output of medium-speed coal mill based on high-temperature furnace smoke extraction |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term | ||
| CX01 | Expiry of patent term |
Granted publication date: 20130102 |