CN104864405A - Pulverized coal accumulation prevention fixing shrinkage cavity device with horizontally-arranged primary air pipes for boiler coal pulverizing system - Google Patents
Pulverized coal accumulation prevention fixing shrinkage cavity device with horizontally-arranged primary air pipes for boiler coal pulverizing system Download PDFInfo
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- CN104864405A CN104864405A CN201510285110.1A CN201510285110A CN104864405A CN 104864405 A CN104864405 A CN 104864405A CN 201510285110 A CN201510285110 A CN 201510285110A CN 104864405 A CN104864405 A CN 104864405A
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- pulverized coal
- shrinkage cavity
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- air pipes
- primary air
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Abstract
The invention discloses a pulverized coal accumulation prevention fixing shrinkage cavity device with horizontally-arranged primary air pipes for a boiler coal pulverizing system. The device comprises the horizontally-installed primary pulverized coal air pipes and fixing shrinkage cavities formed in the primary pulverized coal air pipes. The two sides of the lower end of each fixing shrinkage cavity are provided with slope-shaped pulverized coal accumulation prevention devices inclined downwards gradually to the two sides. The horizontally-installed pulverized coal accumulation prevention fixing shrinkage cavity device has the advantages that pulverized coal accumulation is prevented, and when existing, the pulverized coal will slip off along the slopes to be prevented from accumulating; the device has a throttling effect, and the speeds of the primary air pipes of a same-layer burner can be controlled to be uniform; after the pulverized coal accumulation prevention fixing shrinkage cavity device is horizontally installed, it is unnecessary to conduct a leveling test on the primary air pipes; the risk that pulverized coal accumulates on the upper portions of the horizontally-formed fixing shrinkage cavities and smolders to explode can be avoided; the horizontally-installed pulverized coal accumulation prevention fixing shrinkage cavity device has wear resistance.
Description
Technical field
The not accumulated powder that the present invention relates to a kind of boiler milling system primary air piping horizontally disposed fixes shrinkage cavity device, is applied to thermal power plant pulverized-coal fired boiler pulverized coal preparation system.
Background technology
Burner keeps suitable First air, Secondary Air and is separated burnout degree (OFA wind or SOFA wind) and exports even speed, is set up one of normal aerodynamic field and the necessary primary condition of smooth combustion.Too high can the postponement of primary air velocity is caught fire, too low then easy scaling loss burner, and in primary air piping, cause coal dust to deposit.The too high or too low normal hybrid perturbation that all may destroy air-flow of secondary wind speed.Thus reduce stability and the economy of burning.Being separated burnout degree is the fractional combustion wind controlling nitrogen oxide (NOx), within the specific limits, increases burnout degree and can reduce nitrogen oxide.Burnout degree affects boiler environmental-protecting performance.The size of burner outlet section and air velocity determine the percentage of primary air flow, secondary air flow and after-flame air quantity.This parameter is also that firing optimization needs to pay attention to.Especially primary air ratio, it and ignition process are closely related.Primary air ratio is larger, needing the heat of absorption just the more, thus reaching the required duration of catching fire just longer for reaching primary mixture ignition temperature.This fire coal low to volatile matter is very disadvantageous, more unfavorable when a wind-warm syndrome is lower.But, to the fire coal of high volatile, maintain fight not difficult, and after catching fire for ensure burning in time of volatile matter need higher primary air ratio.Boiler carries out needing when wind speed (air quantity) adjusts to consider security, economy and the feature of environmental protection.
In order to ensure boiler safety stabilize the economy environmental protection run, the layout of powder feeding pipes should make each powder feeding pipes air-flow and coal powder distribation even, the powder feeding pipes resistance of each burner should be as far as possible close, shrinkage cavity or other adjustment members can be installed if desired additional, by the shrinkage cavity on adjustment primary air piping, be not more than scholar 5% to make the deviate of the relative mean wind speed of each primary air piping maximum wind velocity.
Shrinkage cavity is the measure of a kind of fairly simple equal distribution stream and coal dust, and arrangement convenience, does not take up room.Shrinkage cavity mainly contains adjustable contraction and fixing shrinkage cavity two kinds.Adjustable contraction uses flexibly, as required, can carry out cold and hot state adjustment, but adjustment is complicated.Fixing shrinkage cavity structure is simple, do not need adjustment, but system needs accurate Calculation after installation, and when shrinkage cavity serious wear, pipeline enclosure allocation of the amount of air average deviation is comparatively large, when having a strong impact on stove combustion operating mode and boiler thermal output, needs to change shrinkage cavity orifice plate.
For 1000MW unit bituminous coal boiler, have 48 burners, combusting brown coal boiler-burner is more, if installation adjustable contraction adjustment workload is very large.Along with the development of Fluid Mechanics Computation technology, calculate accuracy and precision more and more higher, theory calculate meets completely installs fixing shrinkage cavity requirement.
Coal dust deposits in the duct for a long time and causes spontaneous combustion of pulverized coal, and coal dust temperature is higher, and spontaneous combustion is faster.Accumulated powder spontaneous combustion is the burning things which may cause a fire disaster producing blast.Therefore for preventing the blast of coal dust, should there is not projection and out-of-flatness place of retardance coal dust, avoid the deposition of coal dust in all another parts of pulverized coal preparation system.
Boiler coal-ash particle size great majority are less than 200 μm, and coal powder density is generally at 0.3kg/m
3~ 0.6kg/m
3between, be in and hold explosive dangerous concentrations scope most.
In boiler medium-speed pulverizer pulverized coal preparation system primary mixture, oxygen content is all greater than 14%, close to the oxygen amount in air, is in oxygen amount explosion ratio scope.
The shrinkage cavity of present use, time especially horizontally disposed, coal dust has a lot of depositions.
Summary of the invention
Goal of the invention: the not accumulated powder that the invention provides a kind of boiler milling system primary air piping horizontally disposed fixes shrinkage cavity device, object is to solve boiler milling system primary air piping vertically arranged shrinkage cavity accumulated powder problem.
Technical scheme: the present invention is achieved by the following technical solutions:
The horizontally disposed not accumulated powder of a kind of boiler milling system primary air piping fixes shrinkage cavity device, it is characterized in that: this device comprises the coal dust airduct that level is installed and the fixing shrinkage cavity be arranged in a coal dust airduct, is provided with the anti-accumulated powder device of the domatic shape downward-sloping gradually to both sides in the both sides, lower end of fixing shrinkage cavity.
Advantage and effect: the not accumulated powder that the invention provides a kind of boiler milling system primary air piping horizontally disposed fixes shrinkage cavity device, the position of accumulated powder may be produced in order to control coal dust pipeline, avoid coal dust to deposit to set off an explosion, the not accumulated powder that the level that devises is installed fixes shrinkage cavity, accumulated powder is not fixed shrinkage cavity device and can be used and the fixing shrinkage cavity same metal material used now, or uses wear-resisting nonmetallic materials.
Advantage of the present invention is as follows:
The not accumulated powder that level of the present invention is installed fixes shrinkage cavity device tool not accumulated powder feature, will avoid hoarding along with domatic landing when there being accumulated powder.
The present invention has throttling action, can control same grate firing burner each primary air piping speed even.
After the present invention's fixing shrinkage cavity device that accumulated powder level is not installed is installed, primary air piping does not need to carry out leveling test.
The fixing shrinkage cavity top accumulated powder that the present invention can avoid level to install glows risk of explosion.
The not accumulated powder that level of the present invention is installed is fixed shrinkage cavity device and is had wear-resistant feature.
accompanying drawing illustrates:
Schematic diagram is arranged in the fixing shrinkage cavity that the level that Fig. 1 uses now is installed;
Fig. 2 is that schematic diagram is arranged in the fixing shrinkage cavity that the level of the present invention's not accumulated powder is installed.
detailed description of the invention:below in conjunction with accompanying drawing, the present invention is described further:
As shown in Figure 1, the not accumulated powder that the invention provides a kind of boiler milling system primary air piping horizontally disposed fixes shrinkage cavity device, this device comprises the coal dust airduct 1 that level is installed and the fixing shrinkage cavity 2 be arranged in a coal dust airduct 1, is provided with the anti-accumulated powder device 3 of the domatic shape downward-sloping gradually to both sides in the both sides, lower end of fixing shrinkage cavity 2.Distinctive domatic anti-accumulated powder device 3 realizes the object avoiding accumulated powder.
Claims (1)
1. the not accumulated powder that a boiler milling system primary air piping is horizontally disposed fixes shrinkage cavity device, it is characterized in that: this device comprises the coal dust airduct (1) that level is installed and the fixing shrinkage cavity (2) be arranged in a coal dust airduct (1), is provided with the anti-accumulated powder device (3) of the domatic shape downward-sloping gradually to both sides in the both sides, lower end of fixing shrinkage cavity (2).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510285110.1A CN104864405A (en) | 2015-05-29 | 2015-05-29 | Pulverized coal accumulation prevention fixing shrinkage cavity device with horizontally-arranged primary air pipes for boiler coal pulverizing system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510285110.1A CN104864405A (en) | 2015-05-29 | 2015-05-29 | Pulverized coal accumulation prevention fixing shrinkage cavity device with horizontally-arranged primary air pipes for boiler coal pulverizing system |
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| Publication Number | Publication Date |
|---|---|
| CN104864405A true CN104864405A (en) | 2015-08-26 |
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| CN201510285110.1A Pending CN104864405A (en) | 2015-05-29 | 2015-05-29 | Pulverized coal accumulation prevention fixing shrinkage cavity device with horizontally-arranged primary air pipes for boiler coal pulverizing system |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07260106A (en) * | 1994-03-18 | 1995-10-13 | Hitachi Ltd | Pulverized coal firing burner and pulverized coal |
| GB2272755B (en) * | 1992-11-20 | 1996-05-15 | Northern Eng Ind | Pulverised fuel flow re-distributor |
| CN1477330A (en) * | 2003-06-23 | 2004-02-25 | 西安交通大学 | Radial gradient two air-controlled cyclone coal dust combustor |
| CN201396787Y (en) * | 2009-04-24 | 2010-02-03 | 中国航天空气动力技术研究院 | Double helix pneumatic nebulization tiny-oil ignition and combustion stabilization device |
| CN204717726U (en) * | 2015-05-29 | 2015-10-21 | 国家电网公司 | The horizontally disposed not accumulated powder of boiler milling system primary air piping fixes shrinkage cavity system |
-
2015
- 2015-05-29 CN CN201510285110.1A patent/CN104864405A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2272755B (en) * | 1992-11-20 | 1996-05-15 | Northern Eng Ind | Pulverised fuel flow re-distributor |
| JPH07260106A (en) * | 1994-03-18 | 1995-10-13 | Hitachi Ltd | Pulverized coal firing burner and pulverized coal |
| CN1477330A (en) * | 2003-06-23 | 2004-02-25 | 西安交通大学 | Radial gradient two air-controlled cyclone coal dust combustor |
| CN201396787Y (en) * | 2009-04-24 | 2010-02-03 | 中国航天空气动力技术研究院 | Double helix pneumatic nebulization tiny-oil ignition and combustion stabilization device |
| CN204717726U (en) * | 2015-05-29 | 2015-10-21 | 国家电网公司 | The horizontally disposed not accumulated powder of boiler milling system primary air piping fixes shrinkage cavity system |
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| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20150826 |
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| RJ01 | Rejection of invention patent application after publication |