CN213207829U - A high-efficiency wall-mounted air system to prevent high-temperature corrosion of water-cooled walls - Google Patents
A high-efficiency wall-mounted air system to prevent high-temperature corrosion of water-cooled walls Download PDFInfo
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- CN213207829U CN213207829U CN202020442618.4U CN202020442618U CN213207829U CN 213207829 U CN213207829 U CN 213207829U CN 202020442618 U CN202020442618 U CN 202020442618U CN 213207829 U CN213207829 U CN 213207829U
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- 238000005260 corrosion Methods 0.000 title claims abstract description 34
- 230000007797 corrosion Effects 0.000 title claims abstract description 34
- 238000002485 combustion reaction Methods 0.000 claims abstract description 18
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 10
- 230000009467 reduction Effects 0.000 claims description 5
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- 238000005259 measurement Methods 0.000 claims 2
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- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 9
- 238000005507 spraying Methods 0.000 description 9
- 239000003245 coal Substances 0.000 description 7
- 238000000034 method Methods 0.000 description 5
- 238000009991 scouring Methods 0.000 description 5
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- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
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- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
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Abstract
The utility model discloses a high-efficiency wall-attached air system for preventing high-temperature corrosion of a water-cooled wall, which is used for a front-wall and a rear-wall hedging combustion boiler and comprises a hot secondary air pipeline, a booster fan, a plurality of wall-attached air bellows, a plurality of wall-attached air branch pipes and a plurality of wall-attached air nozzles; a adherence wind bellows corresponds an adherence wind branch pipe and an adherence wind spout, and hot overgrate air pipeline is linked together through booster fan and the entry of each adherence wind bellows, and the export of each adherence wind bellows is linked together through the adherence wind spout that corresponds on adherence wind branch pipe that corresponds and the boiler side wall, and all adherence wind spouts divide into two sets ofly, and one of them group of adherence wind spout is located the left side wall of boiler, and another group of adherence wind spout is located the right side wall of boiler, be provided with the governing valve on the adherence wind branch pipe, boiler water-cooling wall high temperature corrosion problem can be solved to this system.
Description
Technical Field
The utility model belongs to the technical field of boiler combustion transformation, a high-efficient adherence wind system that is used for front and back wall offset combustion boiler to prevent water-cooling wall high temperature corrosion is related to.
Background
In recent years, along with the gradual strictness of environmental protection emission standards, most coal-fired power generating units in China are subjected to ultralow emission modification so as to meet the emission requirements of nitrogen oxides, sulfides and dust. With the operation of environmental protection facilities, the power plant has new problems while the pollutant emission reaches the standard. For example, in the low-nitrogen combustion system which is generally adopted at present, the whole main burner region is in an anoxic combustion state, so that the generation of a large amount of nitrogen oxides in the combustion process of pulverized coal is inhibited, but a large amount of CO and H are generated2And reducing gases such as S and the like cause high-temperature corrosion in a water-cooled wall area, and the safe and stable operation of the unit is seriously influenced. Therefore, how to adopt an effective and reasonable technical scheme to solve the high-temperature corrosion of the water wall area has important practical significance.
The front-back wall opposed firing system is applied more generally in present large capacity boiler, and this kind of combustion mode adopts the cyclone burner, can effectively improve the intensive mixing of buggy and air to improve the stability of burning. However, the side wall water-cooled wall is very susceptible to high temperature corrosion due to oxygen deficiency for several reasons:
in the combustion mode, secondary air enters from two ends of the air box, the burners are arranged along the width direction of the air box, two ends of static pressure in the air box are low, the middle of the static pressure is high, and the air inlet amount of the burners at two sides is less than that of the middle of the static pressure under the same opening degree of the air door.
The main combustion zone of the low-nitrogen burner is generally in an anoxic state, especially at the tail end of the jet flow. When the front wall and the rear wall are oppositely flushed and combusted, the airflow can wrap coal powder to move to the two side walls and combust, carbon particles which are not completely combusted at the tail part of the jet flow are extruded to the two side walls, water cooling walls of the side walls are directly flushed, and meanwhile, the air shortage in the middle parts of the two side walls is further aggravated.
In order to reduce nitrogen oxides, different types of cyclone combustors adopt some means to delay the mixing of pulverized coal particles and secondary air, such as enhancing the strength of the outer secondary cyclone, increasing the flaring angle of the outer secondary air, and adopting edge turning for a pulverized coal nozzle combustion stabilizing ring. The later the outer secondary air is mixed with the pulverized coal, the lower the burnout rate of the pulverized coal at the tail part of the jet flow is, and the more serious the air shortage condition of the side wall after the front wall and the rear wall are oppositely flushed is.
At present, the conventional solution for high-temperature corrosion of a water-cooled wall of a boiler reduces the sulfur content of coal as fired and adjusts operation parameters, and the other effective method is to form a layer of compact protective film on the surface of the water-cooled wall by spraying to block and slow down the reaction between the water-cooled wall and reducing gas, so that the corrosion rate of the water-cooled wall is reduced. Due to the limitation of the low-nitrogen combustion principle and the adjustment of the operation parameters, the problem of high-temperature corrosion of the water-cooled wall cannot be thoroughly solved; the water wall spraying is a passive protection mode, the water wall is protected from corrosion by the sacrificial coating material, and although the water wall spraying has a good protection effect, the water wall spraying has the problems of high cost, complex spraying process, limited service life and the like, so that the feasibility of solving the corrosion problem by only independently spraying the water wall is poor. Therefore, through targeted technical transformation, the flue gas atmosphere of the side wall water-cooled wall area is fundamentally improved, the problem of high-temperature corrosion of the boiler water-cooled wall is solved, and the method has important significance for long-term safe and stable operation of a unit.
SUMMERY OF THE UTILITY MODEL
An object of the utility model is to overcome above-mentioned prior art's shortcoming, provide a high-efficient adherence wind system that is used for front and back wall offset combustion boiler to prevent water-cooling wall high temperature corrosion, boiler water-cooling wall high temperature corrosion problem can be solved to this system.
In order to achieve the purpose, the high-efficiency wall-attached air system for preventing the water cooling wall of the front and rear wall opposed firing boiler from high-temperature corrosion comprises a hot secondary air pipeline, a booster fan, a plurality of wall-attached air bellows, a plurality of wall-attached air branch pipes and a plurality of wall-attached air nozzles;
one pastes wall wind bellows and corresponds a wall wind branch pipe and an adherence wind spout, and hot overgrate air pipeline is linked together through booster fan and the entry of each adherence wind bellows, and the export of each adherence wind bellows is linked together through the adherence wind branch pipe that corresponds and the adherence wind spout that corresponds on the boiler side wall, and all adherence wind spouts divide into two sets ofly, and one of them group of adherence wind spout is located the left side wall of boiler, and another group pastes the wall wind spout and is located the right side wall of boiler, be provided with the governing valve on the adherence wind branch pipe.
The inlet of the secondary air pipeline is communicated with the hot secondary air outlet of the air preheater.
The wall-attached air nozzles are circular air nozzles or rectangular air nozzles, wherein the circular air nozzles and the rectangular air nozzles are distributed on the wall on the left side of the boiler in a staggered mode in sequence, and the circular air nozzles and the rectangular air nozzles are distributed on the wall on the right side of the boiler in a staggered mode in sequence.
The injection direction of wall-adherent air sprayed from the wall-adherent air nozzles is parallel to the water-cooled wall of the side wall of the boiler.
The wall-mounted wind nozzles on the left wall of the boiler and the wall-mounted wind nozzles on the right wall of the boiler are symmetrically arranged front and back along the depth direction of the boiler, and are arranged in the middle-layer burner area, the upper-layer burner area and the reduction area between the upper-layer burner and the over-fire air along the height direction of the boiler.
The system also comprises a wall surface atmosphere measuring system for measuring the atmosphere of the wall surface of the side wall of the boiler in real time.
The utility model discloses following beneficial effect has:
the utility model discloses a high-efficient adherence wind system for preventing water-cooling wall high temperature corrosion of front and back wall hedging boiler when concrete operation, the hot overgrate air of hot overgrate air pipeline output enters into each adherence wind bellows after booster fan pressure boost, then spouts into in the furnace along the direction parallel with the boiler side wall through each adherence wind spout to form a layer of gas film on the side wall of boiler, keep off the scour of combustor flame efflux near boiler side wall position to the water-cooling wall through this gas film, alleviate the direct scour wear to the water-cooling wall; simultaneously, the hot overgrate air of introduction can supply oxygen in to furnace to improve the regional reducing atmosphere of boiler side wall water-cooling wall, make the high temperature corrosion degree of water-cooling wall reduce, simple structure, convenient operation, the practicality is extremely strong.
Drawings
Fig. 1 is a schematic structural view of the present invention;
fig. 2 is a distribution diagram of the nozzle of the present invention.
Wherein, 1 is a booster fan, 2 is an adherence wind bellows, 3 is a regulating valve, 4 is an adherence wind branch pipe, 5 is a round wind nozzle, 6 is a rectangular wind nozzle, and 7 is a wall surface atmosphere measuring system.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings:
referring to fig. 1 and 2, the high-efficiency wall-attached air system for preventing the high-temperature corrosion of the water wall of the front and rear wall opposed firing boiler of the present invention comprises a hot secondary air pipeline, a booster fan 1, a plurality of wall-attached air bellows 2, a plurality of wall-attached air branch pipes 4 and a plurality of wall-attached air nozzles; an adherence wind bellows 2 corresponds an adherence wind branch pipe 4 and an adherence wind spout, and hot overgrate air pipeline is linked together through booster fan 1 and each adherence wind bellows 2's entry, and the export of each adherence wind bellows 2 is linked together through the adherence wind spout that corresponds on corresponding adherence wind branch pipe 4 and the boiler side wall, and all adherence wind spouts divide into two sets ofly, and one of them group of adherence wind spout is located the left side wall of boiler, and another group of adherence wind spout is located the right side wall of boiler, be provided with governing valve 3 on the adherence wind branch pipe 4.
The inlet of the secondary air pipeline is communicated with the hot secondary air outlet of the air preheater; the wall-attached air nozzles are circular air nozzles 5 or rectangular air nozzles 6, wherein the circular air nozzles 5 and the rectangular air nozzles 6 are distributed on the left wall of the boiler in a staggered mode in sequence, and the circular air nozzles 5 and the rectangular air nozzles 6 are distributed on the right wall of the boiler in a staggered mode in sequence.
The injection direction of wall-adherent air sprayed from the wall-adherent air nozzles is parallel to the water-cooled wall of the side wall of the boiler; the wall-mounted wind nozzles on the left wall of the boiler and the wall-mounted wind nozzles on the right wall of the boiler are symmetrically arranged front and back along the depth direction of the boiler, and are arranged in the middle-layer burner area, the upper-layer burner area and the reduction area between the upper-layer burner and the over-fire air along the height direction of the boiler.
The utility model discloses a concrete working process does:
hot secondary air output by the hot secondary air pipeline enters each wall-attached air bellow 2 after being pressurized by a booster fan 1, and then is sprayed into a hearth along the direction parallel to the side wall of the boiler through each wall-attached air nozzle, so that a layer of air film is formed on the side wall of the boiler, the air film is used for resisting the scouring of flame jet flow of a burner close to the side wall of the boiler on the water-cooled wall, and the direct scouring abrasion of the water-cooled wall is reduced; meanwhile, the introduced hot secondary air can supplement oxygen into the hearth so as to improve the reducing atmosphere of a water-cooled wall area of the side wall of the boiler and reduce the high-temperature corrosion degree of the water-cooled wall. In addition, the wall surface atmosphere measuring system 7 can measure the wall surface atmosphere in real time, and the opening degree of each regulating valve 3 is controlled according to the wall surface atmosphere measuring system, so that the wall surface air volume is controlled.
The utility model introduces high-temperature hot secondary air into the hearth as wall-attached air, fundamentally improves the reducing atmosphere of the side wall water-cooled wall area, reduces the high-temperature corrosion degree of the side wall water-cooled wall, and simultaneously can not influence the original low-nitrogen combustion; secondly, in actual operation, according to the combustion characteristics of the front and rear wall opposed firing boilers, the air inlet position, the combination mode and the form of the wall-attached air nozzles of wall-attached air are accurately designed, meanwhile, wall atmosphere measuring points are arranged at the positions of the side walls for each wall-attached air nozzle, the wall atmosphere in the action range of the wall-attached air nozzles is monitored in real time, the opening degree of the adjusting valve 3 is automatically controlled through measuring feedback values, and then the air volume of the wall-attached air nozzles is adjusted to the optimal size. The utility model provides a traditional operational parameter adjustment receive equipment influence big, the limitation is strong and degree of regulation limited, the water-cooling wall spraying is with high costs, the technology is complicated and life is limited to and existing wall wind technical scheme influences big to boiler efficiency, coverage is limited and the not high scheduling problem of fail safe nature, and simple structure, reliable, the construction transformation degree of difficulty is low, the investment is little, to the water-cooling wall high temperature corrosion problem of wall hedging combustion boiler around solving, it has important meaning to realize unit safety and stability operation.
The utility model discloses select the hot overgrate air of air heater export as the wind regime, the hot overgrate air amount of wind of air heater export is sufficient, the temperature is high, free from impurity and be fit for directly getting into in the furnace as pasting wall wind. Hot secondary air is firstly pressurized by the booster fan 1, so that the hot secondary air has better rigidity after entering the hearth, and flame jet flow scouring close to the side wall burner is effectively resisted; hot secondary air pressurized by the booster fan 1 respectively enters the wall-sticking air bellows 2 in the left and right side wall areas, finally enters the hearth through the jet flow of the wall-sticking air nozzles through the distribution of the wall-sticking air branch pipes 4, the air quantity entering the hearth is determined by the wall surface atmosphere measuring system 7, and the opening degree of the corresponding regulating valve 3 is automatically controlled according to wall surface atmosphere measured values at different positions of the side wall, so that the wall-sticking air quantity corresponding to the wall-sticking air nozzles is controlled. The front wall and the rear wall of the opposed combustion boiler are correspondingly provided with a group of burners at the same height, so that two groups of wall-attached air nozzles are symmetrically arranged in the front and the rear direction along the side wall direction and are flushed by flame jet flows corresponding to the front wall and the rear wall burner nozzles, and the positions of the side wall-attached air nozzle groups, which are far away from the front wall and the rear wall, are specifically set according to different furnace sizes and by combining the lengths of the flame jet flows of the burner nozzles; according to a large number of actual operation and test conditions, the high-temperature corrosion of the side wall water-cooled wall mainly occurs in the elevation regions of the middle-layer combustor and the upper-layer combustor and the elevation region of a reduction area between the upper-layer combustor and the over-fire air, therefore, wall-attached air spraying groups are respectively arranged in the middle-layer combustor region, the upper-layer combustor region and the reduction area between the upper-layer combustor and the over-fire air along the height direction of a hearth, and the position of each wall-attached air spraying group is specifically set according to different furnace type sizes and in combination with the position of corrosion and abrasion under the actual operation condition.
Compared with a system and a method for arranging wall-attached air nozzles at the front wall and the rear wall, the high-temperature corrosion area of the boiler is mainly positioned at the high-temperature part of the side wall water-cooled wall close to the middle of the hearth, and the temperature of the two side parts close to the combustor is lower, so the design has the characteristics of large wall-attached air quantity, limited range, high initial speed and the like, thereby not only bringing the hidden danger of easy abrasion of the water-cooled wall of the area close to the nozzles, but also not well covering the high-temperature corrosion area because the range is attenuated quickly, and simultaneously reducing the combustion efficiency of the boiler because the extracted air quantity is overlarge.
The utility model forms a layer of air film with certain rigidity at the corresponding position of the side wall by taking a wind source from the outside as wall-attached wind to resist the scouring of flame jet of a burner near the position of the side wall to the water-cooled wall and reduce the direct scouring abrasion to the water-cooled wall; meanwhile, the introduced air can supplement oxygen to the hearth, so that the reducing atmosphere of the water-cooled wall area of the side wall is improved, and the high-temperature corrosion degree of the water-cooled wall is reduced.
Claims (6)
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| Application Number | Priority Date | Filing Date | Title |
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| CN202020442618.4U CN213207829U (en) | 2020-03-30 | 2020-03-30 | A high-efficiency wall-mounted air system to prevent high-temperature corrosion of water-cooled walls |
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| CN202020442618.4U CN213207829U (en) | 2020-03-30 | 2020-03-30 | A high-efficiency wall-mounted air system to prevent high-temperature corrosion of water-cooled walls |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111256111A (en) * | 2020-03-30 | 2020-06-09 | 西安热工研究院有限公司 | A high-efficiency wall-mounted air system and method for preventing high-temperature corrosion of water-cooled walls in front and rear wall hedging combustion boilers |
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- 2020-03-30 CN CN202020442618.4U patent/CN213207829U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111256111A (en) * | 2020-03-30 | 2020-06-09 | 西安热工研究院有限公司 | A high-efficiency wall-mounted air system and method for preventing high-temperature corrosion of water-cooled walls in front and rear wall hedging combustion boilers |
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